A Double Dose of Servos

by Toni 1/28/2013 13:28

Finally! Two packages have been dropped off by USPS - both containing servos. One came from Hong Kong, and the other from Washington state. Let's check them out ... Hit Back after viewing an image.

The Hong Kong package contains 22 metal geared servos that we're going to put in our Hexy Kit tonight. Then we're going to load up the kit so it weighs a grand total of six pounds, and then we're going to see if it will walk. The idea here is that if it can move six pounds with these servos (rated for 2.2kg-cm of torque) then we can build the aluminium combat version of the kit with them, and keep the same leg design.

If it turns out that the replacement servos can't cut it, we'll need to trade up to heftier servos. For comparison the original metal gear servo is on the left. Next to it is a larger servo, also with metal gears, rated for 3.0kg-cm of torque - this would be our first choice replacement, as it's the smallest of the three options. Basically what we'll do is, knowing that the little blue servos have 2.2kg-cm of torque, we'll see at what weight they can move the kit, and then factor the needed torque for six pounds from there. For example, if they can move the kit at four pounds, we'll know that to move six pounds we'll need about 3kg-cm of torque, and so the next size up servo will work. If the little blue servos can only move three pounds, we'll need to step up again: the third servo is rated for over 6kg-cm of torque, and the fourth one is rated for 8kg-cm. If we do need to redesign, fingers crossed it's for the first alternative, because the other two are HUGE!

More tonight ...

Robothon 2010 Report

by Toni 10/24/2010 23:45

So today's the big day! Our first competition in five and a half years. We have two 'bots with us, and we're about to find out exactly how much we've missed in that time off. When the 'bots were packed they were both in working order, so no "building in the hotel" this trip, which is a stark departure from how we used to do things! Click Back after viewing an image.

After a good night's sleep we stepped out onto the hotel room balcony to check the weather - cloudy with a hint of sun. Still, nice view! Lake Washington is pretty big ...

It didn't take too long to drive over the 520 bridge to the Seattle Center area. The competition is being held in Center House, which is in the shadow of the Space Needle - cool! Well ... it would be in the shadow of the Space Needle if there was any sun to cast a shadow ... not that it really matters, as we'll be indoors fighting! After a few false starts we finally found where the competition was being held (in the food court) and plunked down our stuff, to meet and greet competitors and staffers, familiar and not.

As folks began to arrive and unpack, we checked in and paid our entry fees, then hooked up some batteries to the chargers and hunted down a cup of coffee while we waited for safety inspections.

The arena had been set up yesterday, and so we were able to get right in to do checks and make sure everything ran properly. During a test-run for Nihilistic Naysayer 1.0, however, it suddenly stopped moving. There was no response at all, and we had no idea what happened! One second it was driving around just fine, the next it was dead in the water. We grabbed the 'bot and took it back to the pit to check it out. Hyperbolic Hoops 1.0 passed testing just fine, so we spent the time worrying about the drumbot.

The official competition start time drew close, and we had narrowed down the problem to either one of the drive ESCs or the PWM booster cable plugged into it - without that cable plugged in the rest of the 'bot ran fine. With it plugged in the 'bot went nuts! Unfortunately we hadn't packed a spare of either of those things, and no-one else in the pits had any spares - Victors aren't that common in 12lb'ers.

At this point we put the problem on the back-burner because it was time to fight! The competition had started, and we were up next with our beetle. We picked up the 'bot, radio, and power key, and headed over to the box for the first time in over half a decade!

Ah well, you can't win them all! :-) It was such fun to be back in the arena, and although it wasn't a win it was neat to see Hyperbolic Hoops 1.0 finally move, after all those years languishing as a Pile-o-Parts. You can see the damage Idiot Savant did - the right wheel pod has been tweaked, and we didn't notice until we put the friction wheel back on, but the gearbox in the Copal motor enbedded in the wheel pod has a very crunchy gearbox, so it's probably shot. This could be a bit of a downer - but we'll see if we can get it going after our first match with the drumbot - we're being called up to the arena. Unfortunately we weren't able to replace either the Victor or the cable, so we've unplugged it, and we're going to have to run with one side of the drive train out - hopefully we can fishtail about enough to put up a fight!

Yes ... Well ... Ah, what the heck: it was fun! :-) Deciding to go in with only half a drive-train probably wasn't the smartest move, and things are looking a bit like we may not be able to do a pit repair on this injury.

Under the lid, you can see the extent of the damage Nihilistic Naysayer 1.0 received from those hits: both motor mounts have cracked, both motors have been tweaked, and one of the gearboxes has pretty much exploded inside the 'bot, throwing gears and even the external gear ring all around the 'bot! At this point I'd reasonably expect the Victor that was working okay to be damaged, and of course we've lost one of the teeth from the drum. But still, it was a lot of fun!

As you can see, all the bolts were ripped out the back of the side rail when the rear plate was bent. The total amount of damager here means there's really no way we can repair this with the limited spare parts we brought with us, so we're going to have to forfeit the loser's bracket match - Nihilistic Naysayer 1.0 is out of the competition.

Looking on the positive side, though - the weapon motor and speed controller appear undamaged, so we just have to build a new 'bot around them for Motorama 2011 :-)

While the competition was on a break for a quick lunch, we chatted with Brett Dawson, builder of Daisy which was a stunning machine that didn't quite manage to show it's true abilities at this event. The 'bot was made in two parts, with the drive train having it's own receiver and batteries on the left, and the spinning shell being similarly equipped. The metal pieces around the drive train are magnets, and inside the shell on the top side you can see wire coils - the whole 'bot is essentially a big brushless motor!

Extremely impressive, and also got us thinking about a possible upgrade for Hyperbolic Hoops 1.0. Brett was happy to chat with us about designing and building brushless motors, and it was a real education to see some of this stuff - very clever, and leading us to all sorts of ideas!

While the competition was ramping back up we took the backplate off the drumbot and checked out the damage close-up. There were gears all over the place from that damaged gearbox! We ended up giving the mangled backplate to Dylan, the builder of Rockwelder's Revenge, as a trophy.

The competition is rolling again, so it's time to put the battery back into Hyperbolic Hoops 1.0 and button it up for the arena. Unfortunately we're putting it in with only one side of the drive train working, which didn't work out so well earlier today, but there's not a lot we can do. Hopefully we can get some hits in with the weapon before the other 'bot takes out the other side of the drive ...



Alas, the indominatable TeaBot had it's wicked way with Hyperbolic Hoops 1.0, and as that was our second loss with the beetle it was out of the competition. It was a fun match, despite only having half a drive train, and we were happy to have gotten back into the swing of things.

    What we accomplished:
  • Made it to a competition with two 'bots!
  • Managed at least one match with each 'bot.
  • Made Hyperbolic Hoops 1.0 move after seven years :-)
    What we learned:
  • Having only one side of the drive train working is not enough.
  • The wheel pods on the beetle needed rollers under the hoops to stop them popping out.
  • Flying with LiPo batteries in a carry-on bag is no big deal.
  • The people involved in this hobby are still great fun to hang out with.
  • Competing is still as much fun as we remember!
  • After being out for five years, we're now ten years behind the curve :-(
    Where we go from here:
  • Redesigning and rebuilding Hyperbolic Hoops 1.0
  • Redesigning and rebuilding Nihilistic Naysayer 1.0
  • Building up the fleet for Motorama 2011!

Ready for Robothon 2010!

by Toni 10/21/2010 12:00

We didn't quite have enough time to finish an antweight, but we've packed up the Pelican case, and we're ready to roll! We're taking Nihilistic Naysayer 1.0 and Hyperbolic Hoops 1.0, and after a couple of days of sight-seeing in we'll be putting them into the arena - our first competition in five and a half years! Looking forward to meeting the competitors and staff - see you all Sunday!

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Comps

Presenting Hyperbolic Hoops 1.0

by Toni 10/18/2010 22:00

We finished up yesterday with a handful of remaining items to complete for the build of this beetle. The level of anticipation was quite high, especially considering that we started this 'bot almost seven years ago! It's going to be great to see it running finally. Click Back after viewing an image.

First thing for this morning is to drill and install a 1/16" steel rollpin to connect the blade to the weapon shaft. Not only do we successfully complete this, but we don't break a drill bit in the process - an auspicious start! :-)

Installing the power light - a simple 12V lamp from Rat Shack. At least there's no soldering involved.

The innards are starting to be put into place. We added a couple of cable-tie anchors to keep wiring in place and away from the spinning can of the weapon motor.

We hit a small snag mounting the receiver using a cable-tie anchor - it took up too much room, meaning the receiver hit the battery. We had a bit of a rethink to see how we could mount the receiver ...

... And came up with this: Some double-sided sticky tape. Even if it comes loose, with the front wall on, there won't be too far for it to move, as the PWM cables to the drive speed controllers don't have much slack.

Things got a bit cramped around the power switch, but we were eventually able to tie everything down and keep it away from the weapon motor. Pretty fiddly, and we're glad it's done!

On the back side of the 'bot we're trying to keep the wiring neat here too. We've already realized we put the battery in the wrong way - it's leads won't meet the connector right in the middle of the 'bot.

Dealing with the battery is fiddly, because it's a tight fit, but at least that means it can't bounce around inside the 'bot! Here we've plugged in the battery, and there were no explosions or sparks, which - to us - means one thing: we're done!

The next big moment is powering the 'bot up for the first time - as you can see here we did that, again with no sparks or melting parts - cool! At this point we attempted a test drive, and it went absolutely no-where! Frustrated we looked the 'bot over to see what had gone horribly wrong. It turns out that the spacers under the hoops (to prevent them from falling too far down the pod) we causing too much friction for the hoops to turn. We removed them:

Cool! Now we know it can at least move, it's time to check the weight, and see what the bad news is. As you can see here the total weight is 3lb 1.2oz ... not good.

Out of curiosity we took the rear plate off - 2lb 15.7oz, so each plate weighs 1.5oz ... if we could use thinner polycarb we'd make weight. Luckily we had some available.

And here are the new panels. The drilling was a bit iffy, but we're okay with that. As you can see they're pretty thin - don't tell our opponents!

We never did get around to ordering any 2.25"-long #6-32 bolts, so we've decided to Dremel off the excess. That should save us a bit of weight.

Ta daa! Between shortening the bolts and replacing the panels we're now at 2lb 15.6 ounces, and we're very happy! Note the funky way the hoops are hanging in the pods - that's because of the removed spacers. Could make for some interesting driving in the arena :-)

Time for a beauty shot. All in all we're pretty happy with the 'bot, although there's still one more thing to test: the weapon!




Hmm ... not so good. Time to go do some research to try and find out why the weapon setup is being so temperamental. This sounds to us like "cogging", although we're certainly not experts, so we'll post a couple of questions on the Forum too. We're wondering if the motor is too wimpy, but when it finally does 'catch' and spin up, it spins very nicely. So perhaps it's the speed controller. We've done as much as we can for tonight, and - periodically - the weapon does spin up, so we're going to call this 'bot done!

Running Down the Beetle Build Checklist

by Toni 10/17/2010 23:30

Buoyed by yesterday's completion of Nihilistic Naysayer 1.0 we turned our attention today to the beetleweight Hyperbolic Hoops 0.9. Our checklist of things to do for this 'bot is smaller than the 12-pounder's was, but we still have plenty to be getting on with. We haven't done anything on this 'bot in over two weeks, so we'll have to pull our fingers out to wrap it up if we're taking it to Robothon. Click Back after viewing an image.

Here are our re-done parts sent to us by Team Whyachi, following a lick of paint. We're hoping the precision in the waterjetting means a simpler build for us as time is short.

At some point we're going to want to mount front and rear plates, so we edge-drill the top and bottom, and tap them for #4-40 bolts. At this point we're beginning reassembly, and wishing we had some #6-32x2.25" bolts to work with - these 3-inchers are huge!

We've pressed the weapon shaft bushings into the new pieces, and also figured out the Macro mode on this camera - bonus! :-) You can also see the spacers we've traded in, in place of our poorly-fabricated UHMW shaft sleeve.

Already we can see that things are lining up just fine - the weapon shaft slips right through to the blade beneath. Cool.

A bit more test-fitting: the weapon motor is bolted into place on the baseplate, and it's pulley is slipped on, along with the timing belt for transmission, and everything is looking great!

Checking our other components and finalizing a layout. At this point everything but the front and rear plates, and a few fasteners are to hand, and ready for assembly.

Here we've drilled the weapon shaft and it's pulley for a #4-40 bolt. Originally we were going to use a roll pin, but wanted and easy way to remove the pulley if we needed to take the top off for repairs in the pits. We're also going to cut off that excess shaft on the right side of the pulley to save some weight.

With all that done, we also enlarged the bore on the motor pulley by 1/64" and everything sits nicely aligned. We're happy with this setup, and we can move on to one of our least favourite parts of 'bot-building ...

Yay for Macro Mode! What you're seeing here are a pair of [antiquated] SozBots ESCs that were pulled from Gestalt Gastonade 0.9. They had leads already in them, but they weren't the right length, so we've de-soldered them clean, and started attaching new wires. We've doubled up the power leads on the one on the left, because we want to 'jumper' over to the second controller and save the weight of connectors.

Like so. Not the neatest, but hopefully serviceable. Next we need to move on to motor leads, and soldering up the weapon motor to it's controller.

Here we've just about finished soldering the Jeti 18A ESC to the Nippy brushless motor. Pretty straight-forward, and the motor actually had pads of solder already on the connectors - handy!

The first drive motor is soldered to a speed controller. This time we're already remembering to switch the polarity of one of the two motors so they both roll in the same direction when we say "forward" ...

The front and rear plates have been cut from 0.093" Lexan™ and given a quick coat of paint in the Paint Shack. We've already drilled and countersunk them for the #4-40 bolts we'll be using to attach them.

The red and black wire you can see taped up on the weapon ESC were leads going to a switch. We cut the switch off and soldered the leads together. Now we're working on mounting the internals.

Looking through the body of the 'bot you can see we've bolted down the weapon motor, and also bolted the drive ESCs to the roof. The weapon ESC will live under the power switch on the left side.

We've had to switch from our original battery (a 2.2Ah 3S LiPo pack) to a 1Ah 3S pack as we went way overweight with the larger battery. Hopefully 1Ah will be sufficient capacity for a match - it was the only other pack we had handy.

Drat. Even with switching to the smaller pack we're still slightly over-weight, and that's without a few bolts and things. We decide our best course of action is to just carry on and get the building done. If we need to shed weight at the end, we can deconstruct later.

While we mulled over how to lose weight, we wrapped up for the day and cleaned up for dinner. There aren't too many things left on the checklist for tomorrow night, so fingers crossed the rest of the assembly goes smoothly!

Shhh! Don't tell the Boss!

by Toni 10/6/2010 15:57

We're not usually ones for mixing business with pleasure, but we had to do a quick bit of "building" here at the office, as a small box of waterjetted parts just showed up from Team Whyachi. Click Back after viewing an image.

Here's a new top plate and bottom plate for Hyperbolic Hoops 0.9. We figured we'd have material left over from the other parts in this batch, and so we had Team Whyachi go ahead and cut us a more precise set.

Here are the frame parts for Poor Punctuation 0.9. There's a number of each type, as we wanted a few spares. At first we weren't sure why they looked so ragged, but eventually realized that the clingfilm that was coating the polycabonate was ragged - the bare parts look perfect!

Here's a fake 'build session': slotting four of the frame pieces together - they look exactly as we envisioned them from the CAD. This will be a fun, jigsaw-esque build.

Orange you glad I didn't say "Banana"?

by Toni 9/26/2010 22:55

I know, it seems like we're focusing all our time on one 'bot, but this is just until parts for the other 'bots show up - honestly! It's so convenient to be able to walk out to the garage and do some work that we can always find something to do. Here's a bit more progress on the beetleweight. Hit Back after viewing the images.

After realizing that McMaster wanted four bucks each for a 10mm bronze bushing, we decided to drill out a 3/8" one for the weapon motor. Turns out our drill press vice isn't as sharp as it used to be, and isn't that hot at holding round things, but we persevered.

To help in prepping the top plate and finish the bottom plate we printed some specs from Rhino3D. We found a while back that if you add a Diameter measurement to a drawing it gives you a handy cross-hair in the middle of your hole to drill.

So then we take the print-out and slap it on the part, and that makes punching the holes to be drilled a snap! Some of them were even close to center ...

Turns out we're a little rusty in our fabrication skills ... a couple of the drilled holes weren't exactly in place, but thankfully they were equally off on both top and bottom plate, as we'd drilled them both at the same time, so this means we'll switch the UHMW spacer for four threaded aluminium ones, and life will be just fine.

Not too bad ... with only one through-part things seem to line up okay :-)

A few more holes in the top plate and things are looking good. The more we drill, the more we remember about laying up a part, the foibles of our drill press, and so on. Perhaps we should make some swiss cheese, just to get our hand back in ...

Doesn't look like much, but this was a great moment - realizing that we'd actually been pretty darn accurate in drilling - SDP/SI's calculator said our center to center distance should be 2.4668" ... we measured 2.4670" using the calipers ... not too shabby!

The motor pretty much lines up with it's mounting holes on the baseplate too ... so with any luck it might even turn!

After checking the fit with the drive pods installed, the weapon axle doesn't turn quite as freely as it did when it was the only thing between the top and bottom plates - no big surprise - but it's still quite good, and we're thinking that with a little persuasion everything should come together just fine.

Weight is still good - 2lb 9.0oz so far ... with a battery being the only major missing component. We're planning on adding some 1/8" polycarbonate front and back plates once the rest of the build is complete.

Last piece for today before this sinus headache drives us inside - the weapon blade has a 3/8" hole drilled in it ... takes a while stepping up in 1/32" increments, but it seems to have ended up right where it should be! There'll be a 1/4" thick washer under there, with 4 #6-32 bolts connecting it to the blade, and a 1/8" hardened roll pin will secure it to the weapon axle.

Another Step Forward Beetle-wise

by Toni 9/25/2010 23:49

You know, the process of turning Hyperbolic Hoops 0.9 from idea to actual 'bot is ... interesting. We used to get an idea, go straight to CAD and design it, then send out for parts and begin a build, using the CAD as a reference. Aside from the five-year hiatus, the other interesting aspect to building this particular 'bot is that the process isn't going like that at all. We had an idea, sketched it on paper, CAD'ed a few aspects of it, then went to build, and pretty much have been winging it all the way. The upside is that we can find things to do to while away free time, but the downside is that we don't have a master-plan. Still, it seems to be coming along nicely!

Before we get too far, here a quick shot of the most recent bits of gear that we've acquired as we re-tool, re-arm, and re-hydrate! The Spektrum DX6i replaces our beloved 9CAP, stolen from California. It was a good deal, but came with a receiver that is illegal for 'bot competitons as not all channels failsafe properly, so we also ordered AR6110e micro receivers for the three 'bots we're taking to Robothon at the end of October. Also in shot are a multimeter (no idea what happened to our old one), a cheap caliper (again, the old one is MIA), and some spray paint in classic Team Radicus colours!

Oh, we also picked up a 9V battery for the small scale - the dead one had a best before date on it of 2004, so no wonder it didn't work ... As you can see we're up to 2lb 6.9 ounces for Hyperbolic Hoops 0.9 with a few pieces yet to make an appearance, such as a top-plate and battery pack, but between them they'll only weigh four ounces-ish, so we're still doing fine.

After breaking out the tablesaw and being careful to miss fingers, etc., we've cut a top-plate from 0.25" polycarbonate, and also trimmed down the center UHMW tube to 1.5" to match the motor mounts. As you can see we have 5.5 ounces left to work with ... the battery weighs a touch over an ounce, which is the only major component missing, so there's a good chance we'll be able to add front and rear panels, which would be handy!

More Beetle Work

by Toni 9/22/2010 22:45

It's really nice to be able to step out a door and be at the Build Space - no need to go driving across town to tinker on a 'bot when the mood strikes!

A few parts had shown up, so we decided to cut axles and try to prep as much as possible for a big push this weekend to get as much of the Beetle constructed as possible before the batteries arrived.

Here we're pressing a 1/4" aluminium spacer onto a Nippy 18/12 brushless motor. The inner diameter of the spacer was a touch too narrow, and the spacer 'flared' out, so we'll have to run a file over it.



We have no idea why we thought it would be a good idea to use a hacksaw to cut the sleeve for the main weapon shaft - probably because we were too lazy to pull the tablesaw out from behind the bike. Not a smart move - but oh well.


Boring out the main weapon pulley to 3/8" from 0.3125", in 1/64" increments. We really wish we had a lathe ...




... But hey! It worked just fine. We'll eventually pin the pulley to the shaft with a 1/8" rollpin.



This is right around the time when we realized we'd made a bit of a mistake in determining where the weapon motor is supposed to go for the length of timing belt we're using, so we had to think again about the layout of the internal components ... a 112MXL belt has a length of 11.2", not 112 teeth! Doh!


But no matter ... we're ready for our SDP-SI and HobbyKing orders to show up!

Working on the Beetle

by Toni 9/19/2010 16:42

Despite the fact that none of our recent "Gearing Up" orders have shown up yet, we started digging to see what we could work on in the meanwhile. Our original work on our beetleweight was sitting in a box, so we decided to see if there was anything we could do to get it closer to completion. Hit Back after viewing an image.

Well now ... this all looks rather familiar. The 1/4" polycarb baseplate, angled motor mounts, 6061 wheel plates and of course the hoops. And there's even a brushless motor sitting around ...

We pulled the wheels off Wobbly Wedge 1.0 and mounted them in the "poor man's lathe" to turn them down from 1.25" to closer to 1", as the design originally called for. We eventually stopped at roughly 1.125", feeling that would allow the wheel to make better contact with the inside of the hoops.

The wheels were mounted back on the Copals, and the wheel pods were reassembled. There is 5/8" of clearance under the baseplate, and the 'bot is wide enough for a 12" swinging weapon under there. We also pulled the SozBots speed controllers from the old fairyweight for use with the Copals.

Here's an initial layout, with the weapon motor and ESC on the right, and the drive ESCs on the left. At this point we don't have a battery or receiver for the 'bot, but both of those should be on the left side.

Checking weight - the small scale we have is dead, so we threw all the parts on the big Pelouze ... it says 2.2lb, which seems about right. We have a couple of ounces of battery and power switch to factor in, which should take us to about 2.5lb, then a top plate and hopefully side panels too.