The Restoration of Overhaul 1: Wait, Why Did We Do It That Way Again?

Last November, I made a trip back up to Boston in order to retrieve some of the heavy things I didn’t bring down when I moved. One of these heavy things I explicitly wanted to get was the hulk of Overhaul 1, which had traveled with me out of MIT, through the Artisan’s Asylum, into the Old New Shop, finally to the New New Shop.

There it is, in the cruft corner of the New New Shop. When the wheel modules went into sadbot back in 2015, the shuffle drive pods were put back in as a visual completion piece. The motors were removed for future other bots – I believe those drive motors might have made it into the Season 2 Road Rash. While they were never used in the Season 1 competition, they were the last piece of the purposeful “Glue 3 designs together” approach we used for Overhaul 1, and the focus of a lot of effort during the build.

Beyond missing a few motors, the bot was exactly in the state it left the Nightmare and Witch Doctor rumble of Season 1.

This was the same trip that I acquired the Benchmaster, Master of Benches on the way up. I somehow managed to fill the back of Coronavan up without even trying. Thus is my life, apparently.

And thus, the conference of heavyweight robots is convened! The still unpainted Overhaul 3 is in the background. As I’ll expound on in its build reports coming some day soon, part of the design mantra was getting back to the roots of what I liked about Overhaul 1. I wanted Overhaul 3 to drive like Sadbot – as a result, I wanted it to drive like OH1. That meant going back to large, bouncy wheels over the old Biohazard inspired 6WD setup of Overhaul 2, and if you recall, 30Haul was made two years ago to explore the same.

My plan for Overhaul 1’s resto was to straighten the frame out so I can easily mount stuff to it again (but not repairing the battle damage!), and then putting some motors back in it. The old battery bay was to become an electronics-and-battery bay since it wouldn’t need enough energy to last a 3 minute match, just to drive around. The actuators for the lift and clamp were in fine enough shape and would just be taken apart for a quick inspection and rebuild if needed.

I began taking the thing apart and assessing what needed to be done. The right side of the frame was caved inwards from Nightmare brushing against it, for instance. This really prevented the shuffle pod on that side from being fully mounted (Its sidewall was also a little caved in, but not enough to matter apparently). Dings, dents, and nibble marks abounded on the rest of the bot.

The “pontoons” in the front warped when welding, so it was already bent anyway, but during the tournament it just ended up bending more. So I also had to figure out how to pull that straight.

I decided to force the frame apart hydraulically from the inside. Doing just enough Big Chuck’s Auto Body to have watched enough repair videos of car and truck body and frame pulls, I was out to try my sense of “understanding how the metal flows” when taking damage. Nightmare pushed the steel inwards, so pull it outwards again to compensate.

Initially, I tried with Mikuvan’s OEM tire jack. While it’s fine and enough for lifting one cheek to change a tire, against the AR400 steel plate and tube weldment, it was just… no.

And so I found myself running to Harbor Freight before closing time to get one of their big 20-ton bottle jacks. With this thing and a cleverly positioned Spool Bus Lifting Tool, I was easily able to force the frame rail back straight again by targeting the upper edge (where it got chewed first). The rest followed without much fuss.

While the tubing is crimped a little on that side now, it doesn’t matter, since all I need is the clearance. The damage is character.

I flipped the frame around to also push out the other side a little. An AR500 plate sits against the bottom of the jack and the recently corrected frame rail in order to boost its rigidity, such that I didn’t just balloon both sides of the frame outwards. I was plenty satisfied with how straightened the whole thing became, really. I didn’t expect it to work out this well!

For pulling the pontoons apart again, I had a creative method in mind. To execute this, I’d first need to weld a pull tab to the end of one of the pontoons. The idea being I’d fixture the pontoon center beam element to something relatively sturdy, and use a come-along or chain binder on…

…Yeah, what was anyone expecting? Dual vantruck metal forming.

I bolted the pontoon center member through one of the former 5th-wheel hitch mounting holes on Spool Bus, suspending it slightly off the bed by using spare Overhaul wedgelets as a spacer. This would allow the beam to deflect the other way as it was pulled. I wrapped the tow chain I keep in Vantruck around the pull tab and joined it up with itself, then attached the other end around the trailer hitch.

I then used a come-along to slowly pull on the length of chain. It looks and sounds far sketchier than it was in real life, but I made sure to use double layered eye/face protection and an few “Anti-kill-yourself” blankets over the chain and cables.

I mean, not that any of that stuff would do much against a potential flying 37 pound pointy steel thing, but it made me feel better about it!

It’s not totally straight (not that it ever was), but it’s better than before for sure. At least it’ll be straight enough to get the bolts started.

With all the frame bashing work I wanted to get done completed, I next moved on to the question of how to put motors back in it. Originally, we had just hung F30-400 Ampflow motors off the sides of the shuffle pods/wheel modules and used some tie rods to secure their back sides. This worked well enough for the time we had. I wanted to execute on an idea we bounced around but did not move on because of the extra complexity.

See, the motors I wanted to use were some XYD-13 24 volt scooter motors that I originally got as a what-if for Overhaul 3. I’m perennially of the opinion that these big ol’ scooter motors are underloved in the U.S. robot fighting scene (but rather popular overseas in the U.K. and Australia, as well as mainland Europe). Uppercut, the team of MIT ducklings from yester-season, also did very well using them for drive.

The plan was to center-mount them in the bot and use flexible couplings to connect them to the shuffle pods. Those seemingly random frame holes near the center of the bot’s wheelbase that were never populated? Well, that’s what they were originally for: Motor mounting.

This is what the arrangement will look like. The motor will drive a very short floating intermediate shaft made of spider couplings, in theory giving them a lot more isolation from the high vibration of the shuffle pods. Now I just needed a way to connect the motors together with themselves.

I decided on the fast, easy, yet effective way – use a Markforged print designed to give a little bit of rotational flex to hang the motors off the two long rails. The motors will be held together with 2 of these and standoffs as a central unit.

Here’s what the design looks like. The three holes are for the motors’s mounting flange, which will bolt through to standoffs.

And this is what it will look like in the design. The former Ampflow bolt pattern will have a small (also 3D printed Onyx) bearing block embedded in it with two flanged 1/2″ bearings to support the drive sprocket.

The design now finalized, after some adjustment of spacings here and there. The motor “pod” itself will be held in place by shaft collars, so I can make everything jiggly at first to do the side-to-side alignment before locking it in.

Fabrication of all this didn’t take too much time. So the next post installment in this “Charles really doesn’t want to start down the rabbit hole of recapping all of the Overhaul 3 content thus far” will be about getting the bot driving again!

The Summer of Ven: The Electrical Phantasmagoria of Murdervan

Here’s a surprise retropost for you! I actually blocked out this post about Murdervan from a template some time last August, before I sold the sitevan and bought a new one. I ended up never finishing it in lieu of updates about Spool Bus and quite a few robot events, because after all was said and done, Murdervan didn’t have much wrong with it. I put a few hundred miles on it just around town as a daily errand runner but with more curb jumping and casual non-roading – note I didn’t say “off-roading” for a reason, just going places that isn’t…. public paved roads. What, who’s gonna stop me?

By July, though, I noticed it had developed a habit of popping the fuse for auxiliary lighting. This meant no running lights, no dashboard lights, and so on. The horn was also involved, straightly enough. If I put new fuses in for either circuit, they’d go if I tried to turn on interior lights or …. use the horn.

What it told me was some ghostly electrical problem residing in the dashboard area, the kind of electrical problem that gets a lot of things junked, probably even more so today as cars depend highly on all sorts of electronics and software. Luckily, this thing is so paleo that it was probably shorted wires to ground somewhere, like from chafing or a previous overheating adventure that is only now manifesting. The only trouble is now finding where.

I’ve said frequently now that part of the upside of having a flock of misfit ven, especially a new cast member you dug out of someone’s yard, is that it helps alleviate the fear of “Well what if I can’t put it back together again?”. So what if I can’t? Murdervan was going to be a helpful lesson for any issues Vantruck might have in the future. So I just dug in and started removing all the dashboard panels and bezels to expose as much wiring as I could.

The usual aftermarket service manuals are pretty worthless for electrical systems, but at least they contain (usually several versions of) system diagrams with wire colors and general locations I could follow around. I started with the horn circuit, for example, which is a greenish-yellow wire. I found it in the steering column bundle and followed it outside the van through this bulkhead connector in front of the driver’s floor:

So by 1991, they turned what was just a big bundle through a body grommet (in Vantruck and Spool Bus) into an actual bulkhead connector. This is certainly an improvement!

I continued to follow the yellow-green wire around through the various harnesses until I confirmed that yeah, it just ended at the horns.

So…. What’s the deal? When the horns are used, presumably this wire is energized, and in doing so, bad happens. Very strange.

This is a view of the bundle that goes up to the steering column. The auxiliary lighting circuit, a blue-red wire, has a branch that goes up here too for dashboard lighting and the like.

Like any good and competent engineer, I started jumping fuses and put the whole van on one of my lab power supplies to give it a maximum of 15 amps into the various circuits. My goal was to feel around (absent having a FLIR camera on me) for what wires got hot as I held various switches and buttons down to energize the circuits.

This is a more legitimate method of finding shorts and high-resistance areas than you might think….provided you’re sane about it. I wasn’t, and with that 15 amps and non-judicious use of the horn switch, I started smelling terrible things.

Turns out I roasted the horn switch. Oops. The mystery still isn’t solved, but at least I’ve knocked one branch of it completely out of the picture.

As I continued to pump 15 amps now into the auxiliary lighting circuit, I felt the red-blue wire inside the bundle that went into the steering column get warmer. So the power supply feed to the steering column was acting up, and either it or the horn switch (in the process of giving the power to the horn circuit) was causing a short.

That means the steering wheel had to now come off. I actually bought a steering wheel puller a long time ago for Vantruck to correct it’s 15 degree “Left is Straight” error, but never used it because, again, I wasn’t in a good position to not be able to put it back together quickly.

Well now I don’t give a shit, so off the steering wheel comes! Under the steering wheel lies some slip rings and switches like the turn signal switch. Any one of those could be the source of the shorting problem.

I continued to dismantle the steering column as well, following the red-blue wire upwards. I noticed that it was grounded to the steering column at one end (that screw terminal in the middle) yet somehow also carried power. What?

More digging revealed that it wasn’t some kind of Ford Family of Fine Fuckups engineering choice to float the entire steering column at 12 volts, but that they just got lazy and used the same wiring color to go into this weird connector here that…. Hey, wait a minute.

I found out what this was: It’s the light bulb socket to light up the PRND69L transmission indicator. There is no light bulb in it. The contacts had for some reason melted together, and was Shorting the 12v auxiliary lighting feeder wire straight to ground through the steering column!

Well I found my villain there. Check out that burn mark where the whole thing heated up! Oddly enough, the contacts themselves were not damaged, just touching. I just pried apart the housing a little, back to its un-deformed shape, then stuffed in an obnoxiously bright T5-sized white LED bulb, and suddenly, all was fine.

I’m not going to ask questions about how this interacted with the horn circuit. The only possibility I can think of is, this auxiliary circuit also supplies power to the horn, and when I close the switch, it just finds a path to ground instead of to the horn wire.

Whatever the case is, my “Debugging By Fire” approach damaged the slip ring contacts that allow you to have buttons on the steering wheel (Murdervan has the cruise control steering wheel buttons, but the actuator appears to have been taken out under the hood). I pushed a fix where I twisted a stripped end of wire very tightly around the spring plunger since the original wire attachment tabs had been melted off.

With the short now resolved, I tested that I in fact had dashboard and running lights again, and the horn worked. Again, I have no idea how these two problems were possibly inter-related, but here we are. This is what ghost hunting is all about, right?

Well, it’s certainly time to put this absolute disaster area together. But as I did so, I decided to go on an electrical binge and take care of an Annoying “Feels Good” thing that had remained unaddressed for a few weeks.

Up to this point, I had jumped the glow plug controller relay with a set of alligator clips hanging out of the doghouse/internal engine cover because I dug all of the fried electronics out of it before. So I’d jump in, connect the alligator clips, count to 10, and then disconnect them.

While I had the dashboard taken apart, I decided to make this hack permanent and run it to a button on the dashboard.

So to start, I wired one side of the contactor to the 12V feeder line coming from the battery. That means I just have to touch the other terminal to ground to throw the relay.

I ran this trigger wire up and around the engine cave, following other wiring harnesses, and into the dashboard area through some spare grommets.

I put this wire on the Magic Button that Murdervan came with. That’s right, it’s always had a Magic Button here. What did it do? Hell if I know, the wires ran somewhere underneath and just ended. I’m guessing it might have been a light switch or secret turbo boost/methanol injection button or something, since it was momentary and not latching. Whatever the case, it’s now the glow plug activation button.

The other side of the button was appended to the nearby main interior body ground.

And there we have it. I get in, push the button, count to 10, and let it go! This was the state I ended up selling Murdervan in – I never put in a new glow plug control module, and just explained it to the buyer who (as I mentioned, was familiar already with old Ford diesels) didn’t even bat an eye at it. I assume this is a common remedy for the dubious OEM electrical system anyway.