Almost a third of the intended Motorama 2013 fleet is yet to be completed, and we jump in the BotMobile in five days! Fortunately it's not as grim as it sounds - both the featherweight and hobbyweight aren't actually that far from completion, and the beetle walker is essentially a kit, so fingers crossed that one goes according to plan. Today we'll focus on the featherweight Intrusive Interloper 3.0. Hit Back after viewing an image.
First: to the paint shack!Having picked up a fresh can of matte black, the leg parts fo the beetleweight walker get a healthy dose of spray paint, and are left to dry while we turn our attention to the other end of the weight class spectrum.
We have one drive pod that refuses to run in reverse, so our first task for today is to replace it with the spare. We cut some axle shaft, asembled the gear, wheel, and core, and were ready to wire the pod to match the one being removed.
Here we're in the midst of replacing the defective pod, and it's not as plug'n'play as we were originally intending. Given that this 'bot is about six pounds underweight, the next iteration will have both weight and space for better modularity. Maybe we can come up with a way to use PowerPoles to click a drive pod in for power, rather than have to mess with these ring terminal stacks.
But success!Note the motion blur on the wheels and motors - this pic was taken with the transmitter stick at full throttle; which makes quite a racket too! We didn't notice initially, but the back left wheel is actually rubbing on the cardboard box edge that the 'bot is sitting on - oops!
To help clean up, we pulled out the Dyson mini-vac and got all the shavings out. We also had a drive pod that siezed up at this point - the front right one - turned out the set screw in the collar on the brishless motor had undone itself sufficiently to get embedded in the polycarbonate - oops! Another modification we're going to work into the next iteration is a thin polycarbonate wall seperating the wheel from the gears - this will help keep debris and detritus from the floor getting into the gears.
But all in all it was a success - we could actually run straight, and turn on command. Trushfully, we're not sure how quickly we're going to wear through the 45A durometer wheels, but we have plenty of them, and driving with the left/right on the left stick is weird, but that's what driving practice is for.
With some time left yet this evening we turn our attention to the hobbyweight. This one, too, has a brushless drive train, but the idea was that the motors themselves would be the wheels. One of the motors was damaged at Franklin and we never got around to ordering a spare. Instead we mounted one of the slightly smaller ones we ordered erroneously to go in the wheels. Here we're in the midst of laying out the electronics.
The trick is trying to cram this stuff in in such a way that it makes sense and is easy to maintain. With the smaller LiPo battery versus the LiFePO4 ones we used at Franklin we have more options, but the optimal configuration is eluding us.
Finally we have our final configuration and have started wiring the 'bot up, however time has escaped us, and it's time to wrap up for the evening. Tomorrow morning we'll finish wiring the 'bot, and with any luck get it driving!
Tags: build, beetleweight, Hex1, featherweight, ii3, hobbyweight, nn2
After all the problems we had trying to get the pistol radio working with these speed controllers in Intrusive Interloper 3.0 we're going to take a swing at getting it running with the Spektrum radio instead. If that doesn't work, then we're at a loss as to where to go from there ... Hit Back after viewing an image.
But before we get to troubleshooting, we need to sand off the waterjetting tabs on the parts for the beetleweight walker. Now that we're dealing with them as pieces, not just a sheet of aluminium, the realization kicks in: there are a lot of pieces!
And with the last of the sun, we line all the pieces up for some paint - the blue team on the left will get primer and purple, the rest will get primer and black - the metal hexapod will have the same colour scheme as our acrylic one.
While the primer dries we turn our attention to the featherweight's drive pods. Here we've switched from the pistol radio and receiver to the Spektrum setup, and after messing with end points and throttle curves we have this pod running semi-reliably.
With a close-up you can see why this pod runs so roughly - look at the remainder of the teeth on the pinion gear now that we've had a chance to run this pod in for about five minutes - they're grinding away. But on the plus side, at least it's running now. Guess we were slightly off with our motor mounting holes on this pod - drat.
The next two drive pods have zero issues, however, and with a few minutes of breaking in each, they run smoothly, so we install them into the 'bot. The fourth pod was mostly okay, but again had a couple of moments where it took a bit to get it started, so this pod could be an issue. We're still waiting for UPS to deliver our McMaster order so we can cut an axle for the fifth drive pod and try it out.
With four mostly-functioning drive pods in place we turn our attention to wiring. We're going to cram four 2S 2100mAh LiPo batteries in there, as a 2S2P arrangement for the voltage (14.8V) and longevity.
We've also switched the power switch to the beefier one from the previous version of this 'bot, and have started wiring up the speed controllers. Plenty of ring terminals here! But it makes wiring pretty simple. Hook all the reds together and run a lead to the power switch, then add a couple of PowerPole connectors from the switch for the batteries.
Next hook up all the negative leads from the ESCs to a pair of PowerPoles to make the connection to the batteries - nice and easy, which we like!
Lastly we just have to tuck all the radio equipment (receiver, mixer, Y-cables, and PWM leads) into the space that's left between the switch and the PowerPoles. In theory we could ditch the mixer and use the mixing capability with the Spektrum radio, but in order to ensure that when we want to the 'bot to run straight it goes straight, we put the forward/backward on the elevon axis of the right stick, and put the will use the rudder axis on the left stick for left/right. This is the first time we've ever done this, so it will take some getting used to. With the wiring done it's time to take the 'bot for a test run!
Hmm ... not perfect, if we're being truthful. We purposely weren't gunning it, because the Build Space is a bit too messy for a 30lb'er to be bouncing around in it, but it seems that we have 2.5 working drive pods ... we're going to have to put the fifth one together and replace the pod that barely functions, and investigate the dodgy one that works some of the time, but otherwise hey: it moves!
Tags: build, featherweight, beetleweight, Hex1, ii3
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
After running a few errands, including a trip to the hardware store for some more #6-32 taps, it's time to get to work - specifically on the drive train for Intrusive Interloper 3.0, and whatever other tasks we want to cross off the lists. Hit Back after viewing an image.
We picked up yesterday's mail, and in it was a box from Amazon with our monthly Subscribe 'n' Save coffee, plus these two items. A 16GB micro-SD card and a very small camera to put it in. This video camera will be mounted to the Sportsman for some action-cam footage at Motorama.
Skip forward a ways, and we're done tapping the FingerTech wheels without any more broken taps. Aside from the one drive pod we still need an axle for, we've bolted the gears to the wheel hubs, and installed the wheels to the axles with keystock and the nylon cores. Next up are the speed controllers, after a brief interlude for some test driving.
A quick shot of the 'victim' Steel Stiletto was sparring with - a 30lb box of junk. Let it be known to all 12lb builders: cardboard would not be a good armour material :-)
Here we've started to install the speed controllers. They're stuck to the side wall with foam tape, and lead 'C' will be connected to the yellow motor wire in all cases. Red and black will be connected depending on which side of the 'bot the pod is installed in.
We happened to have the table saw out to make a couple of supports for a cat tree (we have hefty cats) so we took the opportunity to cut a second piece of aluminium angle down to size for a second wedge for the featherweight. It still needs to be drilled, but that shouldn't take too long.
Here we have all five speed controllers mounted in drive pods, so the next step is to break out the transmitter, receiver, and programming card, and get these things configured.
Here we're in the midst of configuring the speed controllers. We have two per side, but we're missing a V-tail mixer, unfortunately, so we're going to have to hit a local hobby shop tomorrow and pick a couple up before we can really get this 'bot wrapped up. Time flies when you're having fun!
Tags: build, featherweight, ii3, ss, hobbyweight
We ran some errands this morning, giving us a later than normal start in the Build Space, but the enthusiasm is high, after finishing the Sportsman yesterday, and we're hoping to keep that going as we finish the featherweight Intrusive Interloper 3.0. We have pretty much everything we need, so let's get to it! Hit Back after viewing an image.
First up, we received a McMaster delivery yesterday, and in it was a bottle of Loctite retaining compound 609. We applied some to the one pinion gear we over-bored slightly, and set the drive pod to one side to let it cure.
Next, we need some axles, so we've broken out the hacksaw and some 1/2" keyed shaft. A bit of elbow grease later and we have four serviceable shafts - we need five, but we're not going to hack up a Team Delta DeWalt shaft just to get a spare - we'll order some more keyed shaft from McMaster for next week. For now, four is enough.
While we have the hacksaw out, we chop up some 1.25" diameter nylon round to act as cores for our fancy FingerTech wheels. Naturally, these are easier to chop up than the steel shaft :-)
Next is a trip to the mini-lathe, as the nylon is oversized, and we need 1.25" proper to fit the wheels, so we throw in a cutting tool, and skim off the excess.
Finally we need to bore the nylon to fit on the axle, but we've hit a size limit on the mini-lathe - we can't fit the 1/2" drill bit in the chuck with these nylon cores, and we don't have a shorter drill bit ...
... But we do have a shorter 1/2" end mill, so we chuck that up and set to it. In minutes we have a set of serviceable wheels cores - hurrah!
They're a bit sloppy, but they work, and we're happy with them. Next we need to look at the other side of the wheel, and figure out what to do with the drive gear. We broke the 1/8" broach a while back, so keying the gears is not currently an option.
So instead we elect to drill and screw the gears to the wheels' aluminium hubs. After drilling the first hole, we put a spare 7/64" drill bit in there to keep the gear in place and drill the second hole. This seems to work just fine.
The wheel hub is tapped for #6-32 screws and the holes in the gear are widened to 9/64" and countersunk. With the addition of a pair of 0.75"-long #6-32 screws we have the gear mated nicely to the wheel.
And here's one installed, with the nylon core inside the wheel, the wheel fixed to the axle with some keystock, and the gear pinned to the wheel and mated to the pinion gear. The whole thing spins nicely by hand, so once we have the rest done, we need to hook up the speed controllers, and apply some juice!
Aaaaand the night comes to a screeching halt as we break a tap in the second wheel - drat! Despite scouring the Build Space thoroughly, it seems we're out of #6-32 taps, so our endevours come to an end for the evening, as all the hardware stores are closed at this point. Grrr ... we were really hoping to get the drive pods installed tonight! Oh well, tomorrow will start with a trip to the hardware store, and then we'll pick up where we're leaving off. Same 'Bot Time. Same 'Bot Channel!
Tags: build, lathe, featherweight, ii3
We knew the moment we woke up this morning that we were finally going to receive our fancy new parts from FingerTech Robotics (despite obsessive refreshing of the USPS tracking page not showing any updates) and we wanted to finish another 'bot tonight. Things had stalled a little in our timeline, although things were getting crossed off the To Do Lists. To the Build Space! Hit Back after viewing an image.
Three TinyESCs (two for Lauren's fairyweight and a spare), two prototype power switches (one for the same fairyweight and one for the beetle Belligerent Battler 1.1), and ten - count 'em - ten custom urethane wheels (two for the hobbyweight drumbot, five for the featherweight brick, and three spares). They're Shore A45 hardness, which is actually softer than Colson wheels, and in theory a bit grippier, so we'll see how they perform. Thanks to Kurtis over at FingerTech for getting these to us!
Here's a test-fit of one of the wheels. They're a larger version of sumo wheels, and as such they're open on one end. It took a while but we figured out what we were going to do: turn the wheel around so the closed end meets the hub of the gear; drill both the gear and wheel hub for four #6-32 bolts to couple them together; order some 1.25" OD plastic from McMaster, and when it gets here, cut some 1" lengths, bore them on the lathe, and insert them into the aluminium hubs. We don't see what can possibly go wrong :-)
Despite our enthusiasm, we're going to have to wait on further featherweight progress, it seems, until the McMaster order shows up on Friday. So let's turn to the Sportsman Palindrome30 instead. The last report we put up on this 'bot received nineteen Facebook Likes as of writing this report - we have no idea who all those people are, but thanks! First up today, we drilled and tapped the weapon motor mounts.
And they came out quite well - we did manage to bore one mounting hole while running a drill bit part-way down to recess the bolt heads, as the part 'jumped' up. Still, pretty good show.
We have a piece of 1/2" outer diameter aluminium round pressed on to one motor shaft, but when we attempted to press the sprocket onto the round, all we achieved was to cause the motor to lock up. After unjamming the motor, we decided to turn down the round a little, so we hooked up the weapon power, turned on the radio and receiver, and flicked the gear switch to activate the weapon motor.
After applying a file to the running weapon motor for a little bit, we were able to push the sprocket on successfully. The other motor had already been successfully installed with round and sprocket.
Although it's not recommended, we're going to be using set screws and a little LocTite blue to secure the sprockets on the aluminium rounds. At this point, we're ready to install the weapon motors in the 'bot and think about coupling them to the weapon axles.
In order to power the weapon motors we're going to need a 4S LiPo battery and some speed controllers. We're using cheap HobbyKing 60A ESCs we had laying around, and a Turnigy battery pack. Remember the goal is to not have to buy anything special for this 'bot.
Zac O'Donnell gave us a great idea for getting the weapon blades pinned - genius in its simplicity: Take a piece of 1/4" keystock, drill a short hole in the end big enough for the roll pin to sit in, then hammer the keystock to seat the pin, because we can't get the hammer close enough to the pin itself. Thanks Zac!
With all the weapon blades pinned, we moved on to the transmission, which is #35 chain. Why is it chain always needs an offset link?! It's been a while since we used a chain breaker, and in the end went back to how we cut #25 chain - Dremel off the top plate - because the chain breaker was leaving us with warped top plates on the next link.
The weapon transmissions are in place, so we now need to move to our least favourite part of 'bot building: wiring. We started by attempting to solder bullet connectors onto the two weapon speed controllers. It did not go well. Despite our best efforts: tinning wires, using the helping hands gadget, etc., we ended up frustrated.
So out come the ring terminals, of course. Here we've installed ring terminals on the two speed controllers, and our next move is to do the same with the weapon motors. We'll need some extension wiring between the motors and ESCs to let us put the ESCs where we want them, but that's not a big deal.
The ring terminals are on the weapon motors, and we begin to wire them up to the power switch. We decided at this point it might be worth testing to make sure we're getting this right. The weapon ESCs don't have a battery eliminator circuit (BEC) in them, so in order to test, we'll need to turn on the drive power too, which has a dedicated BEC on it.
Drat. With some temporary wires in there and the power on, there's too much friction for the weapon axle to spin up. We tried both front and back axles, and they both have the same issue - no doubt because we're using aluminium round in bronze bushings, and the round may be slightly oversized. It's getting late, but we're going to have to do two things when next we build: (1) Finsih the weapon ESC wiring; and (2) disassemble the weapon axles so we can sand down the aluminium axles where they sit in the bushings. The other thought that we had, which may eliminate the issue, but adds time to the equation is to replace the aluminium axles with steel, which are more likely to not be oversized. For now, though, we're going to try the sanding route, and see where we end up. Hopefully with one more productive build session like this evening was, this 'bot will be done!
Tags: build, pal30, sportsman, featherweight, ii3
Having had fun with our new lathe yesterday, we decided to put some effort into our other big 'bot - the Sportsman Palindrome30. We need to get the drive train wrapped up, which means installed and chained up. Then there's the weapon and wiring. After fixing up some work issues, we finally headed out to the Build Space. Hit Back after viewing an image.
In order to get the drive train into place, we need to mount some home-made bearing blocks. Here we've drilled the mounting holes, and also 'countersunk' them with a larger drill bit, as we don't have a countersink with a 3/8" shaft, and the 'bot wouldn't fit on the drill press as is.
As it happened though, we had to take the chassis apart, so yes, we could have countersunk the side walls, but moving on - here we've verified that the total width of the axles and bearings is the requisite 2.75". Time to mount the bearings!
They may be ugly, but they work! It didn't take too long to mount all four outer bearings and Dremel-ish down the bolts. So then the next step is securing the drive sprockets to the axles.
For this we cut four very small pieces of 1/8" keystock with the Dremel-ish, and finagled the tiny pieces into place on the shafts. Everything is looking pretty good at this point, so we moved on to chaining the sprockets together.
Rummaging around, we found some random length of #25 chain, and strung a piece across the first side of the drive train, marked where the connecting link should go, and then ground off the link with the Dremel-ish. A bit more rummaging around turned up a couple of #25 master links, and one side was ready to roll.
Here we are with the first side installed. Next we need to mount the inner bearing on the inner rail before we can get too much further, so it's over to the drill press, which didn't take very long at all. We're getting excited - we might actually be able to get this 'bot moving today!
Another random length of chain being cut to size. The amount of junk we have lying around is pretty astonishing - aside from the black UHMW, we actually haven't bought anything specifically for this 'bot - it's all stuff that we have laying around the build space. Granted, we only have more more Victor 883 speed controller left, but if push comes to shove, we can swap in a BotBitz ESCheap85 to run the DeWalt on - we're not messing with gyros in this 'bot, so the incompatibility won't be a problem.
Ta-daa! The drive train has been assembled. Next we want to add some wiring, batteries, and a receiver, and see if the wheels will spin. There are two power switches because the drive and weapons run at two different voltages - 6S (22.2V) and 4S (14.8V) respectively. We ought to be able to wire up the drive, and not have to make any wiring changes later when it's time to wire up the weapon.
Before wiring, we reassembled the chassis. The 'bot bears a tiny resemblance to its inspiration, but is distinctive enough to stand apart from it. We're happy with it thus far :-)
Time for a quick weight check - with all the parts and pieces piled on, the 'bot weighs a scan 25 pounds even. No worries about making weight here then - just like the featherweight we don't seem to be able to use up the entire allotment this time around.
Success! We didn't take any video, but after plugging a battery into the drive wiring harness the receiver was able to bind to the radio, and we made the wheels work! It took a little bit of channel reversing to get things turning in the proper direction, but after a few minutes of fiddling the 'bot drove under it's own power. Then we lost two wheels. Apparently we're going to need a bit more keystock in those sprockets to keep everything engaged - no matter, that's a pretty easy fix. All told, we're in a good mood, and we're looking forward to wiring up the weapon tomorrow!
We decided to capitalize on our productive spurt, and cut and crimped connectors on all the drive motors for the featherweight Intrusive Interloper 3.0, using the one drive pod we assembled the other night as a reference point.
Finally for tonight, we also put connectors on the remaining speed controllers, so there's one less thing to do when the wheels show up and we can do some final assembly on the drive pods! All in all, a pretty productive day :-)
Tags: build, featherweight, sportsman, ii3, pal30
There are a number of pieces we need to chuck up on a lathe in order to finish the remainder of the fleet, and we feel bad pestering Chris every time we need to make circular operations, so we checked out our lathe-buying options this week. Technically, Milly can lathe things for us, but to convert her from milling to lathing means a pretty big clean-up job, and we don't have the time for that. So we made a purchase ... Hit Back after viewing an image.
Given $100 off, plus a 20% off coupon, we knew what we were going to order, but we didn't know where we were going to put it, so purchase number one (with another 20% off coupon) was a work table. This photo doesn't show the 75 minutes we spent trying to assemble this darned thing, but once it was done, it was rock solid.
This was actually a decent deal price-wise: normally $599, on sale for $499, plus a coupon for 20% off, and the price before tax was $399. We bought the $80 2-year No-
Questions-Asked Warranty, which gave us another $25 off, so for $375 we had a $600 mini lathe with some pretty decent reviews.
After taking the shipping bolts out the bottom of the package, we opened the top of the box, and found a few tools and parts. This seems to be a beefy package - 90lb - so hopefully this is a solid piece of kit.
After pulling out the top packaging we get to the meat of the sandwich: a 7" x 10" mini-lathe. There's still some heft to that box, so we're not risking our backs just yet - we want to make sure everything we payed the [discounted] price for is ready and available.
We've liberated handles, tools, outer chuck jaws, safety guards, rubber feet, and a spare fuse - sounds like we're about ready to roll. We did buy an MT2 drill chuck and a few pieces of miscellaneous tooling when we picked up the lathe, so maybe we can do something productive today.
We originally planned on mounting the lathe to the workbench, but didn't have long enough M6x1 bolts, so we decided to mount the rubber feet to the chip pan, and set that on the new work surface.
Turns out that works fine - the instruction manual suggested we break the lathe in - normally we're sceptical of such moves, but what the hey! We ran the lathe for 60 minutes at varying speeds in High, Low, Forward, Reverse, and every combination thereof. It worked well.
So - to productivity! Here we've just run a #11 drill bit through a pinion gear for the 30lb'er drive train. A #11 drill bit is nominally 0.1910", and our calipers tell us the inner diameter is now 0.1915" so that's some pretty tight performance! Unfortunately still not big enough to press fit on to the 5mm drive motor shafts, so we moved up to a #10 drill bit.
The #10 drill bit took us to 0.1940" inner diameter, and we needed closer to 0.1960" so we then moved up to a #9 drill bit, and that was just a hair too much - this gear could be pushed on to the pinion just by hand, so we're going to have to pick up some Loctite 609 retaining compound for this one, and decided to stick with boring the rest of the gears with the #10 bit, and see how they fair being pressed on to the shaft.
The operation went very well! Using a single washer on top of the gear gave us the right spacing when pressing the gear on to the shaft to align with the wheel gear, and we were extremely happy at this point. So happy, we decided to up the ante ...
... and worked on the wheel gears, enlarging the bore in 1/32" increments from 3/8" to 1/2".
The finaly pass with the 1/2" drill bit was tricky - it was riiiiight at the length we could push the tailstock back, but we persevered, and our patience was rewarded.
Here we have it: five wheel gears with 1/2" bored sitting nicely on the keyed shaft - the next step is to cut the keyed shaft to length, and then wait for the wheels to arrive from our friend at FingerTech Robotics. It's going to be a long wait, according to Canada Post tracking :-(
As you can see here, things line up very nicely. Despite the assault from the arbor press, the motor spins freely, and the teeth are well meshed between the gears. We can hardly wait to see these drive pods in operation! All in all, a good day's work :-)
Tags: gearingup, build, featherweight, ii3, lathe
We knew we weren't going to have a whole lot of time this evening, but we did want to get at least one speed controller installed in a drive pod for the 30lb'er, just to verify they'd fit. Plus we got a package in the mail that needed investigating ... Hit Back after viewing an image.
And here it is: an Arduino starter kit from Pololu, put together by SparkFun. All we had time for today was to verify the contents.
We have a number of resistors, presumably for the LEDs, a stretch guage, a potentiometer, a buzzer, a transistor, another USB cable, a small breadboard, a bunch of wires, and the Aduino Uno R3 board itself. We're looking forward to hooking that up and playing with it in the very near future, but on to drive trains!
First question: does the ESC physically fit inside the drive pod? Answer: yes - just. We knew it had capacitors hanging off it, and they fit nicely in the wire entry/exit hole. We will need to trim a bunch of wire off both the motor and the ESC, but at least they do indeed fit, and with just enough clearance too.
First task with these speed controllers is to ditch the on/off switch - these puppies do us no good switched off! We broke out the soldering iron, and put a small blob of solder across the switch pins on all five speed controllers. In hindsight, we should have pulled out the spare for Nihilistic Naysayer 2.5 and done that one too, but oh well.
Second task is securing the PWM cable and the fan power cable. A thin-ish smear of hot glue does the job nicely. Having prepped them, it's time to sort out the wiring.
The basic idea here is repeatability, but with a twist. We can't solder the wires together, because to reverse the motor for left/right drive pod placement of the spare we need to be able to flip two of the three connections. So we decided to go with ring terminals - surprise! The yellow motor cable is the shortest and will always be connected to lead C from the ESC. The red and black motor wires are left longer, and will be the pair swapped if necessary to reverse motor direction. Having established a reference model, when we next come back to work on the featherweight's drive train we can move a little quicker with the remaining four ESCs.
Tags: build, featherweight, ii3, arduino
We have a bonus build day today, as our day job closes to observe Martin Luther King day, so it's out to the Build Space to see if we can cross some more items off the To Do Lists. We're going to focus on the two biggest 'bots today - the featherweight Intrusive Interloper 3.0 and the Sportsman Palindrome30. We're a bit stuck on the drive train for the Sportsman, and pretty much out of parts for the featherweight, but we'll see what we can do! Hit Back after viewing an image.
Ah, the mighty To Do Lists ... they keep us on track, and provide much enjoyment when it comes time to cross something off. If you look closely, you'll see there's actually a couple of items for 'completed' 'bots, but we save small tasks like that for weeknight build sessions so we can maximize the daylight time for marking, drilling, etc. For some reason, it just seems to come out more accurate in sunlight ...
Speaking of accurate drilling - it's time to do some. Using our CAD model of the featherweight, and knowing the mounting holes for the drive motors are 25mm apart, we marked and drilling one of the drive pods and test-mounted the motor. Came out well.
Well enough that we went ahead and drilled and mounted all the drive motors. The all seem to be pretty darn accurate, so that's good. Now we wait for gears, wheels, and speed controllers.
Some more accurate drilling later and we can actually mount the drive motors for the Lauren's fairweight - they're a bit cramped, but they fit, so that's good. We have a battery and a receiver for this 'bot, and we just need a couple of speed controllers.
Turning our attention to the Sportsman, and one area we've been stumped is the drive train - never exactly our speciality by any means, but without a decent lathe (sorry Milly) or even a broach any more, we can't make new ones to fit these 6"x1.5" Colson wheels. Instead we decided to get creative. We started with the pre-made hubs used in the last dismal version of Steel Stiletto. They're not long enough to go through the entire bore, but they're a good start.
Then we broke out our parts bins, and started looking for things that would help fill up the bore in the wheels, yet accomodate a keyed 1/2" shaft. We were willing to take any combination of bearings, bushings, washers, and shaft collars that would work!
While we were fiddling around trying different combinations of the above, UPS dropped off a package - gears for the featherweight! And a bonus LED light - handy. In the foreground are the 12-tooth 32 pitch steel gears; they have a 3/16" (0.1875") bore, and the drive motors have a 5mm (0.1969") shaft, so we're going to need to figure out how to enlarge the bore to fit the motors. In the background we have the 54-tooth gears that drive the wheels, and their 3/8" bore will need to be enlarged to a half an inch at some point. When the wheels arrive, we'll decide whether to go get the gears broached for a keyway, or whether we want to mount the gears to the wheels themselves with bolts.
Back to the Sportsman, and we need to fix the saw blades to the shafts and cut holes in the front and rear walls for the weapon chain. To that end we removed the front wall from the 'bot to make it easier to work with. We never created a CAD model for this 'bot, just started winging it a while back, and made a few poor decisions along the way, which is why the weapon axle mounts overlap the bolts that secure the front wall to the inner rails - oops.
We broke out the Dremel-ish and ground flats into the aluminium axle to make drilling the pin holes easier. It was a bit cramped in the outer spaces, but still relatively trivial to do.
In a moment of inspiration, we figured out the mounting solution for the Colson wheels! They have a 1-3/16" bore diameter, and in addition to the bits of axle core we retrieved from the former hobbyweight, these 1/2" shaft collars have an outer diameter of 1-1/8" so with the addition of a circumference-worth of double-sided sticky foam tape, they pressed in nicely! We're going to pin them through the tire too, but we have a solution!
Ta-daa! With some nylon washers, we're able to run chain pretty smoothly on the sprocket, and the whole solution fits the two inches across that we have between the inner and outer rails. There's still pinning to be done, and we need to put a tiny piece of keystock in each of the sprockets.
But hey - we have a workable solution, and quickly have all four wheels mounted on makeshift hubs - they're also much less wobbly than the ones we previously had in Steel Stiletto, so that's a bonus! Mounting the tires had been a major sticking point, so we're really happy to have this problem licked :-)
Back to the weapon assembly, and here we've drilled the pin holes for the 1/8" roll pins, but then realized that the one inch long pins we have we going to be far too awkward to hammer in, as there's only an eighth-inch of clearance beside the saw blades. We're going to have to order some longer pins and then Dremel-ish them off after inserting them.
While we had the walls off, it was an opportune time to cut holes for the weapon chain. We started by drilling some 3/8" holes in the corners, then broke out the jigsaw to finish them off. Fairly quick and painless to do.
So here's where we're wrapping up for tonight - we need longer pins for the weapon array, then those will be done. We need to drill the side walls for the drive bearing blocks, and install the drive train. We need to drill and tap the weapon motor mounts, and install those. Then it's a matter of wiring the 'bot up, and taking it for a test drive. With any luck we'll finally have this 'bot done by next weekend!
Tags: build, sportsman, featherweight, ii3, 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
Yesterday we spent the entire day making chassis components for the featherweight rebuild Intrusive Interloper 3.0. Today we're aiming to put tab A into slot B many times over and get these pieces assembled. Hit Back after viewing an image.
A quick run-down of where we're at: the front, rear, and side walls have been milled but need drilling and tapping; most of the polycarbonate drive pod parts have been drilled and tapped for assembly, but we still need to put in mounting holes. So with that - let's get to work!
Two hours elapsed between the last photo and this one, and we want to see progress, dammit! So we assembled the first drive pod, and mounted it to the baseplate.
As you can see here, our drilling has been pretty accurate, and all seven bottom mount bolts went into place, which we're very pleased with.
We also slid the keyed shaft in with no issues. This is a 12" length of shaft, which we need to cut into four pieces at some point, and then rustle up a fifth piece from somewhere, but we have plenty of odds and ends in the Build Space. One down, three and a spare to go.
Half an hour later and we've drilled and tapped enough to be able to install the second drive pod to the base plate. Again, the shaft inserts cleanly, so we're good to go.
As we tried to assemble the third pod, we realized we were out of bearings, so it was time to pull out the carcass of the previous version and extract the bearings from it. Fortunately they were fairly easy to remove.
With a handful of liberated bearings, and another half an hour of drilling and tapping, and we have the third drive pod installed, and tested with the shaft. This is starting to look like a 'bot ...
Twenty minutes later, and this is what the underside of the 'bot looks like: twenty-eight - count 'em - twenty-eight bolts all successfully installed in four drive pods. That's pretty much unprecendented accuracy - yay!
Now that all the drive pods are installed it's time to focus on the walls. The walls themselves fit together quite well, and the lip for the plates are reasonably accurate.
To ensure that when all buttoned up things will fit, we applied some pressure with bar clamps to make sure things fit okay, and they definitely do, so onward, with more drilling and tapping!
As the drilling and tapping progresses, we take breaks every now and then, because the old wrist gets tired doncha know? During one of the breaks we hunted down a pair of 2S 2100mAh LiPo packs from our stash, and they fit the battery compartment just fine, so we have juice for the 'bot - including spares.
A bunch of time passes in a TapMagic-fueled haze, until eventually we reach this point with the underside of the 'bot: seven of the bolt holes in the walls failed to line up properly, although eleven did, so that's a better than 60% success rate - that's more like Team Radicus accuracy :-) We'll enlarge those bolt holes at a later time.
We faired better with the bolt holes for the walls on the top of the 'bot, with fifteen lining up and only three not, but worse with the drive pods, missing a total of six bolts there, so another batch of bolt holes to be widened at a later time, but still not bad at all.
Comparing version three with version two: the new edition is much more compact - nearly two inches smaller in length and width, and a half-inch shorter in height. Significantly more bolts though :-)
Our last photo of this marathon day: checking the weight of what we currently have available. The chassis, empty drive pods, front wedge, and battery packs weigh in at 17 pounds even. All there is to add to this 'bot are four motors, four speed controllers, four sets of gears, four wheels and axles, a power switch, a receiver, and a gyro. This is going to be a severely underweight 'bot! Tonight we dream of bolts ...
Tags: build, featherweight, ii3
The one 'bot with the largest amount of construction to do is our thirty pounder Intrusive Interloper 3.0. It has a whole new chassis, and a bunch of discrete drive pods, although at the moment these are all sitting as a pile o' parts in a box, so we decide to get busy! Hit Back after viewing an image.
As there's not really anything to do on the top and bottom plates, we set them outside and hit them with a coat of primer, followed by Team Radicus purple, and finally a clear top coat in quick succession. Fortunately today has warmed up, unlike the last few days, so these parts dry fairly quickly.
The outer rails need a lip cut in them for the afore-mentioned top and bottom plates, so we set Milly in motion working on them. While she's doing her thing, we can turn our attention to ...
... The drive pods. There are five of them, including a spare, and plenty of drilling, tapping, and countersinking to do to get them assembled, so we decide to start with one, as a demo piece.
And it comes out very nicely! The keyed shaft slides right into place, and even turns freely in the bearings - bonus! Obviously this pod isn't finished: it still needs to be drilled and tapped for mounting to the top and bottom plates, and it needs a few things like, oh, a motor, and gears, and a wheel, and a speed controller, but it does look awfully like the CAD, so we're happy, and decide to move forward with the remaining four pods.
Meanwhile, Milly is going great guns cutting the plate lips. Despite drilling one hole off, and and breaking a tap in the other, we've decided we're going to use the two side rails anyhow, rather than remake them, because there are going to be so many bolts in this 'bot, one missing each from the front and rear aren't likely to be an issue.
Speaking of bolts, here are the five piles for just the drive pods. Twelve 1/4"-20 by 1" flatheads for assembly of the pods, and ten 1/4"-20 by 1/2" buttonheads. Each. Yup - each! 102 bolts for the drive pods, and a further forty for the chassis rails. Good thing we have a large stockpile ...
Excuse the mess, but we're busy here! End-drilling the polycarbonate for these pods is pretty simple at this point - we've been doing it ever since the Bad Grammar days. So these don't take too long to whip through.
We'll spare you the tapping photos, but there's a ton of it to do. Eventually we're at a point where we can install the very first chassis component onto the baseplate: the battery lid stand-off! Well, not very exciting, but hey - assembly has commenced!
Here's the access panel installed to ... well ... the stand-off. Milly is still working on the outer rails. But if all our drilled and tapped holes line up as well as the ones in this piece, this will be a breeze to put together!
Speaking of Milly, she doesn't quite have the capacity to put a slot in a 14" length of aluminium bar, so we flip it around, re-jig the program, and let her finish up the last couple of inches on each end. Speaking of finishing up, we've done a lot today, and it's getting pretty cold, so it's time for us to wrap up (no pun intended) and head indoors. Join us again tomorrow, where we could see some actual chassis construction - Same 'Bot Time, Same 'Bot Channel!
Tags: build, featherweight, ii3, mill
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
We had a few spare hours tonight, so we decided to hit the Build Space and do a little more on the antweight and featherweight rammers. There was some milling, drilling, and tapping to be done, but that sounded like a pretty good use of a Sunday. Hit Back after viewing an image.
First up we put the vise back on Milly and decided to edge the walls for Malicious Mule - they need to have a 1/16" lip, and it's pretty easy to get this aligned and cut for an eighth-inch top plate.
Meanwhile, we looked back at the CAD for Intrusive Interloper 3.0 and realized that we need to cut the outer rails shorter so they can be pocketed into the front and rear walls. Time to head back to the table saw.
Finaly we have some pieces for the antweight, including the front and rear rails plus the side rails, and a spare should tapping go astray ...
Having sorted out the length discrepancy with the table saw, it was time to get to pocketing, and so we added the 3/4" 6061 aluminium to the list of stuff Milly has to deal with.
After some judicious miling we had a decent boundary established for the front and end pieces, but there's work to be done on the side pieces.
Wow. That hasn't happened in some time - we've managed to break a 1/4-20" tap in some aluminium which hasn't happened in years. Time to buy a new tap, and get back to it, but in the meanwhile we have some stuff to do.
Finally we mock up the featherweight chassis to get an idea of a space it will need once completed. Everything will fit just fine, and we might be able to go to two packs in parallel.
Tags: build, featherweight, antweight, mm, ii3, mill
We had fun with Intrusive Interloper 2.0 at NERC's Franklin Cup 2012, making it to the final against Tetanus, but failing to overcome that beast, ending up sitting forlorn in the arena, immobile. With that in mind, we wanted to beef up the drive train in this next version, preferably without spending $200 per wheel in motors and speed controllers. Hit Back after viewing an image.
We've decided to make the drive train modular, so that if needed we can swap in a complete wheel/motor/ESC set, plug in the ESC, and have it ready to roll. With that in mind, here is the frame for the drive pod, made from half-inch polycarbonate.
Here's where the oomph comes from: a G25 610kv brushless outrunner motor for $25. There's a 12-tooth gear pushed on to the 5mm shaft, which mates to a 56-tooth gear, giving a 4.666:1 reduction.
Here's the axle assembly: a half-inch shaft, with bushings on either end, and the wheel is a custom 40A durometer 2.5" FingerTech Robotics sumo wheel. We used 40A at the Franklin Cup, and while it was grippy, it did wear faster than the traditional 65A Colson tire, so we'll need to remember to pack a few spares.
Here's the drive pod assembly all together. The green block is a 60A reversible car brushless ESC, again about $25, so throwing in the gears, wheels, and polycarbonate, each drive pod is around $100 to build - much more reasonable than a DeWalt and a Victor 883!
The chassis for Intrusive Interloper 3.0 is a slightly modified version of the previous one. The frame is entirely 3/4" 6061 aluminium, with a 3/8" thick front wedge. The top and bottom plates are 0.071" titanium. Excluding the wedge, the chassis is 14" wide, 12.25" long, and 2" tall.
Here's the chassis with four drive pods installed. The pods are designed to be installable in any place, and just switching a pair of wires from the ESC to motor to set the direction.
The top and bottom plates both have mounting holes for the chassis and all four drive pods. That means it takes 46 bolts to remove the top plate - that's a few too many to be able to get the battery out for charging, so we're cutting a battery access panel into the top plate - three bolts is much more reasonable!
The battery is a 4S 3Ah lithium polymer pack, and should provide sufficient current by itself to power all four motors. On the other side of the polycarbonate stand is where the power switch, receiver, and gyro go.
Here we have all the internal components in place. There is a quarter-inch between the left and right drive pods, to allow for the ESC power and PWM signal wires to make it out to the middle of the 'bot. Although we haven't factored in the weight of the hundred or so bolts there will be in this 'bot, we're not worried about weight:
Here's the obligatory "Team Colours" render - note the purple wheels - we've about talked Kurtis over at FingerTech to do a custom colour for us ;-)
Tags: design, featherweight, ii3
We have a pretty busy build schedule between now and January, intending to upgrade most of the fleet in preparation for Motorama 2013. We do have some parts, but the bulk of the waterjetted parts are still in Wisconsin, so we're working with what we have on hand. Hit Back after viewing an image.
First up, a few pounds of aluminium from Speedy Metals, specifically the chassis for a redesigned Intrusive Interloper 3.0 - three-quarter inch front, rear, and side walls, and a pair of three-eighths thick angle for the front wedge. We've slimmed down the design so the body is only two inches high.
The aluminium from Speedy Metals was cut slightly oversized, so we ran it through the table saw to trim it to length. The front and rear walls, along with the angles, are 14" long, and the side walls are 12" long, but will be recessed a quarter-inch into the front and rear walls. As we were working with the table saw we decided to chop up some 5" lengths of quarter-inch thick 6061 bar to be the chassis for Lauren's antweight, also on it's third version.
Here's the basic layout of version three of Malicious Mule, with 1.5" Lite Flite wheels, receiver, batteries, and gyro. The bar, however, is 1.25" tall, and we needed one inch so ...
... It's over to Milly to trim the stock down. While the vise is in place we'll also work on slotting the front and rear walls for the thirty-pounder too.
Ouch! Well, we've bled on the featherwight, so the 'Bot Building Gods should be appeased - hopefully the sacrifice pleases them. That'll teach us to run a hand over the underside of a freshly drilled hole - stop and check for swarf first!
Here's where we're going to wrap up for the day - the front and rear walls for the featherweight have been drilled and countersunk for the chassis bolts - we'll still need to slot them, and drill holes for mounting the wedge too, but that's another build report.
Tags: build, mill, antweight, featherweight, mm, ii3
Okay - we need to "Make it work!" as Tim Gunn would say. On the agenda for today, we want to get Intrusive Interloper 2.0 running reliably; get Steel Stiletto running reliably; try to finish Malicious Mule; and try to finish Belligerent Battler 0.9. Sounds like a lot to do, so we'd better get started! Hit Back after viewing an image.
Having picked up some Y-cables from the local hobby store we set about re-wiring Intrusive Interloper 2.0 with four Victor 883 speed controllers, one per DeWalt. The wiring was a [messy] piece of cake, but it turns out two of the Victors were bad. Here we're swapping in spares.
Argh! Of our two spare Victors, one of those was also bad, so now we're in a bind. We have three of the four motors hooked up, and one lame duck.
Ouch - $600 of blown electronics sitting right there. We were stumped. We scoured all our parts bins, and even tried wiring in one of the hacked TZ85As, but that didn't work either. We weren't convinced we could get a speed controller in time even if we ordered one. This was not a pleasant feeling.
Suddenly inspiration struck - and we pulled out the pile o' parts for the Sportsman we began building for Motorama 2012, and struck gold! There was a Victor 883 mounted to the baseplate! Fingers crossed it works ...
And it did! Hurrah! We now have Intrusive Interloper 2.0 running like a champ. Shame we never got the gyro to work properly, but no matter, we actually feel like we have a 'bot that's working properly. Even if we accomplish nothing else between now and next weekend we have a featherweight and a hobbyweight - more than enough reason to fly to Philly :-)
Steel Stiletto is working fairly well on the new battery pack, but certainly has some control issues, predominantly due to the kludged-together drive train. With a bit more time we'd re-make the hubs for the wheels, but for now we're going to just try 'breaking them in' and see if we can get the 'bot to be a little more controllable. Again, another instance where having a working gyro would be useful, but oh well.
Moving on, we go from the largest 'bot to the smallest: Malicious Mule. Here we've pressed bushings into the outer rails, and we're about to fix the wheels to the axles.
A quick weight check shows that there's no worries in terms of weight - the scale reads 14.6 ounces, so we don't have to sweat that aspect of the 'bot - we just need to finish assembling it.
Here we've bored the wheel hubs out to a quarter inch and pressed in aluminium spacers which will be our axles. The hubs will be pinned to the spacers, and the spacers have been drilled and tapped for a screw to hold them to the Pololu motor shafts.
Here we have the first two axle/hub combos installed. We currently only have three of the four wheels we need for the 'bot, and we're waiting on the Robot Marketplace to make good on the last one. Hopefully the wheel will show up before we get on a plane on Friday ...
All in all we're in pretty good shape with this antweight. All we need to do is tame the wiring and put the fourth wheel on. We did take it for a quick test drive, and the speed is markedly improved over the previous version!
That's practically three 'bots running, so let's go for a fourth. Here's our To Do list for the beetleweight Beligerent Battler 0.9, and although it seems like a fair bit, there's not really that much to do, so we hop to it!
Here's a pair of top and bottom plates quickly cut out on the table saw. We're going to use the jigsaw to cut the wheel holes, give them a lick of paint, and then we can install them.
We've also trimmed down the front wall to allow the timing belts to pass from the weapon motors to the beater. We basically cut 3/8" off each end and installed spacers. We've also installed the weapon motor mounts.
As it's getting late we want to get all the noisy work out of the way quickly, lest we incur the wrath of the HOA, so we quickly cut and sand the wheel holes in the top and bottom plates.
We ground a flat on the weapon motor shafts, and installed the timing pulleys with screws and a dab of Loctite. Hopefully they'll spin - we're not worried about them coming off, because there's nowhere for them to go in the 'bot, it's more making sure they stay engaged on the motors.
And here they are installed! We're contemplating milling a shallow pocket in the side walls, as the pulleys do rub a tiny bit, but we'll see how it goes when we hook everything up and give the weapon a test run.
Here we've installed the baseplate, and right now we'd have to say things are looking pretty good! We're not going to get this 'bot finished tonight, but hopefully tomorrow evening we can do the wiring, and barring any major issues, ought to be able to wrap up the three-pounder tomorrow.
So then the decision will be what do we do next? Both the antweight Persistent Pugilist 0.9 and hobbyweight Nihilistic Naysayer 2.0 have a bunch of work to be done to get them ready. We're thinking we forego the antweight and concentrate on the 12lb'er, because that weight class at Franklin only has five entrants, which could help our chances of winning something, versus the dozen or so antweight entries. Sounds like a plan!
Tags: build, bb1, beetleweight, antweight, mm, featherweight, ii2
We got a late start today, having to spend the morning and first part of the afternoon sorting out a client, but we quickly got into the swing of it, desperately wanting to get at least one "Presenting" post out today, as we're short four working 'bots with exactly one week to go. Hit Back after viewing an image.
After running the 'bot with the second new 9.9V A123 battery pack we're happy with the current state of the rebuilt Steel Stiletto, so we're going to call this 'bot done! Presenting the rebuilt Steel Stiletto!
Moving on, we're done with the re-wire of our 30-pounder Intrusive Interloper 2.0, having wired in four Victor 883s but we're short a couple of Y-cables for the drive ESCs, so we can't test-drive this configuration just yet - we've made a note to hit our local hobby shop tomorrow so we can scratch this 'bot off the list.
It's not stretching the truth to say we had some "issues" tapping the 1/4" 6061 aluminium rails for Malicious Mule, so here's a fresh set from Team Whyachi which have been drilled and tapped without incident, ready for a fresh coat of paint and installation.
Here we've begun assembly for Malicious Mule, with the 10:1 HP Pololu drive motors mounted to the inner rails, and the base plate attached so we can start looking at the internal components.
Here's a test layout for the battery pack, receiver, and gyro, for the 'bot Malicious Mule. Two things strike us imediately after taking this photo:
1) There's not as much space inside this 'bot as our CAD suggested; and
2)We've had zero luck thus far in the build season for gyros, so we're not expecting this to go well.
It's very rare that we feel good about soldering something, but we think we did a pretty good job putting leads on the 10:1 HP Pololu motors, and so the next task is to connect the ESCs.
To reiterate: our soldering skils are not that good. It took over an hour to go from the previous photo of leads on motors to this pic of motors connected to speed controllers, but eventually we got there.
The final challenge of the night we wanted to take on, was getting the receiver to bind with the radio. We plugged things in, unpluged them, plugged half of them in, and eventually got the receiver to bind. Next was calibratintg the ESCs, which also took a while, including swaping the V-tail mixer. But finally we had it done. Tomorrow all we have to do is sort out the drive axles, and we have another "Presenting"' post on our hands, assuming we don't try to use the gyro ...
Tags: build, hobbyweight, ss, featherweight, ii2, antweight, mm
This site contains records of our trials and tribulations in building combat robots. So much to learn, and so little time!