Time is ticking away before Motorama 2013, and we still have some unfinished 'bots to deal with. There's a 12lb drumbot with a dead drive train, a fairyweight that needs some wiring sorted out, a featherweight needing assembly, and a walker that's still very much in kit form. Tonight we're going to start with the 30lb'er and see where we get to. Hit Back after viewing an image.
First job of the evening is to finish wiring the drive pods for the 30lb'er. We've already tested them to ensure proper orientation, so we have a pair of pods that are wired the same for proper forward rotation on one side, and another pair with swapped leads for the other side. We've marked the drive pods to indicate which is which, so we can quickly wire the spare pod to match as needed.
While we had the pods out, we hooked up the programming card and punched in some values we hoped would work. We've upped the reverse power to 100%, and set it to Low timing (for a low rpm/V motor), and also widened the deadband. It doesn't take long at all to set the values we want with this thing on all four pods - well worth the four dollars to avoid having to try it with the radio and beep codes.
Here we have all four drive pods sitting in place. Before we put over a couple of dozen bolts into this to hold down the pods we realized we needed to calibrate the throttle on the speed controllers, and the calibration button would be under the controller on the baseplate for two of the ESCs, so lucky we didn't bolt them all down yet! Here we had issues though. No matter what we tried, we couldn't get the ESCs to recognize the minimum throttle level (i.e. full reverse). We tried with and without the mixer, and also tried using different channels, but we just couldn't get the beeps. This is a problem, because the ESC needs full reverse to get the 'bot to run backwards. After a couple of frustrating hours, we posted online for some assistance, and moved on to something else.
That something else was punching the waterjetted parts out of the 24"x12" piece of quarter-inch thick 6061 aluminium. We have body parts, seven complete legs, and also a spare foot for good measure.
Here's the remnant the parts were punched out from - this may very well have to go up on the Build Space wall - it's not only pretty, but it's shiny too. We could probably have crammed a couple more parts on there as spares, but hopefully we have sufficient.
This is where we are with a full complement of legs and body pieces: 2lb 8.74oz. Factor in 18 x 9 grams = 162 grams or 0.36 pounds or 5.7 ounces worth of servos, and we still have half our weight allowance left for armour, electronics, a battery, and a weapon. Not bad - assuming it moves!
Now we have no doubt this 'bot will do well - the 'Bot Gods have their blood sacrifice! Actually, it looks worse than it really is, but it has to be done at least once per 'bot, it seems, and this one can be crossed off that particular list ...
On an initial check, we're going to have to clean up the parts somewhat with a file - you can see the leg servos don't quite fit in the thigh piece. We took out a file, and worked on squaring the corners inside the piece.
Success! Truthfully it didn't take very long, and wasn't that much effort, so we ran a file over all the other thigh pieces at the same time, along with one of the hip pieces where the third servo on the leg sits. We're also going to have to run all the parts on the belt sander to eliminate the waterjet tabs, but it's too late tonight to do that - we'll save that for another evening.
Moving down to our smallest unfinished 'bot, and here we have Lauren's fairyweight Tenacious Tinkerbell out for a test drive. We need to tidy up that wiring, but the 'bot is essentially done, and drives fairly well.
We crammed most of the wiring into various nooks and crannies in the 'bot, then added sufficient electrical tape to keep it all in place. Came out pretty well in the end. Not bad for a cheap and simple build. If we had to do it over, we'd probably swap the 10:1 motors for our favourite 30:1 motors, but we already had the 10:1s sitting around doing nothing, so there you go.
And a beauty shot. The CCD on our camera loves distorting colours - the 'bot is really more of a hot pink than a Ferrari red, but oh well.
Just for fun (and seeing as how they're all done except for stickers) here's Lauren's portion of the Team Radicus fleet for Motorama 2013. On the bottom, the twelve pound hobbyweight Steel Stiletto, in the middle the one pound antweight Malicious Mule, and on top the new fairyweight. That ought to keep her busy :-)
Tomorrow hopefully we can figure out the darned reverse on the 30lb'er speed controllers - we'll try using a different radio and receiver, to see if that makes a difference. We'll also run the walker parts across the belt sander and file them all to make sure the tabs fit the slots, and then we still have some work to put in on the hobbyweight to get the drive back up and running. Stay tuned - same 'bot time - same 'bot channel!
Tags: build, fairyweight, teti, featherweight, ii3, beetleweight, Hex1
We're reallllly close to having the Sportsman finished, so our goal this evening is to finish the 'bot and cross it off the To Do list. We only have a few things to wrap up, so fortified by a home-made pizza, it's time to hit the Build Space! Hit Back after viewing an image.
Issue number one is that we ended up with two different lengths of chain for the weapon transmission, which means something went awry here. After looking at it, we think we installed one of the weapon motor mounts upside down - they're not symmetrical.
So over to the drill press, and we put a couple of new holes in the mount after carefully taping up the motor so we don't get polycarbonate chips in it.We'll spare you the tapping photo :-)
With the mount reinstalled we took a moment to test the spin direction of the motor, and labelled the extension wires accordingly. We want to make sure the saw blades spin in the right direction after all.
We also took the bolts out of the polycarb mounts for the second and fourth mounting points, allowing them to essentially act as spacers, and that definitely helped eliminate some of the friction in the setup. As you can see in this photo we have grease on the the front panel and DeWalt mount, indicating it spun up, and we have [loud] video to prove it:
Success! There's still a little hesitation in the initial spin-up, but not enough to worry about - one half of the weapon is running finally, so it's on to the other side. We removed some of the bolts there too, and verified that both sides spun up at the flick of a switch on the transmitter. Hurrah!
And there we have it: a little over a year after beginning this 'bot, our first ever Sportsman class 'bot is complete: Palindrome30. This is going to be a really fun 'bot to play with, we can already tell. The weapon arrays may not be particularly effective when all is said and done, but it ought to be pretty durable, and hopefully we can keep it running long enough to win at least one match with it.
As you can see, weight is not at issue, at 26.2lb, but you'll also notice the 'bot sits nicely on it's side. This could be an issue, so with the remaining weight we're thinking we should cut some aluminium angle and bolt it to the sides to prevent it from sitting on the edge.
We also have a mild drive train problem to deal with - the keystock we put in is too small for the driven axle and the sprocket falls off. To fix this we need to disassemble the drive train and add a larger length of keystock. We took the side off, but notice the issue? The Nutstrip stops us from removing the wheels, so that had to come off too.
Here we're in the midst of reinstalling the sprockets, and while we're at it we added a couple of roll pins too, to ensure things stay nice and snug. So there we go, everything's been crossed off the To Do List for this 'bot, and 60% of the fleet is ready for Motorama 2013!
We still have a couple of hours left this evening, so it's time to change tack - from the biggest 'bot to the smallest, and we're working on Lauren's fairyweight Tenacious Tinkerbelle. We started with a weight check, and scared ourselves when the scale read 153 grams - before discovering there was an extra battery pack inside the chassis! With that put aside the 'bot weighs in at 140 grams out of the 150 allowed, so no worries there.
Tonight's efforts are mainly in the soldering arena - never our favourite occupation - so here we have the materials: the drive motors, which need extension leads added, and connectors for the batteries to make them compatible with our chargers.
Soldering the extension leads actually wasn't too painful. We did take the time to 'tin' all the ends, and that definitely helped when it was time to actually stick them together. We even went for some shrink wrap tubing to hide the evidence of the ugly soldering :-)
With all the extention leads done, we drilled the wheel hubs to 7/64" which is a hair under three millimeters, and pressed the wheels onto the motor shafts, then installed the motors back onto the base plate.
Whoo-hoo! UPS just came and dropped off a heavy, flat package. We quickly unwrapped it, and found this: the 1/4" 6061 aluminium plate with all the parts for the combat version of the hexapod walker - in order to save time and be able to ship this to us for the weekend, we asked Jake over at Westar Manufacturing (Team Whyachi) to leave everything unsnipped and unsanded - we can do that ourselves, and the resulting piece of waterjetting looks fantastic!
Anyway - back to the fairyweight. Here the receiver has been plopped into place on a piece of double-sided foam tape. We need to corral all the excess wire, and hook the speed controllers to the wheels and the battery, preferably incorporating the demo FingerTech power switch as we go.
Sorry for the blur - we were moving fast :-) This was supposed to be a shot of the new connector being installed to the battery so we could hook it up with the connectors we had lying around, rather than making a special purchase. We have two batteries to modify, and it doesn't take too long.
Here's a close-up of the FingerTech power switch with leads soldered to the tabs. It's actuated with a 3/32" hex key - clockwise for on and counter-clockwise for off, which is the reverse of the Whyachi power switches we're accustomed to, so we'll need to make a mental note of that.
Mid-way through the soldering, and things are going well, but there is a awful lot of wire to cram under the lid in this 'bot - we may have to add a few micro-sized zip ties to help keep things organized.
We're almost done - we have one side of the drive train soldered up to the ESCs, and the ESCs soldered to the wiring harness to connect to the battery. A few more connections for the other side of the drive train, and we'll be about done.
Ta-daa! Everything's been soldered together. We do need to drill a couple of holes in the back wall and mount the power switch properly, because the foam tape isn't holding up to screwing the switch on and off. We fired up the transmitter and calibrated the speed controllers, so that was a pretty good indication that things are soldered together properly.
A final piece of soldering for the night is in making a charging cable for the 'bot's battery. These batteries won't be balance-charged, but then again they're under five dollars apiece, so essentially they're considered disposable - if they can't take being charged regularly, we'll replace them.
Finally it's time to wrap up for the night. As you can see from the To Do Lists we've made quite a lot of progress - Lauren's fairyweight is ready for a test drive, we have a couple of tweaks to make to the other insect-'bots, a drive train to repair on the drumbot, a drive train to build for the featherweight, and a walker to assemble in the beetleweight category. Sounds like a lot, but we still have two weekends to go, so this ought to be eminently doable!
Tags: build, fairyweight, sportsman, teti, pal30
There's not much of a plan for today - just a desire to check things off our To Do Lists. We're waiting for parts at this point, but we ought to be able to make some progress anyhow. Hit Back after viewing an image.
We're going to pick up from where we left off yesterday, working on the chassis for Lauren's new fairyweight. We've screwed down the straight edges of the top and bottom plates, and they fit okay, so that's 50% of them done.
And following a trip around the belt sander, all the edges are flush with the chassis rails. Without the benefit of a waterjet, this was the easiest way we would think of to get these panels right. At 1/16", they're too thin to cut accurately on the table saw.
Next we scored a number of lines into the top and bottom, including additional bolt holes, motor mount locations, and wheel hole dimensions. Then we went on to secure the additional bolt holes, drill the motor mount locations, and begin drilling out the wheel holes.
It dawned on us we could do the wheel holes on Milly - we decided to go manual, because it would be faster than writing a script, lining up the 'bot, etc.
We drilled and tapped the motor mounts, and next looked at scoring them for the motor bolts to fix the motors to the mounts.
Meanwhile, we bolted together the featherweight chassis that we painted yesterday, and as you can see, we're only out of alignment on two bolt holes, so that's pretty good.
We also removed all the drive pods, as we need to mark and drill them for mounting the drive motors. Hopefully our gears will show up tomorrow, and we can assemble the mechanical portion of the drive train. The speed controllers should show up later in the week.
The drive motors for the fairyweight have been mounted, but we're beginning to see a problem ...
Oh, those darn wires - there's not sufficient clearance between the motors for the tabs and wire, so we decide to rotate the motors on their mounts 90 degrees on one side, and cram them in.
A final shot for tonight of the featherweight drive motors with mounting bolts. It doesn't seem like we did much today, but we definitely made progress. Tomorrow we're planning on using our 'bonus' build day to mount the drive motors in the featherweight, finish the drive train on the fairyweight, and see if we can make some Sportsman progress too!
Tags: fairyweight, featherweight, build, teti, ii3
This time in four weeks we'll be in Harrisburg, Pennsylvania, fighting it up in the arena, but to get there from here we need to finish putting together the rest of the fleet. Granted we're fifty percent of the way the there, but we really do want to get the remainder of the 'bots ready. We have three weekends, a spare day (Martin
Luther King Day) and plenty of evenings between then and now, and our To Do Lists are rapidly being crossed off. This weekend we want to get as much done on the featherweight as possible, so we're left with the drumbot, Sportsman, and beetle walker for the reaminder of the build time. Hit Back after viewing an image.
We start out today with a can of grey primer and some of the featherweight's walls. The back and sides get a coat, meanwhile we're working on the front wall, to be able to mount the wedge.
Unlike last time, we're not going to both making the wedge adjustable; instead we're going to make two wedges: one with virtually zero ground clearance, for fighting other wedges, and one with an eighth of an inch of clearance, for general purpose. Here we've drilled pilot holes in the front wall, that will be enlarged then tapped for 1/4"-20 bolts.
We'll spare you the drilling and tapping photos and take you to the [almost] finished product. We're pretty pleased with ourselves as far as accuracy goes, with all ten bolts going in without having to enlarge any holes in the wedge. We're going to countersink the wedge and use flathead bolts - this shot was just testing to make sure everything lined up.
On the other end of the size spectrum now, and we've cut rails for a 150 gram fairyweight. Lauren decided she wanted another 'bot to run on the Friday competition at Motorama, so we designed a scaled-down version of Malicious Mule, using the Pololu HP 10:1 motors we used at Franklin. The 'bot will be 3.5" square and five-eighths of an inch tall when completed, running on 1" foam wheels.
A subtle change in this photo - we've milled slots in the 1/8" 6061 aluminium front and rear walls. Next comes drilling and tapping for 0-80 screws.
Drat it! With two holes to go, out of 24 total we broke a tap - grrr! Fortunately we have one more, and carefully we finished up the tapping. There's enough of the broken tap sticking out that it can act as a 'peg' in the hole of the rear rail, and there are plenty of other screws helping to hold the 'bot together, so we're not too terribly worried about this one.
Flipping the scale switch again, and the paint has dried on the front wall for the featherweight, so we set about reassembling the chassis rails.
While the reassembly was going on, we checked weight on the fairyweight - we're suspecting we're going to be quite a bit underweight! Missing from the picture is the battery pack, which should be about 12 grams, power switch (a couple of grams) and motor mounts (a gram or two each), but there's also way too much polycarbonate there, so we'll see how it goes.
Here are some parts that showed up - the 180mAh 2S LiPo batteries for the new fairyweight, and a Car ESC programming card, for the ESCs we'll be using in both the drumbot and the featherweight. The instructions are amazingly amusing to read, and are in classic 'Engrish':"The two of all parameters can be set quantificationally". What?!
This is the remainder of the package's contents - five G25 710kV motors for Intrusive Interloper 3.0. Originally we were planning on using 610kV motors, but for some weird reason, Hobby King only allows you one per order, and we didn't want to have to pay five shipping charges, plus, as you'll see in a moment, these motors have slightly different dimensions than the 610kV ones.
Just for fun, the assembled chassis is sitting on top of a 3.5" floppy disk we scrounged up. For our younger viewers, a floppy disk was what we used before Thumb drives and cloud storage when we wanted to save documents or install programs. We have fond memories of installing Windows NT 3.51 from 33 sequential floppies ... those were the days! hehe
Here's the shiny new wedge installed on the featherweight. Although we have the motors, we're waiting on three deliveries before we can really get this 'bot up and running: ESCs from Hong Kong, gears from SDP/SI, and wheels from Canada. But hey - at least it was assembled in the USA :-)
Speaking of motors, we're flipping the orientation of the output shaft, which means removing the can, grinding new flats for set screws, and pressing the shaft down to the can with the arbor press. It's a fairly straight-forward operation, although we did find one of the set screws was stripped, so we're just going to have to brute force that shaft.
Here's one of the modified motors sitting in a drive pod. Notice that there's clearance between the end of the motor and the rear wall, so no need to mill pockets or drill holes for clearance. We do, however, need to drill mounting holes for the motors in all the drive pods, so we'd better bring our A[ccuracy]-Game to the marking and drilling tomorrow.
We don't have the benefit of a waterjet to cut the top and bottom plates for the new fairyweight, so instead we snipped out rough shapes from 1/16" polycarbonate with some scissors and then hit them with the belt sander to get them almost to size. The intention is to mount them to the chassis, and then sand off the excess in place, to ensure a perfect fit. We also need to drill out some wheel holes, of course.
While the belt sander was out, we took advantage of it to sand down some spare polycarbonate motor mounts to a half-inch tall, so we have them ready to drill and tap for the fairyweight.
Finally, we've finished modding all the drive motors for the 30lb'er, and we think we'll call it a night. All in all it's been a pretty productive day, and we still have two more days to build! Let's see where we're at come Monday evening ...
Tags: teti, ii3, build, fairyweight, featherweight
Today was one of those days where we got a lot done, but with very few pictures to prove it. The goal was to wrap up three more 'bots, and although we fell a bit short of that mark, we had a very productive day. Hit Back after viewing an image.
The weapon motor on Transcendental Terror 2.0 was not spinning up. We'd already identified one wire that was not connected properly, despite our best soldering efforts, and after pulling off the electrical tape, it was pretty easy to spot the same problem on the other two leads.
We broke out the crimper and PWM pins, and mechanically connected the motor to the speed controller. Finally, all was well. Time to bolt on the top plate and take the 'bot for a test drive.
No video at the moment - sorry - but the 'bot is pretty zippy on it's 3S battery and 30:1 HP Pololu motors. Final weight is 144 grams, out of 150 allowed, so no worries there, and the internal components are very tightly packed, so our worries about the side walls pivoting are essentially unfounded.
At this point we switched our attention to Belligerent Battler 1.0, which needs some upgrading done. We neglected to take any photos, but were able to cross a few things off the To Do List.
Switching focus again, this time to the hobbyweight Steel Stiletto. We used hacked brushless speed controllers in this 'bot at the last competition, and they worked fine, but in testing with the gyro we want to put in the 'bot, the ESCs would rhythmically 'pulse' on. We decided to switch to the configuration that worked in our 30lb'er - using Victor 883 speed controllers instead. We also took the time to update the 'bots paint job.
This is as far as we made it tonight - the 'bot is mostly assembled, but needs some additional wiring and internals installed. Then we'll put it through it's paces with the gyro and see if it's more controllable than last time. More to come tomorrow - same 'Bot Time, same 'Bot Channel.
Tags: build, beetleweight, fairyweight, hobbyweight, bb1, tt2, ss
This time in five weeks we'll be in the midst of the Motorama 2013 competition, yet at the moment we have zero 'bots ready to participate. Losing a week to the 'flu has definitely impacted the build schedule, so we'll just have to see how much we can get back on track. Today we're going to focus on the 'bots that are closest to being done, so we can cross some things off the list. Hit Back after viewing an image.
So here's something new to us - a BotBitz ANTSwitch. We figured out last time how it works, which sounds silly, as it's only a switch, but it wasn't as intuitive as you might think. The battery connector for the fairyweight has been cut to length, and we've soldered it to one side of the switch.
We soldered a random length of wire to the other side, and snipped holes in the polycarbonate casing of the switch for both wires. Due to the sloppy soldering the switch fits extremely snugly in the case, so no tape or bolts required.
More soldering - this time all the ground wires on the fairyweight are being soldered together: two drive ESCs, the weapon ESC, and the negative lead from the battery. Fiddly, but accomplished.
After soldering together all the positives too, we were about ready to give the 'bot it's test drive! There are a couple of minor issues to get out of the way first, such as ...
Trimming down the prop-saver bolts on the weapon motor, to ensure that they don't rub on the top plate. The already had been cut off, but as the top of the motor needs to fit in a hole in the top plate now, we wanted to trim them down entirely.
At this point we were ready for a test drive, and bolted down the lid, with all the components fitting nicely inside - yay! The 'bot was zippy, as you'd expect with Pololu HP 30:1 motors on 3S and 1.5" wheels, but the weapon wouldn't spin up. We had previously tested all the components before assembly, and everything was fine, so we're going to have to tear down the weapon assembly and see what's up.
Disappointed with the fairyweight, we decided to take a break from it, and take a look at the antweight. The issue here is that the weapon ring doesn't want to spin up. We decided to disengage one of the motors and see if that helped. It did. A lot. The ring spun up just fine on one motor, but pretty quickly slipped out of alignment.
So we needed something to keep the ring in alignment. Specifically what we needed was a 9/16" outer diameter washer. Not having any on hand, we took a 3/4" OD bronze thrust bearing and judiciously applied it to the belt sander, to whittle down the outside. Eventually we ended up with something fairly roundish, that fitted nicely.
Having formally decided to ditch the second motor - hey, instant spare! - we decided to upgrade the battery pack. You can see too that we're using a couple of bronze bushings to keep the thrust bushing in place on the standoff. With the original 470mAh battery pack, we're at 15.59 ounces, so we're pretty much good to go, finally, with this 'bot.
Happy that we finally have some progress made, we turned back to the fairyweight, and started disassembling the weapon. You can see the problem here - one of the motor leads did not 'stick' when we soldered it to the speed controller. At this point we spent a good ten to fifteen minutes trying to resolder it, but the solder simply would not 'stick' to the motor wire. Frustrated, we decided to go mechanical, and needed a simple, lightweight way to hook these wires up.
Remembering our experiences with the PWM cables from the other day, we decided to crimp a pin set to the wires, and just plug them together. The pins were a bit fiddly to deal with, as everything was still mounted in the 'bot, but it worked. We taped it up, and put the battery on the charger before testing again.
Meanwhile, back with the antweight, and we finally worked out the best arrangement of motor, idlers, and washers. The battery on top of the 'bot is just a test pack, but with this arrangement of the original two idlers at 3 o'clock and 9 o'clock, and the washers effectively taking the place of the second motor, straddling the 6 o'clock position, the ring remained engaged on the weapon motor, and all was well.
The day was surprisingly warm for a January day, and we took advantage of that to deposit some paint on the chassis of our hobbyweight Steel Stiletto. Unfortunately the photo doesn't do the paint colour justice - it's a pretty loud, neon pink - you'll have to see it in person to get the full effect :-)
One final check on Poor Punctuation and you can see we're cutting it pretty close - 451 grams (forgot to change the setting). One pound is 454 grams, so this is 15.9 ounces - fingers crossed the official NERC scale is in sync with ours.
We didn't have all the bolts in for that test, and so the two that were in unscrewed themselves, which let the weapon ring slip off the motor, hence the sparks you saw at the end, but the weapon did actually spin up, and with that, we can declare we have a working 'bot!
After looking at the field of fairyweights for Motorama 2013, they all have spinning weapons, so Lauren decided to scale down her pushy-'bot design to 150 grams, and gathered up some parts. We'll throw together some CAD designs for it, and make sure it'll make weight before committing to it.
Ta-daa! Presenting Poor Punctuation 2.5! The scrape on the top right, by the way, is from drilling the top plate (titanium) with a relatively dull drill bit to enlarge the hole for the top of the motor - the plate spun at the very end and scraped the paint a bit.
And a second Ta-daa! Presenting the rebuilt Malicious Mule. This time we think we have the right balance of speed and torque, still within a quarter-inch thick 6061 aluminium chassis. With both antweights done, we can get some skirmishing in between now and Motorama. We're wrapping up today with 20% of the fleet ready for Motorama - hurrah!
Tags: antweight, fairyweight, hobbyweight, build, pp2, tt2, mm, teti
We don't usually build on Friday evenings - it's typically pizza-and-a-movie night, but having lost a week of building to the 'flu, we need to regain time, so it's out to the Build Space we go. Hit Back after viewing an image.
After rummaging around in our boxes of bits, we found some PWM pins and housings. We weren't feeling entirely confident, but decided that the best way to reduce some of the cabling would be to cut them and put a new set of pins on the wires.
After a trip to our local Fry's, we had an appropriate crimper, and a few YouTube videos later, we decided to give it shot. As you can see, we did pretty well - hurrah!
A blurry shot of the weapon speed controller wire with it's new PWM connector on [much] shorter wire. We tested at this point, by plugging it in, and doing a quick spin of the weapon - it works! Now on to the drive ESCs.
While the cable editing was going on, we had been attempting to get Steel Stiletto to play nice with a gyro. We did find a gyro that seemed to work, but it also caused the drive wheels to 'pulse' on to a rhythm - not a good feature. It dawned on us that when we had the gyro working in Intrusive Interloper 2.0, it was with Victor speed controllers, rather than the BotBitz ones, so we decided to swap them out and put Victors back in the 'bot.
Back to the fairyweight, and the two drive speed controllers have had their PWM cables shortened and tested - everything is works still!
And things fit much better inside the chassis as a result. We still need to figure out what to do with the electrical wiring though ...
As a result of chopping down those PWM cables we've also chopped three grams out of the 'bot. No weight worries for us with this 'bot.
This shot was taken while we were trying to figure out how we're going to manage the electrical wiring. One thought was to have a removeable link, to allow us to keep the connector on the battery for charging, but there's simply not enough room inside the chassis for it. The soliution is still eluding us at this point ...
Last shot of the night, and we've drilled and tapped the Lite Flite wheel hubs with a #4-40 bolt to act as a retainer on the Pololu motor's D-shaped shaft. We'll add a dab of Shoe Goo too, once the wheels have been assembled.
Tags: build, fairyweight, hobbyweight, ss, tt2
Wow - a week of 2013 has gone by without a single build report. Unfortunately we were laid low by the 'flu going around, but now we're feeling a bit like our normal selves again, so it's out to the Build Space! Hit Back after viewing an image.
We started out with some fairly accurate drilling - axle and mounting holes for the Pololu motors in our rebuild of the fairyweight Transcendental Terror 2.0. Unfortunately our selection of metric screws on hand is limited, which is why one screw is in further than the other - to avoid the gears in the motors.
One of the speed controllers has a pretty short amount of wire between it and the motor, and we're good with that - the less wire the better, given how tightly everything is being packed into this 'bot!
The other speed controller needed it's wires trimmed and re-attached to the motor, so that meant our least-favourite job: soldering. Thankfully it goes quickly.
This somewhat blurry shot gives you an idea of how densely packed the internals are - and this isn't including the receiver. Not good ... how much can we eliminate in terms of wires - both power and PWM?
Here we're in the midst of trying to organize wires inside the 'bot to try and push them into nooks and crannies - without much success. Clearly, something has to give.
This is a close-up of a (dead) Fingertech Robotics tinyESC - we wanted to see whether it was feasible that we could de-solder the PWM cable, shorten it, and then solder it back on. In short, the answer is no - that circuit board is about half an inch by half an inch, and there's no way we have the soldering precision to take those three wires off without destroying the board. Kudos to Kurtis for his soldering abilities!
In desperation, we removed the balancing plug from the battery - these batteries are less than five dollars each, so if one gets out of balance - eh. We'll swap another in and call it good. We've also been able to cram all thge PWM cables into the 'bot, but the power leads are another matter. Hmm.
We wrapped up tonight by investigating the BotBitz ant switch. It didn't come with instructions, but after fiddling with it, and doing some Googling, we figured out that the wires solder to the pads on the side, access slots need to be cut into the outer casing for the wires, and the switch is turned on by screwing the screw all the way down. Time to ponder how to use this to keep the power wiring simple ...
Tags: build, fairyweight, tt2
Picking up from last night, we have some antweight issues to work out, and a fairyweight badly in need of some chassis parts. This is our last build session of 2012, so we want to make it count! Hit Back after viewing an image.
We now have all the parts and pieces for the fairyweight, so we've thrown them on the scale, and as you can see they weigh in at a nice 147 grams out of the 150 allowed. Factoring in the fact we're going to be chopping wires down, and added a couple of pieces of double-sided foam tape, we should still comfortably have a few grams to spare when all is said and done. To building!
Here we've mounted the weapon motor speed controller, and are in the process of soldering it to the weapon motor. Lots of wire trimmed off, and hopefully we can keep the fiddly soldering fairly neat.
A short while later and we have all three connections hooked up, and taped down to the baseplate, with plenty of clearance for the weapon blade above. Not a bad job, if we do say so ourselves.
Here's the result of some fairly accurate marking, punching, and drilling: #0-80 screws that have been pushed through the chassis walls. The key question is was this accurate enough to mate with the waterjet-cut top and bottom plates?
All six bolts line up virtually perfectly, and we're very happy about that. Can you figure out what we're not so happy about? An error in judgement has left the side walls with what is essentially a pivot point. The drive motors are going to be attached to these, so there's a real possibility of the drive motors splaying out as the 'bot moves. Hopefully the internals are compact enough to keep pressure on the walls, and prevent that from happening.
Here we've manually milled a small slot in the front wall for the weapon motor wires. All told this is coming together fairly nicely, which is a pleasant surprise for a 'bot this tiny.
We've mounted the battery with a small piece of padded foam tape, and tucked the balance cable back underneath itself. The receiver sits on top of the weapon ESC, and the drive ESCs sit between the two drive motors. Speaking of the drive motors, we're going to de-solder them from the ESCs and re-solder them with a fair length of wire chopped out. That means breaking out the soldering iron, which is an ideal time to procrastinate :-)
We had a pair of antweight issues yesterday - one was that the weapon on Poor Punctuation wouldn't spin up, and the other was that the batteries we had installed in Malicious Mule couldn't put out enough amps to turn the 'bot. We tried numerous different batteries in the pushy-'bot, and eventually decided that a 3S 950mAh 25C LiPo pack was sufficiently capable of giving the antweight oomph, but without being so crazily-fast that we needed the gyro, so we pulled the gyro and original packs, and installed the new pack. At 15.76 ounces we were good weight-wise, and the mix of speed and torque was about right for Lauren.
We were still stuck troubleshooting Poor Punctuation, and decided to fore-go removing the weapon motors again for today, and instead just have a skirmish between the two 'bots instead!
And a good time was had by all :-) Now, though, it's time to clean up, order up some Indian food, and throw a Mystery Science Theater 3000 on the TV, and count down to midnight, and 2013. Happy New Year to everyone!
Tags: antweight, fairyweight, build, tt2, pp2, mm
Having spent yesterday playing with our Hexy Kit, we decided to spend some time on the rest of the fleet for Motorama 2013 today, so we picked up a bunch of parts that arrived while we were out of town earlier this week. Hit Back after viewing an image.
The first parts out of the box are top and bottom plates for our antweight Poor Punctuation 2.0. These 0.032" titanium pieces are to replace the 1/16" polycarbonate that the bolts pulled through last time out. There shouldn't be any way those bolts are pulling out this time!
From the same 0.032" titanium we had top and bottom plates cut for our smallest 'bot, Transcendental Terror 1.0. The intention is to ensure that the 'bot can run inverted this time around, which is why the top and bottom look the same.
Here are some polycarbonate parts for Lauren's antweight Malicious Mule: top and bottom plates cut from 1/8" and some motor mounts cut from 1/4".
Here are some miscellaneous parts for a comical beetleweight design, Lincoln Limboer 0.9. We probably won't take this 'bot to Motorama, but you never know ...
All our spare motor mounts - universal press-on mounts for all the Pololu motors we use on the top, and clamp-style mounts that are also good for the Pololu-type motors, but can also be used for bolting into the front of the motor.
Some heftier half-inch polycarbonate parts for our featherweight redesign, Intrusive Interloper 3.0 - enough parts to make five of the drive pods we're going to build. Guess we should think about ordering some motors, ESCs, and gears, eh?
More parts for the featherweight: top and bottom plates cut from 0.071" titanium. The top plate has a battery access panel cut out of it, to make swapping the battery significantly easier between matches - three bolts beats 46!
Some simple marking to begin with, using the calipers to etch the midline of the polycarbonate parts for the 30lb'er in preparation for drilling and tapping. At least it's unlikely we'll break a tap in plastic ...
Here we've thrown together the parts in hand for Malicious Mule, and realized that we were supposed to slot the front and rear walls for the side rails, so we load those up on Milly and let her at it.
While Milly is doing her thing, we broke out the primer and gave the 0.032" titanium parts a basecoat. Almost time to get a new can of this stuff, but it does seem to help.
While the primer's drying we turn our attention to the featherweight, and having already slotted the front and rear walls, we can put the chassis together and check the top and bottom panels. The walls will need a turn on Milly to cut a 0.071" lip for the top and bottom panels to sit in.
Here's a quick mock-up of the drive pods in the body of the 'bot. Looking forward to seeing these in action with snazzy FingerTech wheels. Hopefully they'll hold up [crosses fingers].
Here's a quick weight check for the fairyweight - it's currently running at 96 grams out of the allowed 150, with all the internals. That leaves 54 grams for the chassis, and the top and bottom plates are 19 grams each, taking us to 34 grams left for the walls and bolts. Shouldn't be a problem.
The primer's dried, so it's on to a covering of Team Radicus Purple. Still haven't figured out why it always photos as more of a blue, but no matter.
Milly's done her thing with the front and rear walls for Malicious Mule, and here's a test fit - looks good. Next to do is drill and tap the walls and motor mounts. Oh, we'd better order some motors too ...
This slightly blurry shot was taken after finally managing to install the weapon onto the base plate of Transcendental Terror 1.0 - those #2 screws and nuts are fiddly, but we got there eventually! The motor leans forward very slightly due to the wires that protrude from the underside - we were originally going to run them under the 'bot, but this will work just fine.
Here we're testing clearance on the top plate - looking good! We will Dremel down the prop-saver bolts a touch more just to be on the safe side, but really the next big thing to do for this 'bot is cut the chassis walls.
The CAD model said everything should fit, but looking at things in real life we have our doubts, but we're going to soldier on anyhow, and make it all fit, by hook or by crook.
Malicious Mule's drive train upgrade involves using proper axles - specifically ones from FingerTech designed for Lite Flite wheels. We've drilled the hubs out to 5/32" and they fit nicely. We're going to cut off that excess on the left hand side, and use a dab of glue to secure the shaft to the hub.
All four axles/hubs/wheels are ready to be attached to the drive motors next weekend. We want that part of the build to go smoothly, and have everything ready for when the motors come in ...
... So we'd better get on and drill and tap the motor mounts. Actually, as we had everything lined it, it was time to break for dinner, so we'll pick this up [hopefully] tomorrow evening - Same 'Bot Time, Same 'Bot Channel!
Tags: antweight, fairyweight, featherweight, mm, ii3, tt1, pp2, build
For whatever reason we didn't take very many photos today, but we did get some work done. We wanted to tidy up the carcas of our previous fairyweight, contemplate an alternate fairy, and make some progress on the Sportsman. Hit Back after viewing an image.
We pulled four mystery Pololu-style motors, with wheels, and they weighed 2 ounces. A fairyweight is allowed 5.3 ounces, so it could be feasible that we could build an indestructible fairyweight version of Intrusive Interloper for Motorama, but really that was just fiddling. We did disassemble Transcendental Terror 1.0 and clip out the juicy internals. All told, the motors, weapon, battery and wheels came in at 90 grams, which is what we expected, so with the titanium and UHMW chassis components to come we should be fairly clean sailing to making weight.
The other 'bot we spent some time on today was the Sportsman Palindrome30 which is coming together nicely. We fixed up a pair of dead DeWalts with replacement motors, and installed a pair of Victor 883s from our featherweight - it'll be going brishless in the next version, so we have the Victors to spare - and installed those too. The power switches are installed - 4S LiPo for the weapon and 6S LiPo for the drive.
At this point it was time to wrap up, and go clean up for dinner, but with any luck the parts for the fairyweight will come by next weekend, and we can wrap up that build stat!
Tags: build, fairyweight, sportsman, tt2, pal30
Back at Motorama 2012 we debuted a new fairyweight, Trancendental Terror 1.0, with a titanium spinning blade attached directly to the motor driving it. It was a decent design, but it had one fatal flaw - it wasn't invertible, and lost two out of three matches by being flipped. We decided to see if we could tweak the design to make it invertible. Hit Back after viewing an image.
Here's where we started, by sketching to try and lay out the components. This was our third attempt, and happy with it we decided to switch to CAD and see if it would make weight.
The baseplate went through a few iterations as we trimmed more and more weight off the design aiming for that magical 150 gram mark. The baseplate is 0.03" titanium, waterjet-cut, along with the plates for our antweight.
The chassis walls were originally designed to be 1/8"-thick polycarbonate pieces - we didn't want to do the one-piece chassis block like last time because it was awkward to work with. Just to give a sense of scale, the chassis is roughly three inches across.
One thing we're keeping from the first version is bolting through the 'bot to keep it together. These are 7/8"-long #0-80 screws and nuts. Note the notch in the front wall for the weapon motor wires.
With the baseplate on, we've also mounted the Pololu 30:1 HP drive motors, which will have 1.5" Lite Flite wheels attached for the drive train. We know from our antweight these will be more than enough to make the 'bot mobile.
The weapon motor and blade combo are transplanted directly from the first version, but sit parallel to the base of the 'bot, rather than angled, and the whole 'bot will be angled anyhow, due to the size of the drive wheels.
Next we need to pack the electronics in the 'bot. The green boxes at the back approximate the FingerTech TinyESCs we'll be using; the large blue box is a 3S 180mAh LiPo battery pack; the transparent orange is the OrangeRx receiver; and finally under that is a 10A brushless motor controller for the weapon motor. Not shown is a BotBitz power switch which will be mounted over the two drive ESCs.
And here's the 'bot all bolted up. The hole in the top plate is simply because we didn't want to design different top and bottom plates - this way we can have three identical ones cut, and use them interchangeably. The 'bot actually rides on the front lip of the baseplate, and if it ends up flipped, it'll ride on the same point on the top panel.
As we're bolting through the walls, they don't need to be able to hold a thread, and so we could switch the polycarbonate for UHMW, which would save a few grams of weight, plus it comes in black, so we'll paint the top and bottom in Team Radicus purple.
Adding it all up, we have a few grams free, but this doesn't include the four bolts for the weapon motor and six bolts for the body, but then again this also shows polycarbonate walls, not UHMW, so we're thinking that all-in-all we can safely make weight.
Tags: design, fairyweight, tt2
The last two days we were on the road ... it was a relatively dull drive, which is a good thing: no speeding tickets and decent time, despite the near-constant rain through Arkansas and Tennessee we made good time to the hotel the first night and the Competition Hotel Thursday night. A gin and tonic or two the night before, and we were up and ready for Robot fights this morning. Hit Back after viewing an image.
Our hotel room this time has a stand-alone hearth, which is actually pretty neat, but still: we mustn't dwell - this is the first day of competition and we have 'bots to fight!
We made it to the arena about 8am after a quick diversion for coffee, and took a pair of tables near the main arena area after hopping a ride in with a quad-ride which was much easier this year due to the investment in the additional container for all our small parts. At arena-side there wasn't much happening yet, as the small arena was still being constructed, so we went back to work on our Sportsman.
We were pitted next to Mike and Julie of Near Chaos Robotics, and Mike was good enough to lend us an extension cable for the drill press - Thanks Mike! It's quite a nice feeling to roll into the pits and not be franticly wiring something at the last minute. We had eight 'bots ready to fight, and the Sportsman was really a distraction - we were going to put some effort into getting it ready, but not worry too much if it doesn't get done in time.
For the first couple of hours it was just Sportsman-building and battery-charging, but the small arena had been assembled, and safety inspections for the fairies and ants started. Transcendental Terror 1.0, Poor Punctuation 2.0, and Malicious Mule all passed without a hitch, so all that was left to do was to wait for the brackets to be generated, and the fights to start!
As it turned out, Lauren was going to be thrown into the pool at the deep end - not only as one of the very first matches, but against a nasty-looking beater called OverClock. Here we go, then, the first match for a first-time participant:
YAY! A win! It should be confessed that Toni was more than a little jealous, having had to go through about five competitions before ever winning a match, but we suppose the experience helped, and Malicious Mule collected a winner's pog! Hurrah! Lauren did a pretty good job driving, and after the match we checked out the 'bot, but there didn't seem to be any damage at all, so the battery was put on the charger (not that it really needed it) and we lined up for our next match: Poor Punctuation 2.0 versus Mateo:
Well, darn it - the judges gave the win to Mateo, and we were left scratching our heads as to why the weapon hadn't spun up - it had worked just fine back at the Build Space, so something must have gotten out of alignment, so we headed back to the pits to take the top off and take a look. There didn't seem to be anything specific - the weapon motor gears and the idlers all looked to be engaged with the weapon ring gear ... hopefully we'll see signs of life from the weapon in Poor Punctuation 2.0's next match, but right now we're headed back to the arena for Malicious Mule's next fight, against Ferocious:
It looked from the outset that Ferocious had one side of the drive train out, and once again Lauren did a good job driving Malicious Mule, but the judges gave this match to Ferocious, presumably because it appeared to be engaging us more than the other way around. Again, though, no damage so the 'bot went back on the charger, and we had a little time to take a breather. Lauren's cousin and her husband had come out to visit, and they enjoyed themselves watching the matches, and generally catching up.
Next it was the turn of our smallest 'bot, Transcendental Terror 1.0 to head into the ring, up against a hacked R/C car called Rosie the Littler:
Unfortunately the blade on our fairyweight kept getting stuck in the thin aluminium on the front of the opponent, rather than really doing any major damage, so we spent a fair bit of time locked together during this match, but the Pololu motors on Transcendental Terror 1.0 were more than up to the job of running both locked 'bots around the arena, until eventually Rosie the Littler tapped out. A debut win for the fairyweight - yay! The next match rolled around quickly: Malicious Mule versus the spinning bar of Odahviing:
As with the match against OverClock, Lauren was able to drive Malicious Mule straight into the weapon of Odahviing, disabling it! From there it became a game of "Chase Me" as Odahviing kept running for space to be able to try and spin it's blade up again, while Malicious Mule kept after its opponent. Lauren had more pushing power, and with the weapon out of action, by the time the match went to the judges, it was fairly clear that Malicious Mule had prevailed! Yay! Again, the 'bot was put on the charger, and we lined up the next match, which was Poor Punctuation 2.0 versus Gyroscopic:
Grr! Again, the weapon wouldn't spin up, and without it we were ravaged by Gyroscopic, who put some good hits on Poor Punctuation 2.0, although in re-watching the video, we also caused Gyroscopic to take a few flips too! All in all, a fun match, but the last hit from our opponent split our antweight open, and we tapped out, as we didn't want to lose any of the internal components to another hit. We didn't have much time to mourn the antweight crashing out of the competition zero and two, because the fairyweight was up next!
An early hit on lolcat appeared to have knocked out one side of its drive, but we weren't in a position to capitalize on that fact, as we were upside down, and unable to right ourselves. Unfortunately the wheels on Trancendental Terror 1.0 weren't quite big enough for the 'bot to be able to drive inverted - oops! So although we were able to get a little motion, we had to hope a hit from lolcat would right us, but with one side of its drive out, lolcat had issues getting to us for that hit, until eventually we burned out the speed controller for the weapon motor, which was also powering our receiver, and the 'bot was dead.
Back at the pit table we had some time before the next match, so we pulled a speed controller from Poor Punctuation 2.0, scrounged some solder from Mike (thanks again Mike!), and replaced the controller in Transcendental Terror 1.0, getting it working again - phew! After that repair, we had a few more minutes free, then it was time to line up for another match with the star rookie: Malicious Mule versus KnightLight.
A tough match for Malicious Mule - a faster opponent with a veteran driver, but early on it appeared that one side of KnightLight's drive gave out, and Lauren was able to pin KnightLight repeatedly, winning the judges' vote at the end of the match! Three wins! Hurrah! There was a bit of breathing room, so the 'bot went back on the charger, and we waited for the next match to come up on screen. As it turned out it was Malicious Mule again, and against another fast, experienced wedge again, although this time it was our pit neighbour Mike, with Kobalos:
Phew! A very tough opponent and with its years-old Copal motors Malicious Mule was outclassed by Kobalos, leaving us with a second loss, and Malicious Mule was done for the day, but with a very respectable 3-2 record! Well done Lauren! We still have one 'bot running, and it's time for another match: Transcendental Terror 1.0 against Kongol:
Something was up with our 'bot - one side of the drive wasn't running, but the first hit was a good one, flipping both us and Kongol, although only one of us was able to self-right, and it wasn't us! With the next hit we took the saw blade off Kongol and cut his weapon motor wires, but unfortunately we were stuck on our back unable to show any movement, so Transcendental Terror 1.0 was counted out for lack of movement, a Technical Knock Out for Kongol.
For the rest of the afternoon we watched some matches, tinkered with the Sportsman, and chatted with Lauren's cousin and husband. At the end of the day, we packed away the 'bots, and headed back to the hotel for some pizza, a shower, and a good night's sleep!
Tags: motorama, competition, fairyweight, antweight, mm, pp2, tt1
Having dashed out at lunchtime to Grainger to swipe some #2-56 x 3/8" screws we were hoping to get the smallest 'bot in the fleet for Motorama 2012 finished up tonight. There's not much to do,so we buckled down and set to it. Hit Back after viewing an image.
It didn't take very long to get the new bolts broken out and installed for the weapon motor. Although there are only two screws they seem very secure, so out excessive milling doesn't seem to have caused too many issues.
There's still - unfortunately - a bit of soldering to be done, but it's relatively straight-foward as we're connecting the weapon motor to the weapon ESC.
We left the leads as they were to have plenty of manoueverability taking the 'bot apart, wrapping the soldered connections in electrical tape to insulate them.
Everything looks good, and a test on the scale says 148 grams out of the 150 allowed, so we should be good to go with this 'bot! It's nice to have another one done, and the night is still young, so we can now turn our attention to another member of the fleet ...
Bonus! We have a box that fits this 'bot - the box our first featherweight's weapon motor came in, but it houses our smallest 'bot just fine ...
Tags: build, done, fairyweight, tt1
This time in two weeks we'll be on the road to Nashville, on the way to Motorama 2012! Which is exciting, but we still have work to do - the plan is to finish the fairyweight and a beetleweight by the weekend, and then spend the weekend working on the two biggest
'bots. In order to manage that we need to fabricate some parts, and put a call in to Chris over at Speedster Hobbies to see whether we could get some shop time, and Chris graciously agreed. We jumped in the BotMobile with some materials and headed his way. Hit Back after viewing an image.
Chris reminded us of how the bandsaw worked, and we started out by chopping up some aluminium and steel. Boy, we wish we had one of these in the Build Space! Nifty!
Here's what we cut up - DeWalt drive axles, a weapon transmission shaft, two pairs of blade shafts (steel and aluminium), wheel hubs, and trimmed down the blade shaft and retainer for the 30lb'er.
After a spell on the lathe, we had the aluminium round turned down to fit the Colson wheels. Not perfect to the thousandth of an inch, but well within typical Team Radicus tolerances :-)
Chris has a new lathe, and it was working just fine! In fact, he hadn't had time himself to use it yet, so we were the first to fire it up, and it was fun!
After hitting the hubs with a countersink (to start the hole), and a couple of drill bits, we had the hubs ready for the shafts. We hope we have a 1/8" broach back at the Build Space ...
The last lathe operation for the day is to bore the bevel gear for the 30lb'er to half an inch - it's metric, and has a 10mm bore at the moment. We didn't realize this was going to be a tough job, but the presence of a keyway messed things up, and we wound up snapping a bit trying to bore this out. We'll have to do a bit of research into a way to accomplish this ...
With profuse thanks to Chris, we jumped back into the BotMobile and headed back to the Build Space, noting along the way that the temperature was over 80°F - eighty degrees in February?! Crazy.
Turning our attention to the smallest 'bot in the fleet, we milled a hole for the weapon motor wires, and drilled mounting holes for the weapon motor in the front of the chassis.
We've also modded the mounting plate a little, and a couple of #2-56 screws and nuts have started the process of mounting the motor to the plate, but we need 3/8" long ones to mount this to the chassis, and we don't have any. Looks like a trip to Grainger is on the cards tomorrow ...
In this photo the motor is actually slightly lower than it will sit on the chassis, but close enough to see that it clears the ground, which is a plus :-)
There's a lot of wiring to be dealt with, so we decided to mill out a bit more of the top part of the chassis - messes up the CamBam+ finish, but at least it we ought to be able to cram everything in now.
We were originally steeling ourselves to have to cut and solder the receiver wires on the speed controllers, but thankfully Kurtis over at FingerTech uses very flexible wire on his TinyESCs, and we were able to stuff the excess into a couple of crannies in the 'bot, and move on.
Next up is mounting the weapon speed controller. We decided to risk the weight and used a small piece of double-sided foam tape to stick it down to the motors at the back of the 'bot, and again we stuffed the receiver lead into space around the battery.
Which brings us to power cables. Because all the wires are quite fine gauge, we decide to just try and solder them all together, and with some electrical tape a zip tie, got them all close enough to hit with the soldering iron in one go. Not pretty, but seems to hold fine.
So we did the same thing with the positive power leads, and did actually remove the zip tie before putting some heatshrink on the end of the leads.
Time for a sanity check. The chassis, plus it's nuts, and a couple of bolts to approximate the missing motor mount nuts and bolts, and we're at 149 grams - looks good to us, but we need to hope that NERC's official scale is close to our's. There is a difference in latitude between Austin, TX, and Harrisburg, PA, but hopefully not enough to cause a couple of grams difference ...
This was a shot after a quick test drive of the 'bot. It is pretty zippy, but fairly easy to control - without the weapon, of course! We'll see tomorrow how it drives with the weapon spinning on the front.
Last shot of the night, and we've milled a small hole on the top of the 'bot to be able to get to the battery connector, so we can disconnect the battery after a match. As long as we can get those #2-56 x 3/8" screws tomorrow this 'bot will be finished tomorrow night!
Tags: build, fairyweight, featherweight, ff2, lathe, pal30, sportsman, tt1
We started off today by paying a visit to Custom Sheet Metal and met Ron, who took our DXF and titanium, and led us back to their waterjet machine, and we got to watch the Waterjet in action. It never occurred to us that there would be white sparks as the titanium was being cut, but then we've only seen polycarbonate being cut before. With a pair of fairyweight-sized blades in hand, we headed back to the Build Space to see how much of a 'bot we could put together today. Hit Back after viewing an image.
You can see one of the blades there on the scale, along with all the other parts we anticipate using, and the news is bad currently - 161 grams - time to put the chassis on a diet! We hogged out a bit more material on Milly, and weight started to drop.
After drilling a few more holes in the bottom chassis section, and hunting down some 1.6mm metric screws we were able to install the drive motors to make sure they fit in the holes we cut for them.
Here's a bit more of the internal layout - the TinyESCs have been calibrated, so we snipped the jumper pins down, and tucked them into their slots, happy they fit. Of course, nothing's soldered yet ...
Now it's time to think about attaching the two halves of the chassis together. These are 1" long #0-80 screws, and we're going to have nuts sunk into the bottom of the chassis. We were going to use six bolts, but screwed up one of the bolt holes, so hopefully four will suffice.
Here we've successfully pressed a titanium blade onto the can of one of our favourite 2204-14T outrunner motors - it's a very snug fit, but we got it on without buckling the can, and added a round of Loctite to help keep it in place.
Here's the underside of the chassis with the #0-80 nuts fitted in 3/16" recesses. You can see at the front of the 'bot that we went a little ... overboard ... hogging out material, and this could cause some issues when it comes to mounting the weapon motor. We've also drilled and tapped the wheel hubs for installation.
The weapon ESC is a little bigger than we had originally thought, so we had to mill out a bit more of the top section to be able to fit it in, but it does fit, which is good!
It's about time to break out the soldering iron, so we need to determine at this point which way to plug the drive ESCs in so that forwards will be forwards. After marking the connections, we heat up the soldering iron and stick the leads to the tabs.
This was taken after a short test drive to verify that we have the wheels installed tightly and the motor connections hooked up right.
Our plan to get over the fact we milled a touch too much off the front of the chassis is to mount a polycarbonate plate to the remnant of the front slope, and mount the weapon motor to that. Unfortunately a 1/4"-thick piece is eight grams - which pushes a bit over the limit.
So we made a 1/8"-thick one, and that puts us just under 150 grams. Given that we'll be shortening wires, etc., we'll come out nicely within the weight limit. Tomorrow night we'll finish the wiring, and the 'bot will be done!
Tags: build, fairyweight, tt1
At this point in time (three weeks til Motorama) we have a finished antweight, a finished beetleweight, and two finished hobyweights. Still in progress are a fairyweight, an antweight, two beetleweights, a featherweight, and a sportsman. We changed our mind on the fairyweight design a couple of weeks ago, and we're not feeling entirely confident that the featherweight will survive it's first hit, but nonetheless we're pressing on! Hit Back after viewing an image.
First order of business is breaking out the table saw and cutting chassis parts for the fairyweight and sportsman. We've cut some UHMW frame rails, and polycarb rails and plates - made quite a mess but they're done.
We also have some UHMW blocks for the two halves of the fairyweight chassis, which we'll set Milly on in just a little bit.
We've slotted the chassis parts for the sportsman, and are testing the fit - looks fine so far. We will need to do a fair bit of drilling though ...
... But not so much tapping - Pete Smith gifted us some Nutstrip at the last Motorama, so we've cut some lengths with a jigsaw, and we're planning on using it to assemble the outer chassis of the sportsman, as UHMW doesn't hold a thread well.
Ta-daa! Kudos to Pete for a handy product - assembling this chassis took about an hour, including the cutting and drilling. Much better than having to tap 36 holes!
Meanwhile Milly is off and running on the fairyweight chassis blocks, using the G-code we got from CamBam+ a while back. Should be interesting to see how it comes out ...
... Quite nicely actually! We need to clean up a little bit with a craft knife, but it's pretty much just as we imagined.
Unlike these frame rails for the sportsman! Geez ... out of six holes, one is in the right spot - the rest ended up all over the place! Not good ... for some reason we had problems seeing the punch marks on the drill press. We're going to have to try that again.
On the other hand, Milly is doing fine cutting the fairyweight chassis down to size. A quick clean-up, flip, and she can do the other side too.
To give us this! They currently weigh 70 grams, but are still half an inch too long, and have another bit of pocketing to go, but they do look how we envisioned the chassis to come together.
Lauren's getting in on the action too, working on her antweight Malicious Mule. She's working on the drive train at the moment, and Toni's letting her do 95% of the work, to get the full building experience :-)
The 'bot is coming together quite nicely, although perhaps not as quickly as Lauren would like, but it'll be up and running, and sparring with Poor Punctuation 2.0 by next weekend.
The final shot of the evening is a close-up of the fairyweight internals - there's an awful lot of wire that's going to need to be trimmed down, but otherwise things are looking good. Next step with this 'bot will be mounting the drive motors and wheels, and drilling holes to bolt the chassis halves together. But for now it's time to go grill some steaks!
Tags: antweight, sportsman, build, mill, fairyweight, pal30, tt1, mm
We spent some time sizing up the fairyweight (150g) opponents for Motorama 2012, and decided that a simple lifter wasn't going to cut it, so we needed something more offensive.Hit Back after viewing an image.
We decided to go with a weaponed 'bot, using as many components as we already had available, so drive motors and TinyESCs, a battery, receiver, and 1.5" tires, and we're already at 81 grams out of 150g allowed in this weight class.
One of the nice things about both fairyweights and antweights is that you can usually sketch a design at 1:1 size. Here we're planning a layout for the components.
Plus said components overlaid on the design. It's a bit messy, but you get the general idea. The wires will all need trimming, etc., and we need to hit the CAD program to find out how much a chassis will weigh to accomodate all these parts.
To try and make things both neater and easier, we taped together the 350mAh 2S LiPo battery and the receiver. Together they make a ni 2" by 1.25" block.
This was our first attempt at a chassis design, but unfortunately came out too heavy, even using UHMW rather than polycarbonate, so we had to rething the layout a bit.
Rather than put the motors outside the battery, how about if we put them behind the battery? There's space on top of the motors for the weapon ESC, and space in front of the motors for the drive ESCs.
This is the top half of the chassis, with pockets for the internal components, and a slope on the front where the weapon motor will be mounted.
And here's the bottom half of the chassis - the hole in the front is simply to save weight. The two halves of the chassis will be bolted together with 1"-long #0-80 screws and nuts.
The weapon motor is a 2204-14T brushless outrunner, the same as we're using in Poor Punctuation 2.0, and the 0.071"-thick titanium blade will be super-glued/expoxied to the outside of the can, again just like we've done in the antweight. The red brick is the 10 gram ESC for the motor.
With the 'bot all assembled, it hopefully will be a fairly tough competitor! Although it has a touch of Little Rat about it - we hope the wheels stay on ...
And of course, some team colours. Although we may end up reversing this, as the two chassis pieces will be milled from black UHMW, so we may just paint the blade and be done with it.
According to the Tentacle Torque Calculator it should be a zippy little thing:
Although weight is cutting it a bit close! There aren't many places we're going to be able to shave off weight, but we'll see what we can do ...
Oh - and I guess we need to come up with a name for this thing too ...
Tags: fairyweight, design, tt1
With the drill press still out of commission, we're falling a little behind in our build schedule, but we found a few other things to be getting on with today, including a non-'bot-related job for a friend at work. Hit Back after viewing an image.
A friend at work caught wind of the fact we have a CNC-equipped mill, and asked whether we could help him with a part he needed fabricating. As we can't get on with a whole lot at the moment, we said sure, and invited him round to the Build Space. The part is a mount for a telescope, and he needed some holes milled for alignment.
It took about an hour to learn about the G2 and G3 codes, and eventually had a G-code script written to mill the three holes. There were a number of firsts - for us - in this simple project, including actually milling all the way through a 3/4" piece of aluminium!
Et voila! In fact, David even paid us for it :-) Good thing too, because we were about to take a hit to the wallet ...
We'd received a call from a machine shop in South Austin that we'd contracted to fix up a few parts for us we couldn't manage by ourselves. Here's the weapon for Didactic Duelist 1.5 all MIG-welded up.
And a couple of parts for the hobbyweight Nihilistic Naysayer 2.0, namely the drum on the left, which had been bored to 1/2" to fit the endcaps, and the rear walls on the right, cut from 4" pipe. Unfortunately the bill for these parts wound up being double the original telephone estimate, so we weren't real thrilled about that, but the work was good.
Here's one of the endcaps in place, although we can't drill and tap it at the moment - hmph!
Same deal with the rear wall ... we sure hope one of the 2L V-belts we ordered from McMaster will fit the drill press when they arrive on Tuesday!
With the exception of a few bolts, we're at 11lb 2.4oz out of the 12lb limit, so we have plenty of weight free on the 'bot we can invest in securing the teeth to the drum.
Turning our attention elsewhere, and we're following some advice from the NERC Forum to switch the output on the weapon motors to decrease the leverage on them and their mounts. Here's one of the weapon motors disassembled.
And we used the arbor press to push the shaft through to the other end of the motor can. This took more force than we would have thought - the shaft is a pretty tight fit in the can, but that's a good thing!
We added a couple of new flats to the shaft for the setscrew and collar. We can reuse the flat already on there from the shaft collar for attaching our pinion gear later.
And we're halfway done. The motor on the left is the adjusted one. We just need to follow the same procedure for the one on the right. Those magnets are really very strong! To reassemble the motor we just put the can in the vicinity of the windings, and everything jumped into place!
And finally two adjusted motors with their mounts attached. We need to add spacers for the pinion gears, and re-attach them to the walls, but that's a task for another day.
Last photo of the day, and it's a Pile-o-Parts we just happen to have sitting around the Build Space ... we wonder if we could make anything with these ...
Tags: mill, build, beetleweight, dd1, hobbyweight, nn2, fairyweight, ff2
Despite trying a number of V-belts from Grainger, we still hadn't found a decent replacement for the drill press, so we had to find other things to work on this weekend. We do have a lot of drilling and countersinking to do, and we're waiting for more parts to show up, so we decided to tackle the things we could actually finish without the drill press. Hit Back after viewing an image.
We started out with some 3/4" UHMW blocks loaded into Milly's vise and a quick G-code script to cut out the wheel holes. We did three blocks, just to be on the safe side.
Another G-code script later, and we had cut the lip in the other side of the block for the top plates. Unfortunately we were down to two blocks at this point, because of a mistake mixing X for Y, and ruining a piece.
Here we've been scribbling to determine the paths for the half-inch end mill for the next two G-code scripts to cut out the insides of the chassis.
The outsides were easy. We had issues a while back trying to cut the whole block because the UHMW flexes in the vise, so we used aluminium spacers to prevent that from happening this time.
And success! Two fairyweight chassis blocks ready for the internals to be added, and no errant cuts. We still need to cut slots for the arm, so that's out next task.
Et voila! We've cut the slots for the arms, and the waterjetted top plates fit great! We finally have a fairyweight chassis to work with ... just as soon as the drill press is back in business.
We spent an hour trying to get the weapon motors mounted in the antweight, but the #2-56 nuts were too big to fit against the weapon motor can, so we decided to sand them down a bit and try again.
Yay! After fiddling around for quite a while longer we finally had the weapon motors installed, and they look good! We Dremelled the titanium gears out to fit the motors and Super-Glued them to the motors earlier this morning.
Here we've tested the fit with the weapon ring, and life is good, although this isn't quite as good as we had in our mind's eye, because there's the potential for the ring to move out of alignment if the two weapon motors aren't perfectly in sync, so we may have to add the idlers back in to this design.
Here we've milled down the lower UHMW ring by 1/32" and the titanium ring moves pretty smoothly, so hopefully we won't need to add bearings to the UHMW.
Tags: antweight, fairyweight, pp2, mm1, build, mill
This site contains records of our trials and tribulations in building combat robots. So much to learn, and so little time!