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
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
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
Today was officially a Snow Day, with Austin having received a couple of inches of snow overnight - not a common occurrence as you may imagine. Amidst the chaos and devastation [Rolls eyes - Ed] we snuck out and went back to see Chris at Speedster Hobbies to do a little more sawing, and to use his very nice lathe. Granted, Milly is part mill-part lathe, but right now she's set up for milling, and so it was just easier to do the things we needed to do over at Chris's place. Thanks again Chris! Click Back after viewing an image.
First on the bandsaw were the DeWalt keyed shafts for Formidable Fustigator 0.9 to trim them down to size, which hardly took any time at all. You'll note that the bottom shaft is different from the rest - it's not an official Team Delta shaft - it was one we cooked up many years ago, but works fine.
We also re-ran the aluminium tube parts for the featherweight - we had forgotten until we laid the parts out the other night that the lengths of tube were oversized, so it was a pretty quick and painless operation to trim an eighth off each piece. Not shown here are the twelve pieces of 5/16" aluminium round we cut for axles for the two beetleweights.
Moving over to the lathe and we had a couple of things to accomplish. Firstly trimming and boring the beetle axles, which was faily quick and easy, and we're sparing you the photo. Second we needed to cut a well in the two blade caps for the delrin bearings, which is what we're up to here.
Ta-daa. The 3/16" delrin protrudes the required 1/16", and all is well. On to the second one.
One of these days we'll learn that material measurements aren't exact. For example, the nominally 3/16" (0.1875") delrin was actually 0.22" inches thick, so we had to go a little deeper on the wells to make the stack of two blade caps and two delrin washers 1.25" tall, but eventually we did. With profuse thanks to Chris we headed back to the Build Space.
This antweight will be the death of us. In reassembling the chassis we managed to snap off the power leads to one of the drive motors, and had a devil of a job reattaching them. As you can see we made a mess of the back of the tiny Pololu motor trying to attach new leads, and finally called it a night. The weather forecast for tomorrow calls for a high of 56°F, so we're going to bed early and will be taking full advantage of the balmy temperatures and maybe - just maybe - finishing a 'bot!
Tags: beetleweight, build, dd1, featherweight, ff1, lathe, pp1, vv1
Following on from our efforts yesterday, we mega-dosed some vitamin C, wrapped up warm and ventured out to the build space. We had high hopes of making it to wiring up the antweight. You'd think we'd learn by now ... Click Back after viewing an image.
To start out today we wanted to be able to mount the rollers. If you remember from the design there are rollers on the end of each wall for the outer shell to roll on. Due to the circular/arc/chord/impressive-eh? geometry, the walls have a funky length, which translates into a funky position for the rollers. The easy approach is to work from the design, and know that the pieces were waterjetted so are exactly as designed.
Through a combination of the hardened scribe points on the calipers, and some decent drilling we put the holes pretty darned close to where they need to be. We drilled the top and middle through with a 9/16" bit, and tapped the bottom for #6-32. We started wondering whether the spinning shell might cause the screws to unscrew ... should be interesting to find out!
Here we've countersunk the roller holes, and also touched the walls to the belt sander to round them a little. They look kinda ugly, but they'll work!
One other piece we need to fabricate is a mount for the weapon motor. Here we've chopped up some 1/8" polycabonate, and fitted tab A into slot B to make sure it fits okay. Talk about an Ikea-bot!
After come fairly careful marking, punching, and drilling, we wound up with a decent fit to the motor. You may notice that only 50% of the bolt holes have bolts in them - this isn't because we drilled the holes wrong - it's because they're a different thread than the ones that are done, and we accidentally threw away the instructions on mounting the motor, so we have no idea what bolts those were supposed to be, but they didn't come in the box with the motor ...
All right ... looking fairly good, but as you can see in this shot the frame isn't square with the motor installed. We knew this was going to happen, and were planning on Dremel-ing out the frame to accomodate the motor properly.
Interesting result following the Dremel-ing of the wall - the tiny screws that hold the gearbox on the Pololu motor unscrewed themselves! Took a few minutes to take the wheel off the gearbox and remount it, but no harm done.
Once all the Dremel-ing was done, we re-assembled the frame around the motor, and it fit great! Time to move on to something else ...
We never got around to ordering sprockets for Poor Punctuation 0.9 but a scrounge around the Build Space unearthed a couple of #25 sprockets, so we put them in place for fun.
Without the main sprocket you can see we inserted a bronze bushing into our milled UHMW block from yesterday for the main weapon axle. We're also going to have to make a spacer for the weapon motor.
Okay - today's major frustration - cutting a 2.25" piece of 1/8" polycarbonate tube for the weapon shell. We wasted major time today trying to figure out how to cut what we wanted Milly's lathe, before throwing our hands in the air and going old school: jigsaw and clamps!
Except the jigsaw wasn't very accurate, but finally we did get the job roughly done, and so as we were planning on firing up the belt sander to neaten up the part and bring it down to 2.25", we smacked ourselves in the head and realized here was something we could use Milly for. We loaded up and endmill and had at it!
Nice! 2.25" on the dot - thanks Milly! We could now think about assembly, with all the fabrication of parts completed finally. These little 'bots are darned fiddly!
Sanity check: these fifteen ounces are everything except a few bolts, and the teeth for the shell. Well ...
... Oops! Not quite ... we forgot the battery. Hmm ... 1lb and 0.1 ounces without the teeth or screws ... not good. We spent a little while looking over the parts to see where we could shave a bit of weight.
The weapon shaft, sprocket, and spacers we dug out earlier weigh a massive 1.7 ounces. We'll have to look around again and see what we can do to save some weight there!
So one thought is this plastic pulley - much larger tooth count, which will slow the shell, but half the weight of the metal one, leaving weight for teeth and bolts. Of course if we could lay our hands on a smaller plastic sprocket we'll be in even better stead ... time to go check out what SDP/SI has available ...
Tags: build, antweight, pp1, mill, lathe
We've been pretty quiet lately. There are a number of reasons: work, visitors from overseas, work, designing new 'bots, and work. Oh - did we mention work? But we've got a week off coming, and we have big plans!
♪♫ We wish us a Merry Christmas
We wish us a Merry Christmas
We wish us a Merry Christmas
And a Happy Birthday! ♪♫
Back in October we ordered ourselves a ShopMaster Patriot Lathe/Mill combo machine. On December 9th it finally showed up, and we've spent a couple of weeks trying to get it ready to run. The 900-pound machine was quite difficult to handle, and we spend time ready other people's reports of getting their Patriot machines set up to try and prepare ourselves. Click Back after viewing an image.
After waiting all afternoon for delivery some time between noon and 5pm the truck finally showed up at 6:40pm! The delivery driver had some issues unloading, and there was a fleeting moment when I thought the whole crate was going to slide off the lift gate, but we wrangled the crate into the garage without too much effort.
A cursory check of the crate showed that one of the steel runners under the crate had gotten mangled, but otherwise the rest of the package looked pretty good.
We took the ends off the crate and then was able to unbolt the front and back panels, which were bolted to the legs of the stand.
We pulled the wrapping off, and Ta-Daa! A CNC mill/lathe to call our very own. Actually, I think we'll call it "Milly" :-) The legs of the stand were bolted to the table, and were cheap, metric crappy bolts, so we put them off to one side after removing them, planning to replace them with decent 3/8" SAE bolts.
These are the extras that came the order. Live centers, collets, a clamp kit, end mills, and miscellaneous stuff. There were a couple of pieces on back-order, such as the 4-jaw chuck and coolant system, but that's okay. For now we need to work out how to get it on the stand, and how to make it go!
Having ordered a heavy-duty mobile shop base, as recommended by another user, we realized when the Patriot arrived that the newer model is larger than the one the other user had, so the base was too small. We decided to make our own. We took six pieces of 1/2" plywood and started to drill them out.
Sad outlet is sad
Sorry - couldn't resist the LOLCat reference. Bill Tillotson came by and installed a spiffy new 220V circuit for us, as what we had previously thought was a 220V outlet was just a funky-looking 110V outlet. Installing the outlet was a very quick job, no doubt made look easy by many years of practice - Thanks Bill!
Almost done assembling the new base - those are 200lb-rated casters, lockable of course. There's an additional benefit to installing these casters (besides mobility) which will become apparent later ...
And the base is readfy to roll - literally. The upper plywood piece is bolted to the end of the leg where the leveller used to be, and then the casters are bolted through using 1/4-20 bolts and locknuts. Hopefully it will be plenty sturdy!
Time to start the scary part - hoisting the 800lb mill/lathe onto the stand. You can see the swanky CNC connectors on the right there. We picked up a 2-Ton engine hoist from Craig's List, and here we're trying to figure out the best location to put the straps.
The first challenge is that the legs of the hoist don't fit under the steel tray. Even if the one bracket hadn't been mangled, it still wouldn't have fit, so we need to figure out how to raise Milly enough for the hoist to slide under.
Solution: 2x4s. We lifted one side and put a few sections of 2x4 under the bracket, and after clearing some working room on the other side did the same there. It was a little nerve-wracking, putting your arm under an 800lb steel tray, with one of the runners looking as warped as it did, but there were no incidents.
Success! Well ... the second time anyway - the first attempt to lift the unit didn't go well, with it leaning badly to one side - definitely brown-trousers-time. After stopping for a think, we were able to adjust the straps and leveller and get a clean lift on the unit.
From there it was pretty easy to slide the stand in under Milly, but that's thanks to the casters - without them the cross-braces on the legs would have meant that the legs of the hoist wouldn't have fitted under the bench. All we had left to do is bolt together the unit and the stand and put it in place.
Ta-Daa! Here we have Milly in place, and we're pretty damn happy about it! No injuries or damage done, and we're set to have a ton of fun during the Christmas break making chips!
Tags: equipment, gearingup, build, mill, lathe
This site contains records of our trials and tribulations in building combat robots. So much to learn, and so little time!