Despite trying a number of V-belts from Grainger, we still hadn't found a decent replacement for the drill press, so we had to find other things to work on this weekend. We do have a lot of drilling and countersinking to do, and we're waiting for more parts to show up, so we decided to tackle the things we could actually finish without the drill press. Hit Back after viewing an image.
We started out with some 3/4" UHMW blocks loaded into Milly's vise and a quick G-code script to cut out the wheel holes. We did three blocks, just to be on the safe side.
Another G-code script later, and we had cut the lip in the other side of the block for the top plates. Unfortunately we were down to two blocks at this point, because of a mistake mixing X for Y, and ruining a piece.
Here we've been scribbling to determine the paths for the half-inch end mill for the next two G-code scripts to cut out the insides of the chassis.
The outsides were easy. We had issues a while back trying to cut the whole block because the UHMW flexes in the vise, so we used aluminium spacers to prevent that from happening this time.
And success! Two fairyweight chassis blocks ready for the internals to be added, and no errant cuts. We still need to cut slots for the arm, so that's out next task.
Et voila! We've cut the slots for the arms, and the waterjetted top plates fit great! We finally have a fairyweight chassis to work with ... just as soon as the drill press is back in business.
We spent an hour trying to get the weapon motors mounted in the antweight, but the #2-56 nuts were too big to fit against the weapon motor can, so we decided to sand them down a bit and try again.
Yay! After fiddling around for quite a while longer we finally had the weapon motors installed, and they look good! We Dremelled the titanium gears out to fit the motors and Super-Glued them to the motors earlier this morning.
Here we've tested the fit with the weapon ring, and life is good, although this isn't quite as good as we had in our mind's eye, because there's the potential for the ring to move out of alignment if the two weapon motors aren't perfectly in sync, so we may have to add the idlers back in to this design.
Here we've milled down the lower UHMW ring by 1/32" and the titanium ring moves pretty smoothly, so hopefully we won't need to add bearings to the UHMW.
Tags: antweight, fairyweight, pp2, mm1, build, mill
This is turning into quite a productive week! Having made a solid start on Versatile Villain 0.9 we decided to gather up all the milling we need to do and take care of as much of it as possible. And we heard from the Whyachis that our parts will actually be here Thursday rather than Friday, so that should make Friday a busy day too! Hit Back after viewing an image.
The first order of business is the table saw, though. We need to cut some walls and chassis blocks from our recent McMaster order. We have some 0.75" UHMW chassis blocks for Macchiavelian Malcontent 0.9 and some pieces for its 4-bar lifter. We also cut the UHMW and 6061 walls for the next version of our featherweight.
Speaking of the featherweight, here are the two weapon motors - we need to make mounts for them, and so cut out a couple of pieces of 1/2" polycarbonate. Here you can see we're missing a pinion gear, but it's on order from China.
The next job for the table saw is bevelling the walls for Formidable Fustigator 2.0 which didn't take too long, but it was quite daunting pushing a three-inch piece of aluminium across the blade and pressing it into the guide to try and keep it level (our table saw has a dip next to the blade) - definitely had to rest the fingers after that job, but they're all intact!
Here's a completed motor mount - fairly quick and easy to whip up, and we were actually quite accurate in our drilling, which made a pleasant change ...
And here's the second. We haven't figured out eactly how far the mounting distances are for these spiral bevel gears, but we'll sort that out once we have the pinions on the motors and a shaft for the main gear.
Well now ... what have we here? These are the two DeWalt motors that survived from the first version of the featherweight, and they don't look like the spare we have. We Googled for information about high and low speed, and found Team DaVinci's handy page which informed us that these DeWalts were in low gear - doh! We set about disassembling them and removing the locking ring to get them into high gear. It took a while, because those planetary gearboxes are fiddly, but eventually we got the hang of putting them back together layer by layer.
Speaking of things surviving from the first version - here are some pieces that didn't! We decided to spend a little bit of time going through the parts to see if we could use anything as spares.
One of the motors was good, and we were able to scavenge sufficient gears to build a gearbox for it, so these are all the DeWalt spares we have now - three motor/gearbox/mount combos. [Actually, we have two more, but Scott's going to buy those for his featherweight - Ed]
While we were scavenging we fired up Milly, with a program to cut down the lifter arm for the beetle. We've figured out by trial and error that if we run the spindle at 1500rpm, set a feed rate of 6 inches/minute, and take 1/16"-deep passes we get good results. Sure, it takes a while, but when we can give it to the CNC PC to take care of, the speed doesn't matter too much.
After a while, this is what we ended up with for phase one. Looks pretty good!
Next we set up a program for the holes for the arms. Truthfully, we do have smaller endmills, but it's a hassle to switch them, so we're quite content to keep trucking with the half-inch one.
Et voila! Phase two is complete - just ignore that errant cut on the right - operator error :-O We moved the part along in the vise and moved on to phase three, and pretty soon had a finished part, which we put aside and moved on to the mating part ...
... The Plow. Truthfully we should have trimmed this on the table saw earlier, but we forgot. It took a while to cut the 2" angle leg down to 1.375", but hey: CNC PC!
While Milly was doing her thing we checked out the lifter arm - just like the CAD! :-) We only need to drill a couple of holes in it and it's a finished part.
Meanwhile, upping the weight class to 1000% we decided to do a test layout of the featherweight. The only parts we're missing for the body are the batteries, motor shaft and pulley - oh: and the top and bottom plates, but it's already starting to come together.
After Milly was done creating aluminium sprinkles we checked out her work - the plow has a small pocket to mate with the arm. There was probably a better way of creating it, but for the life of us, we couldn't figure out how to make a rectangular pocket with round endmills. Maybe we should read a couple more books ...
The next (repetative) task on Milly's plate is to cut lips in all the aluminium walls for the 30lb'er. Again, taking 1/16" passes it takes a while but the results are fine, and we went back to the beetle.
A little bit of drilling-and-tapping later and the plow is mounted on the lifter arm. We're still debating whether to countersink those holes for flat-head bolts, but for now we'll stick with buttonheads.
The last shot of the night, with the aluminium wall parts all cut for the top and bottom plates. Tomorrow: cutting lips into the UHMW walls - hopefully just in time for the plates to arrive!
Tags: beetleweight, build, fairyweight, featherweight, ff2, mm1, mill, vv1
With the realization that today begins the third final weekend before Motorama 2011 we brewed up some coffee and headed to the build space. We have a lot of grunt work (drilling and tapping) to be done before we can start assembling anything that looks like a 'bot, so we'd best get to it! Click Back after viewing an image.
We started out by finishing up the bottom bearing for the weapon shaft on Formidable Fustigator 0.9. We drilled mounting and pass-through holes in the block, pressed in the bronze bushing, and tested the fit with the keyed shafting - success!
While we worked down the checklist of things to do, we turned Milly loose on a new block of UHMW with the intention of trying to finish the chassis for the fairyweight. This time we trimmed the block to size first, next cut the wheel holes, and then set Milly off hogging out the inside, hoping this time we were doing things in the right order so we wouldn't end up messing the block up again.
Hm - not so much. Once again we'd managed to compress the block in the vise, leading to flex, and the bottom of the block was milled away. Drat! Although we suddenly had an idea ...
... While test-fitting the top plates, we realized we had plenty of spares, so why not use a couple for the base of the 'bot? We can screw a couple of thing strips of polycarb to the walls, and then bolt the baseplate to it. It would cost us a few grams for the polycarb, but at least we'd have a chassis!
After cleaning up the chassis and finishing the removal of the base, we set in some extra panels, and it looked good! Okay, we can run with that: "Adopt, adapt, improve".
We'd been trying to figure out, too, how to bevel the edges of the walls for the featherweight. We'd tried milling the ends, but we didn't want to ruin parts with dodgy math. We were at the point of contemplating buying a scrollsaw, when it dawned on us that we can mitre with the tablesaw, of course. So we set the blade, and tested it out on an inner leg wall - success!
And in pretty short order we had all the inner walls bevelled. Neat.
We also cut and drilled a weapon motor mount for the featherweight. Took a little while to figure out the spacing (metric) but pretty soon that was another part we could cross off the list.
Still plenty to do, though, in fabricating parts for the 30-pounder ... including tapping the weapon braces. 24 1/4"-20 holes later, and those can now be crossed off as done.
While we had the tablesaw out we figured we'd use it, and trimmed the wheel bearings for the featherweight down to 3 inches across. We also elected to leave out the motor mount walls, as the Team Delta motor mounts had their own bolt holes, and adjusted the omniwheels on the shafts to account for the decreased axle length.
We'll spare you the boring drilling/tapping photos as we turned our attention to the frame parts for the hobbyweight Nihilistic Naysayer 2.0, but we marked them up and started drilling and tapping. This is also where we left off for the night, and will pick back up here tomorrow. Hopefully tomorrow we'll take care of all the tube pieces for the featherweight and hobbyweight, and maybe even assemble some internals for one of the smaller 'bots. Stay tuned - same 'bot time, same 'bot channel!
Tags: build, featherweight, ff1, fairyweight, mm1, mill, nn2, hobbyweight
Direct from the frozen tundra of Dorchester, Wisconsin, comes a box full of win: Whyachi-Waterjetted Parts! There are a few parts yet to come, because - get this - they're being heat treated! Oh yes! But as you can see below we have plenty to be getting on with ... Click Back after viewing an image.
These diminutive pieces are top plates for our 150 gram fairyweight. We could have done them ourselves, but with the small size of the parts and relatively large thickness of our fingers, it was just easier to add them to the batch.
Next we have the chassis and drive walls for one of our three pound beetleweights. The black block is UHMW, with some 6061 top plates, and polycabonate motor and wheel mounts.
Here are the frame parts for our other beetleweight - rear wall (with spare), outer walls (with spares), inner wall, drive and weapon motor mounts, and wheel mounts, along with top and bottom plates.
Stepping up a weight class to the twelve pound hobbyweights, and here's the chassis for the second version of our drumbot. 3/8" 6061 outer walls, and 1/2" polycarbonate internals. We're looking forward to putting this one together, because it should be fairly quick - after all, we're really just putting a new frame around the old internals.
Finally a few parts for our thirty pound featherweight. Above are the two weapon braces from 6061 aluminium, and below are some nylon bearings for the weapon blade. Unforutnately the weapon blade hasn't made it here yet, because it's being heat treated, but should show up next week, along with the top and base plates.
Thanks to Jake at Team Whyachi for the immaculate cutting job!
Tags: gearingup, dd1, ff1, nn2, vv1, mm1, build
Following on from yesterday's CNC fun, we decided to try our hand at writing a G-code program, plus we had lots of other stuff to get done, according to our To Do list. Alas, the day did not entirely go our way, but it was a valuable learning experience, none-the-less. Click Back after viewing an image.
We started the day by doing a little programming ... well ... "coding" would be a better word - G-coding, that is. We wrote our first G-Code program, to mill out a chassis for Macchiavelian Malcontent 0.9 from a chunk of UHMW. It was actually quite straight-forward, seeing as though we really weren't trying to do anything too funky. Once in the Build Space we had to review the code, because where we thought 0,0 was, wasn't where the CNC software and Milly thought zero was, and we realized that the CNC software can't control the mill spindle, but after a few adjustments we were ready to roll!
Pretty cool, huh? Here's the final part. As you can see it's not quite done - we had used an over-sized piece of UHMW, so we'll need to mill it down to size, and we're still getting 'hairy' cuts in the UHMW, but all told that was fun! :-) Our next step is to cut the wheel-holes in the bottom:
Oops! We forgot a decimal point in the G-code program, which is why the mill head went all the way up, and then some - fortunately no harm done! We edited the program and re-ran it, and in a minute we had two wheel-holes. So the final step is to mill the block down to size.
For the second time this morning: Oops! Turns out the vise compressed the chassis, causing it to flex upward, and so the program to trim the depth of the block ended up cutting through the bottom of the chassis. Drat. Oh well, we have more UHMW, and we'll chalk this one up to experience!
Turning our attention to the featherweight, and we're working on the walls some more today. Here we're doing a test weigh-in for all the components we have thus far. 17.8lb, which is pretty close to what we were anticipating, so there's a chance we may be sticking with the DeWalts for drive motors, rather than the Craftsman drill motors that are our backup option.
The front wall for Formidable Fustigator 0.9 needs slots in it for the 1/4" 6061 aluminium weapon braces, and so we went back to Milly. This is what happens when your collect isn't tightly drawn up, apparently! Ugh ... another part ruined.
Before loading our spare piece up, we flipped the bad one over and tried again, just to be sure we weren't doing something completely wrong, but the second time - with a tight collet - the cuts were good, so we put the spare piece in.
Second time through, no problems. Ignore the bottom-right corner of the piece ... we were trying to bevel, and our math wasn't quite right. We're going to ignore it, and soldier on anyhow. We may make a new front wall later in the week as a spare, but the more pressing issue is figuring out a good way to cut material, without resorting to having to buy a bandsaw.
Seeing as though our G-coding is going okay now, we're going to get fancy, and try to mill out a bearing block, which means learning how to mill a circle. Our first few dry runs were a little off - the circle drew properly, but it would always be in the wrong place, so eventually we cheated and used one of the wizards in the CNC software to do it for us:
Hey! Not too shabby! We will need to trim this block to size, drill bolt holes in the four outer pockets, and insert a bearing in the middle pocket, and then we have a bearing block for the base of the weapon shaft on the 30lb'er. At this point, having finally made a part without screwing it up[!] we decided to call it a day and go eat grilled cow. More as the week goes on ...
Tags: build, ff1, featherweight, mill, mm1, fairyweight, cnc
Having finally trimmed down the design for our fairyweight to under the permitted 150 grams (5.3 ounces) we were ready to do a little building and get the smallest member of our Motorama fleet underway. Click Back after viewing an image.
Step one is to cut a 4.5" x 2.75" block of UHMW to be the chassis. The easiest way to do that is with the tablesaw - we ended up with two blocks, because it never hurts to have a spare! We actually cut them roughly an eighth-inch oversize ...
... Because we figured we could trim them using Milly, and get them pretty accurate. Seems like we got some 'left-handed' UHMW though ... when we cut in one direction the cut was smooth, but when we cut in the opposite direction we ended up with 'hair' coming off the plastic. Weird.
Not too shabby! We still haven't hooked up the PC for the CNC option, but without it, we were able to get this side spot on. Now for the other side ...
... Well ... what's two thousandths of an inch between friends? Beats our 'standard' machining tolerance of a quarter-inch :-) That didn't take too long, and now on to the inside of the piece.
After cranking some handles, we'd cut the 1/16" lip for the top plate into the piece, and were starting to mill deeper when it was time to wrap up. We definitely need to get a CNC PC set up toot sweet, a see if it makes this stuff easier. On the plus side we finally learned: "Clockwise is away from the handle"!
Tags: mm1, mill, build, fairyweight
Unfortunately we haven't quite finished all our design work, so we haven't been able to order everything we need in time for this three-day weekend, so we're going to have to amuse ourselves with some general building this weekend. We headed out to the build space to dig out some parts, and to figure out some design issues. Click Back after viewing an image.
One thing on our list is unearthing the DeWalts and omniwheels for Formidable Fustigator 0.9. We last had them installed in a middleweight we didn't get to finishing, which we dug out from behind all our materials, and unbolted the top plate from.
As you can see, there are four DeWalt/omni setups in the 'bot, so hey presto! We have a spare. We're still not 100% sure whether we want to use the DeWalts, or some Craftsman 19.2V drill motor/gearboxes - it'll come down to weight at the end of the build.
Next on our list of things to do is to design a new gearbox for Nihilistic Naysayer 2.0's Handiworks motors. Last time one exploded from a hit, and we want to make them a little tougher. We remembered back to making custom gearboxes for Anaphoric Antagonist 1.6 and it was a fairly simple operation. We took apart the damaged Handiworks from version one and took some measurements.
Part of the reason we haven't finished our design work is because we need to design lifting arms for our fairyweight and a beetle. Starting with the fairyweight Machiavellian Malcontent 0.9 we took some 1/4" balsa and a 1/16" drill bit, and started joining things up with rivets.
The first stab, and we realized that when in the 'down' position, the arm wouldn't be sitting flat on the top of the 'bot, which obviously isn't ideal.
Also, with the arm in the 'up' position it sits over the 'bot, rather than toward the front, or even in front, so we need to rethink this position.
After making the rocker (the shortest piece) a little longer, we used a piece of aluminium to represent the top and bottom of the body, and worked around it to ensure the arm laid flat in the 'down' position.
By moving the pivot points closer to the front of the 'bot for the longer upright, we were able to see more of a forward motion to the movement of the arm, which is what we're looking for.
To finally nail down the sizing and positioning, we cut the balsa to the actual size of the 'bot, and checked the geometry in the 'down' position ...
... And the 'up' position - you can see here that we have a much more forward final position, which is what we were shooting for!
Here we're playing with the micro-servo which will power the arm in the 'bot. It took a while to find both a working receiver and a working BEC to power it - must remember to order a new receiver! The little servo seems to have quite a bit of oomph, so it ought to do fine in powering the arm.
Second verse, same as the first. On to the arm for our second beetleweight for Motorama. We used the rough geometry from the first attempt to pin together the pieces here. With some extra wood representing the size of the body in the middle, the arm looks right in the 'down' position.
And looks pretty good in the 'up' position too. All in all we're happy with these designs, so we recorded the measurements of the pin holes, and went back to the CAD for the two 'bots to work on designing the arms.
Tags: build, design, ff1, featherweight, nn2, hobbyweight, mm1, fairyweight, vv1, beetleweight
Bots | General
This site contains records of our trials and tribulations in building combat robots. So much to learn, and so little time!