Norwalk Havoc May 2021: Scale Model Testing Your BattleBots in Nightmare Mode

It’s time for robots once again! I think what I’m planning on doing from here is, barring one or two more Summer of Ven posts (which is now well into the Fall and Winter of Ven anyhow) I’m going to begin transitioning towards Overhaul, finally.

You see, a major over-winter project of mine was trying to get Overhaul 1 up and running again, at least walking. There was a good bit of fabrication and “What in the everloving fuck did we do here…” reverse engineering your own work from 6-odd years ago. While it’s cool enough in its own right, I’m planning on using that to move towards the long-overdue Overhaul 3 design and build series. I mean, y’all already know what the bot looks like since it’s appeared on here by now, but there was a lot of translation from 30haul’s geometry to the full size bot.

But in the mean time, let’s talk 30haul. Recall the “lessons learned” of the previous March Norwalk post

I’m revising the Snout design to be stiffer on the corners, trading the internal webs for a U-shaped bottom truss shape. The metal is rigid enough on this scale that I don’t think the center webs contributed much.

Next up, after watching enough Battlebots and seeing enough matches at this point, I’m going to make 30Haul an entry in the “fork wars” currently ravaging the combat robot landscape. The joke is that ground-scraping forks grew a foot over the course of the 2020 season, as one of the only ways to ensure a vertical spinner doesn’t get under you, is to get under it first. Keeping the opponent away and under control is just as essential as being able to take (or deliver) the hit…

I’m also beginning to like the Vex wheels less and less, because while they initially offered the bouncy compliance I was looking for, once they start disintegrating, they become more liabilities. The spokes will tear through, leaving the big gaps in the perimeter that then flap in the wind. I decided to try and find some thick foam rubber I can use to make at-scale foamy wheels, not dissimilar to Overhaul’s.

Before any of that can happen, though, I had to have a 30haul that was functional. The damage from March wasn’t that bad in the grand scheme of things, but in the name of thoroughness I decided to completely take the bot apart and remanufacture it to address some of the frame damage and retighten the motor screws, among other tasks.

So here’s 30haul in a pile of itself! I planned to repair the frame as much as I could and keep it around as a backup, because…

Prior to March, I commissioned an entire new chassis to be machined by Wedge Industries. I figured as long as I actually had new 30haul parts, why not just move the bot to the new chassis and keep the old one as the “Just in case…”

To save some expense, I had Alex pound out only the net shape geometry. Since I have my own capabilities, I save some on the machine time and setup when it comes to tapping and countersinking, among other operations. So the first order of business with this new chassis was just chucking the ol’ spiral-flute 1/4-20 into my drill and having a pleasant time.

To the old frame, I repaired the damaged threads in multiple frame rails with threadlocked Helicoil inserts. The rear bulkhead shown here was actually quite bent up from the Ripto match. I used my arbor press to straighten it using some cleverly placed spacers.

Original chassis coming back together with an added weight-shaving pocket that I designed into the one that was sent out for manufacturing. There’s nothing over this area worth hitting really, so no reason to have the weight.

And the original chassis fully repaired and assembled!

The new chassis needed the end-tap holes put in. The way to do this would be to set them up at an angle on the drill press, but I was confident enough in my drill bit rodeo skills such that I just clamped everything together on the bench and hit the front (angled irritatingly – that got designed out of Overhaul 3) bulkhead holes. The rear set I piloted and threaded in one screw before finishing the rest on the drill press.

New chassis fully assembled and ready for population.

Next item on the agenda was to make some wheels. I said earlier that I wanted actual foam rubber wheels for 30haul now to get away from the Vex wheels, as while they did offer the compliance I was looking for, their failure mode was becoming big rubber flaps.

I looked into a few difference sources of “rigid” foam rubber, such as anti-fatigue floor mats and similar. Ultimately McMaster-Carr came to the rescue with a sheet of natural rubber foam – the nice thing was, in the time I had, it just offered a compression/deflection rating in PSI so it was easier to visualize how much give it would have.

To manufacture the wheels, I initially tried to find a hole saw set where I could get a 4 inch and a 1 inch saw on the same arbor. Maybe this was possible in the ol’ glory days of Comedy Central Sports Presents BattleBots™ as I recall a few builders’ reports saying they mounted two hole saws on one arbor to cut washers (e.g. for clutches, spacers, and wheels as well). But these days the consumer systems seem to have evolved and specialized, so the smaller sizes of hole saw usually have direct screw-on mandrels and larger ones have the pin locking ones.

I ended up picking up probably the most horrible Chinesium hole saw set Amazon had to offer in the hopes that it had generic mandrels, but alas, I found that the D-bore of the saws were different sizes as well. Either way, I found out that just hole sawing into the rubber wasn’t bad for alignment anyway. It’ll become round once I do enough burnouts!

I drilled these wheels using the Vex hubs as a template and put the same hole pattern into them.

For now, I made only the two (well, four…) front wheel assemblies to alleviate the worst of the wheel compression issues. What would happen is the Vex wheels would flatten between spokes and then bounce up once it reaches a spoke, and it actually made the bot drive a little bouncy as a result. These are a good deal lighter than the Vex wheels as well.

Hey, no use in spending too much time making wheels if I don’t have the rest of the bot yet. So off we go with populating the new chassis!

While doing so, I re-discovered a problem that might have prevented 30haul from being able to lift much. Recall that I had to step down from a 3-stage P60 gearbox to a 2-stage because the torque of the 3-stage type was rounding off its own output spline. This design stands in contrast with Overhaul 2 (and 3) because 30haul doesn’t have an intermediate gear stage, the lift motor directly fiddles the Big Gear.

I noticed the motor would bind up whenever I spun the gearbox one way. It turns out the output spline on this gearbox was deformed helically in a fashion that positive torque (lift) tended to shove the carrier off the spline, causing it to bind up like a clutch plate against the first stage.

Well, to repair this, I’d just have to replace the output shaft. Trouble with that? To clear the Big Gear and lifter forks, I had to position the motor farther away from the sidewall with the support bearing. Namely, about 2 inches. The stock Banebots P61 gearbox has a 1.5″ shaft.

I was at a juncture where waiting for Banebots shafts to be ordered would mean delaying the bot’s assembly into the week of the event, which I really didn’t feel like doing. So I decided to make a shaft extender, just a turned piece of 7075 rod with a 1/2″ socket on one side and 1/2″ stub on the other, long enough to bridge the gap. A 10-32 screw goes through the middle into the end-tapped P61 shaft.

Here’s what it looks like installed, along with the rest of the motors. Again, the motivating factor here was just to be able to reach that outer support bearing with a stock-length P61 shaft, of which I have plenty of spares.

Wheels loaded on and chassis off the ground now. I like these front wheels already – they don’t cause the front of the bot to sag at all, but are still very bouncy. Boy I wish someone made 3-4″ thick chunks of this stuff!

I finished assembling the bot and put it in “Sportsman Mode” since I didn’t yet know who I was fighting at the time – I’ll change things once I get there. In the time between this and leaving for the event, I put together what I think are the last two 6-fet Brushless Rages left and readied some other spare parts.

You see, by checking out the registration roster, I found out that every other 30lber was a vertical spinner of some sort. Whether disc or drum, this tournament was going to be absolutely fucking brutal. Hence why the title is….

Scale Model Testing Your BattleBots in NIGHTMARE MODE

I teleported up to Norwalk over the course of the day on Friday, May 14th, and got to my (now usual…) Norwalk generic business hotel around 10pm. The event started at 9 the next morning, and it was a full house.

I started 30Haul out in the “sportsman mode” configuration anticipating needing to change out to anti-vert forks. I got “Hyperbite XL” as a first draw. It’s an homage to Deathroll from BattleBots, and luckily was very high off the ground, so I actually decided to roll with these. I was out to test a “Just reach out and grab it” strategy.

Hear me out here – pretty much every vertical weapon worth its mettle takes a few seconds to get up to dangerous speed. I’m content with declaring the clamp disposable and just going up to it and grabbing it. If they try to turn away to prevent this, so much the better.

Well I mean it kinda worked. The only downside of declaring the clamp arm disposable, is you better have a whole lot of them, which I… didn’t. So this was the outcome of “Just grab Hyperbite XL as it’s trying to spin up” – while I was able to keep it at bay, the buckling actually jammed the clamp motor so I couldn’t grab and lift so much as just toss around.

There’s no “stream clip” like some of the other matches, but the match is at 3:12:36 in the main stream recording.

Hyperbite XL managed to machine some of the tips off the forks and snap some of the threaded rods, all from the small amount of contact we made in the match. That’s the downside of fighting a modern vertical spinner – there’s so much power density that the damage slope is very steep. You can really just mess up once.

Nonetheless we were both thrilled enough with the outcome that we decided to call it “Overhaul vs. Death Roll”. See? Battlebots should just be 30lbers.

Great, one match in and I’m already on my spare clamp. I managed to hammer the other side of the first clamp (the half that didn’t become wall art) straight, just in case I had to use it again.

Of course, the next match was against Other Disko, which is a more traditional 4WD vert architecture and multiple-time champion of northeastern events. Great. Luckily, this meant i got to bust out some experimental “Vert Blockers”, extended forks that act as a ground-level push-me stick. There was a lot of fork and counter-fork action at BattleBots this past year, so I decided why not give it a try as well.

This one was fairly brutal and took a long time to recover from. The key takeaway is that Vert-away forks work until they don’t. I mean, the opening gambit was about the best I could hope for, and then it just became pear-shaped.

I think that’s my main beef against the KE meta, really. That because of brushless and lithium batteries, there’s no more compromises that need to be really made on that front. You can have a fast and maneuverable drive, a solid chassis, and an extremely effective weapon, so there’s little point in having anything else.

At one point 30haul must have gotten booped hard enough on the snoot to buckle the leadscrew that drives the clamp. Luckily I decided to actually cut one of these as a spare, or else I might have had to resort to being a lifter only!

(Maybe that would have been better….)

I next faced Marathon, which was an “Overhaul vs. Minotaur” moment, and I was rather pleased by the outcome except that Marathon was counted out under what we think were incorrect conditions. I was still manipulating it when they pulled up the countdown. I was extremely peeved to find that for some reason, perhaps due to accumulated damage and misalignment, that I couldn’t manage a lift after the grab – something was stalling out the lift motor.

(I would find out after the event when I tore the bot down that one of the matches before, likely Other Disko, had bent the lift shaft into a shallow U shape that was binding up if it had much load on it)

By this point, I’d basically run out of fork parts and standoffs, so I was just going into the last match against Stop Hitting Yourself in “With your shield, or upon it” mode. I think it was a little more “upon it” as the dual vertical disks slowly plucked the remaining wheels I had cobbled and assembled out of whatever still was kind of whole.

I mean, in the grand scheme of things, the extremely prototype-y nature of 30haul has been its downfall all along. I was more out to get the shape correct and get a feel for how it’ll drive instead of focusing on functionality, and it still ended up using a few legacy parts from 30hauls and Uberclockers past.

The most important thing was I got a lot (a whole lot, let me emphasize) of recon on how to handle the vertical spinner EDM party that is BattleBots. A lot of the design issues I didn’t like about this 30haul had already been changed on Overhaul well before now, so I got to leave Norwalk this time with some “hmm” lessons for Overhaul, such as….

  • Just grabbing the vert is a valid approach, as long as I can line it up or force them to turn away.
  • The clamp head and forks are considered disposable and will be both treated and duplicated as such.
  • Vert-away sticks work until they don’t, and I’m not sure I’m a judicious enough driver to use them effectively.

I never actually got to test the new “snout” spinner wedge, first because there weren’t any horiontal bar or shell weapons, and second because I just never finished welding it after seeing there weren’t any! To be fair, Stop Hitting Yourself had a horizontal component, which would have been trouble if they decided to use it against me.

Hey, at least a clean picture of 30Haul is on the NHRL hall of fame wall! I think this photo was actually taken during the February one I went to.

With this NHRL, this 30haul’s story comes to a close. Like I said, it well outlived its original purpose and I was just running against opponents with a whole slew of design handicaps. There will be another one in the future, probably not this year, as Overhaul itself is now my focus of attention. And of course the new one will have conversely back-propagated design elements from Overhaul 3!

Norwalk Havoc Robot League, February 2021: The Culmination of All of My Worst Nightmares

When we left off the previous episode, I’d just gotten the new attachments cut by Big Blue Saw and gotten them back. So with but a week to go until the competition, it was time to put all these pieces together and prepare the bot!

These pieces were cut from the same Hardox 450 (HX450) stock that I’ve had Overhaul bits made from since 2018. Basically, it turns out Kloeckner Metals, through whom I had Overhaul weldments-to-be cut out, does NOT reuse partially cut material.

If you buy one custom-cut part, you basically bought the whole plate. As a result, I asked them to slice everything else up into 12×24 rectangles so I can chew on them for years to come. The 4mm thickness in particular has seen application across a few 30Haul changes and even Roll Cake.

The nice thing about genuine grass-fed, wild-caught SSAB Hardox steel is that it’s very uniform in thickness and has a coating applied to it that grinds and sands off very easily to reveal clean metal. So much AR-grade steel is naturally bowed and comes covered in tough (abrasion-resistant, almost…) mill scale.

Above, I’ve already cleaned the pieces with a flappy wheel and have made initial tack welds to hold the shape together.

I did all of this with good ol’ Limewelder, which I discovered recently actually kicks some ass on 240 volts, so much that I’m going to get 0.035 wire accessories for it. I started off with 0.030 because of the need to do light sheet metal work on Vantruck, but on 240 volts it becomes the bottleneck for how much steel I can lay down. There’s some exciting Limewelder work to come yet.

More metal being smeared upon itself here. I generally decline to call myself a welder, as being a welder implies you’re well trained and practiced in the art and science. I prefer to say I host exciting meet and greets for metals.

The parts were joined at the tab-slot interfaces first to lock them in place, I suppose being a pseudo plug weld. Large fillet edges were done last and in a few stages to discourage warping. In this 4mm material, I can pretty much just turn Limewelder up all the way and draw lines – it barely has enough power to just make large stringer beads in this thickness, fillet welding in one pass. Any thicker and I’ve had to bust out my unsteady random-walk weaving, making everything worse.

You know what they say, a painter’s welding is a grinder I ate…. …..or something like that. The completed assemblies were primed and then painted in my favorite generic black robot spraypaint, Harbor Freight Spray-On Bedliner. I can’t imagine anyone actually using that stuff for a truck bed, but it does make a nice matte and lightly textured surface on robot parts that seems a bit more durable than the usual Rust-a-Color.

Hey, remember the “Open Loop Aluminum Donut”? Well, to my utter amazement, all seven holes of the bolt pattern went in without any encouragement. While I’m disappointed at not fitting digital scales to the Benchmaster, Master of Benches yet, I’m also happy to know I can always fall back on “well fuck that” machining techniques.

When all is said and done, here’s 30Haul set up in “generic” mode for Norwalk Havoc. I figure I’d change modules depending on who I was fighting first. The crash kit comprises a labeled spare hardware sorty-bin and a tote full of “Probably Most of Another 30Haul”.

This might be the first appearance of Overhaul 3 on this website, in real life. Because I basically stopped updating as WordPress died more and more, then picked up afterwards with moving and vans as I skipped BattleBots 2020, the entire design and build sequence of Overhaul 3 has been skipped. This is probably my biggest and most menacingly lurking back-blog that I have to do, and I already have the framework for it set up, but just have not mustered the willpower to begin writing yet.

The almost 1 to 1 relation between this 30haul’s geometry and that of Overhaul 3 can be pretty well seen here. No wonder I’m trying so hard to robot again, eh?

While I take forever to get to the write-up, you can see Overhaul get beaten by Sadbot over and over.

We now teleport a day ahead to somewhere in the dank industrial crotch of Norwalk, Connecticut. 30Haul’s been checked in and through the inspection and functional test now, so I get to walk around and check out the BRAND! NEW! NHRL building.

It basically expanded across the street from 50 Day which has hosted the insect-weight events. This is a brand new 30lber-rated cage, of a rather hybrid construction. It’s significantly sturdier than the NERC Motorama box, but is still made of wood for most of the floor sections.

NHRL’s thing is having a giant, slow house bot in the arena (which I support the concept thereof very fiercely), and I also identify with the general “there are no rules” interpretation of rules, especially as it pertains to multibots. In other words, this is not a place for the overly competitive to get uppity about following proper tournament procedures and fair judging. This is a quintessential #PostmodernRobotics experience.

A whole lot of gear and prep has gone into this facility – here’s a photo of the streaming battlestation.

So how did the robot do?

Horrible. Absolutely terrible by record, but I learned everything I set out to learn which, as I looked forward to this event as a shameless buffet bar sample for Overhaul, means I won without winning anything.

There’s not a split-up-by-match video available of the February NHRL, but there is a single stream capture that’s TWELVE HOURS LONG. I can’t actually be bothered to go through it to find the segments of video featuring 30Haul (entered as “This robot is not Overhaul”), so let’s get down to the details.

My first match was against Big Ripto of Motorama fame. Because _of course_ it was. I had no particular strategy going into this one, as it was more to figure one out. I’ve seen enough people do the keep-away dance with vertical spinners, and Overhaul 2’s “Wedges of Limited Liability” were made in 2018 as a way to decrease the attack surface against the likes of Witch Doctor and Warhawk (to varying degrees of success). But the 4 wheel drive vertical disc approach really came into vogue in the 2019 and 2020 seasons, which Overhaul had to sit out. Everything’s gotta be a Bite Force now, huh. In general, that time period was also when I was the most out of the sport as well, so I haven’t really had any actual match driving in over a year.

In all regards, this match went “fairly well” solely because Big Ripto suffered some mechanical and electrical problems. Kyle had issues with the belt drive on the disc becoming entangled, and it also melted a few wires. After the first few collisions, 30Haul had trouble driving much – because the Vex wheels had basically come apart and become little paddles.

On top of that, one of the good hits Ripto got on me actually managed to blow off the entire header on the 6-FET Brushless Rage. Why? It was the only one I somehow forgot to put the double sided mounting tape between the signal and power boards. The others were fine. This was, of course, on one of the drive sides, so between “flappy paddles” and dragging the left side, the rest of the match was a lot of Powerful Hugging.

The “Big Hit” pushed in the rear frame rail quite substantially, and this force transferred through the battery mounting bracket into the motor controller enclosures.

I was able to replace the closely-shaved Brushless Rage and flatten the frame rail enough for the top and bottom plates to fit back on. I learned next that 30Haul’s Losers Bracket match was going to be against Rum Ham, an undercutter kind of design. It’s a heavy hitter, but has historically been a little unreliable on the weapon. Nevertheless, it was a good chance to really test my assumptions when it comes to “T-rex Mode”.

So I began converting 30Haul over to T-Rex Mode. In real life (and for Overhaul) I would have this assembly pre-built and ready to be swapped in, or Bot 2 configured for it as soon as we know the first rounds of matchups. Just like Overhaul 3, the top half of the bot pulls off for independent service.

For the bottom half, I added the Snout using all of the available rubber bumper holes.

And the two halves go back together.

Well, it turns out 30Haul was about 11 ounces overweight in this configuration. I had to remove the (heavier than expected) Vex wheels on the outside, leaving just the chariot spokes. While we’d generally let even 3 or 4 ounces slide at most events, I personally felt almost a full pound over was just too egregious.

I was pretty happy with 30Haul’s durability this match, as I was able to keep the snout pointed at Rum Ham and cause it to destabilize a few times. I went for full speed connections as well – in a match with higher stakes, I’d be more likely to keep on the opponent, whereas I waited several times for Rum Ham to spin back up. Again, just seeing what goes wrong where so I can more effectively address it for Overhaul

I wasn’t able to leverage the situation, however, because one of the hits caught the very tip of the wedge and bent it forwards, which hampered 30Haul’s mobility a whole lot. It wasn’t _not_ driving, but was certainly not able to effectively maneuver.

In retrospect, a bottom brace/truss plate would have been more helpful than internal webs, and that’s one of the mods I intend to make right away to this design. I was otherwise very happy with the physics and the “rise through” functionality of the bottom forks. You can see that one of my “worst case mistakes” did occur, where Rum Ham caught the very side of the wedge and popped off a few of the rubber mounts on the corner.

Alas, due to my inability to follow through with the face-bouncing I did with Rum Ham, 30Haul was declared the loser of that round. I put it back together in “Sportsman Mode” for the 30lber rumble that never happened because the event had been running almost 14 hours at that point.

The next Norwalk Havoc with 30lbers is in May. So what’s the big plan?

I’m revising the Snout design to be stiffer on the corners, trading the internal webs for a U-shaped bottom truss shape. The metal is rigid enough on this scale that I don’t think the center webs contributed much.

Next up, after watching enough Battlebots and seeing enough matches at this point, I’m going to make 30Haul an entry in the “fork wars” currently ravaging the combat robot landscape. The joke is that ground-scraping forks grew a foot over the course of the 2020 season, as one of the only ways to ensure a vertical spinner doesn’t get under you, is to get under it first. Keeping the opponent away and under control is just as essential as being able to take (or deliver) the hit. There’s some amount of rumbling that BattleBots might restrict the “ground game” as it’s called, but we’ll see how that shakes out.

I’m also beginning to like the Vex wheels less and less, because while they initially offered the bouncy compliance I was looking for, once they start disintegrating, they become more liabilities. The spokes will tear through, leaving the big gaps in the perimeter that then flap in the wind. I decided to try and find some thick foam rubber I can use to make at-scale foamy wheels, not dissimilar to Overhaul’s.

All this and more in the next robot updates! Maybe when someone splits up the February stream capture I’ll link to individual videos.