The Overhaul Design and Build Series, Part 5: “Don’t you have to ship this on Wednesday, dude?”

May 31, 2018 by the chuxxor in BattleBots 2018, Bots, Events, Overhaul 2

Yes, yes I do. STOP REMINDING ME OR YOU’RE HELPING MACHINE THINGS.

Well here we are, after the airing of the Overhaul vs. Sawblaze fight which will be on Science Channel’s website and other streaming service soon! I have a full writeup I need to do on the lead-in and post-match analysis for that one! That will come after the conclusion of the build series in this post.

We rejoin our heroe…. dumbasses in the 2nd-into-3rd week of March. March 21st was the latest ship date available for east coast teams in order for everything to make it there on time (or so we were told!?). Luckily, Overhaul was actually not in a bad position, at least compared to Season 2 when the extra long days really started kicking in. All I really had to do at this point was a final assembly, then work on remaining spare assemblies.

After the Week of #WeldingGoneWild, it was actually very easy to do a fitting of the whole front of the bot.

That’s about it. The only thing which wasn’t added in this photo was the clamp actuator itself.

I’m much more a fan of this design already. Once the whole thing is loosely assembled, there is a degree of “elastic averaging” *ahem* that goes on as all the bolts get tightened down, but after that, the arms are rock solid.

The drivetrain is being assembled more now. Check out the Markforged nylon engine timing chain style guides! The front chain was still a bit loose after this so (at the event) I ended up making a different set, to be shown.

The one on the right between the two motors is a little ridiculous. We were running so tight on time that I wasn’t going to get the #35 half-links of chain in on time, or at least too close to risk not being able to drive test. So I invented the stupidest possible chain -pincher for the intermediate drive chain – it was gonna wear out very fast with its profile, but would at least let me get some test driving in.

Closing up the other drive side. The design for serviceability that I did 2 years ago is really coming back to help me here. Remember, my team this year is scattered – Paige is working a real job across the country, Cynthia is occupied full-time and could only help on a limited basis with set-up operations, and I only had Allen’s help briefly with welding too. Most of the photos taken in this build series was work done by myself solely.

Here’s the first test-fitment of the entire bot with all hardware installed. I’m really liking all the design changes to the steel parts. In person, the new clamp and forks look better proportioned to the bot. At least to me, way better than OH2 for 2016.

(Fun game: See how many dumb project artifacts you can spot in the background of this and other photos. Chibi-Mikuvan currently resides under my desk.)

 

I spent an evening just pounding out spare parts for the incipient shipment. For one, I was short on drive motors now, but with a shipment of new HobbyKing Sk3 6374-192s waiting, I needed to key the shafts and secure the hardware. It was easier to pop the shafts out en masse and set up the mill properly.

This and more! I went through….. zero 2mm endmills, somehow. Still a harrowing operation.

It was now the weekend before, and I realized that I wasn’t going to be able to get my last round of waterjet-cut parts in time. These days, I get to be in the back of the line for MIT shop waterjetting – which I think is a very reasonable voluntary position to be in, as I have no official involvement any more with the institute. But dangit Sawblaze, you guys still do!

The electrical deck could conceivably just be drilled from a plate of aluminum, so that is what I ended up having to do. Out comes the TERRORISM. I just cut a chunk of 1/4″ aluminum plate out and started marking holes like high school Charles would have done, and he is always right.

Please do not ever, ever, ever do this. This is how you die. This photo is for illustrative purposes only and should never be attempted, building a robot is dangerous, etc. If you do, use the finest tooth blade you can get and have someone else pump WD-40 or cutting fluid constantly. Or you will die.

 

In the middle of the process. All the small holes are #4-40 tapped for Brushless Rages. Notice how I put six holes in some positions? This will be important later.

 

I’m loading up the bot with electrical deck hardware and wiring now. The shock mounts are in (and secured from the bottom) and some of the battery harness is visible.

The wiring for Overhaul this time was…… ad hoc, to say the least. I said I would dispense with the carefully cultivated greenhouse of busbars. The fanout occurs at the master switch terminals this time, with 8 gauge main leads splitting into multiple 12-gauge intermediate cables to the Brushless Rages. Single 6-AWG conductors handle the “fan-in” from the 4 batteries to the master switches.

The octopus taking shape, with ESCs installed.

Remember those 6-hole patterns? I had to temporarily use the 6-FET models for drive, keeping the 12-FETs for lifting and clamping.

What, are they magic or something? In actuality far underrated from their published specs?!

No, but I accidentally sold my entire product line – which is great – leaving ME with no remaining 12-FET units – which isn’t great. I had to dig into all my pre-production units here to even complete Overhaul at all. What is stock tracking even??

I wasn’t running off a cliff without a drone backpack, by the way. A month earlier, I had placed the assembly order for a new batch of Brushless Rages, but they wouldn’t get in until the Monday of the ship week and I was not taking any chances.

With the octopus wired in, the drive base is live for the first time. Check out the motor-on-a-stick I used to simulate having a clamp motor.

 

Overhaul prior to its first indoor test drive! At this point, I’d fight in 20 minutes if I had to. I think I was actually ahead of the curve here by a distressing amount.

 

I cleaned up and routed more wires into loom in order to un-nest the wiring some. This is inconceivably ugly to me, like a steaming fresh pile of partly-regurgitated dog squeeze smeared across a sidewalk by multiple unassuming passerby. I would never ship this in a consulting project. Yet some of y’all at the event said this was the cleanest wiring in a bot ever? What the actual hell is wrong with you?

(After seeing inside everyone’s bots, I’m not inclined to disagree. Sorry not sorry.)

 

Monday came, and hey! Look what’s here! More Brushless RageBridge units for all! I’d end up assembling 25 12-FET units and packing them with me to the event (not including my own spares, which were 4x for drive plus another 4x for spare overhead)

One of the put-off things was welding the wedges together beyond just tacking, so I spent much of Tuesday doing this. The plan was to take the tacked units to MIT to use one of the MIG welders I have access to and really smash them out quickly.  Using the bot itself as a welding jig made for expedient alignment of all my wooden dinosaur puzzle pieces.

DETHPLOW ™ was tacked together in the same fashion, by actually mounting all the pieces to the bot and locally squeezing with clamps.

For completion purposes, I fully TIG welded one set of pointy-wedges and mounted them on the bot in their final positions. TIG welding is truly the wrong technique to use for bitey pointy robot parts, in my opinion, since it takes so much time compared to MIG in an application where the sensitivity is not really reflected in the end product.

As I mentioned previously, it ended up pissing us off so much we immediately bought a MIG welder after we all got back from the event.

This, for instance, is DETHPLOW all MIG-welded together, a process which took only 15 minutes or so once it was jigged up. I designed all these pieces to be MIG-filled anyway. Here I am doing some TIG touchup on areas which I fell a little short with the wirefeed or missed, or had a gap that I couldn’t bridge as the fitup wasn’t 100% perfect. This is a fine state of affairs for me – blitzing and then fine tuning if needed.

One thing which occurred over the weekend was crate setup. I decided to just spent money this time to get an elegant and reusable SINGLE. PALLET. solution. As someone who’s had two double-pallet crates wrecked over two BattleBots seasons for reasons unknown, I decided I was much better off with a tall single pallet. U-Line came to the rescue with this 4′ x 4′ x 6′ tall snap-together crate,which I modified by adding some removable side-in shelving levels. The bot with its lift table and large tool chests/boxes was to fill the bottom floor, and more containerized accessory suitcases in the middle, along with the pictured Markforged gear – Markforged went ahead and lent me a 2nd printer for the event.

The top level would contain the loose large parts such as the frame rails and spare welded assemblies.

You know all those spare-everythings I was cutting and machining? They ended up in a tote which contained all the important mechanical bits of the bot. I’d prepped a full set of drive and lift motor spares, along with a few mor prepared motors. There was also enough cut tube sections to weld up a new clamp at the event if it came to be.

 

And here it is, Overhaul and all of its support equipment and tools plus spare parts, all ready to load up into….

 

Vantruck??????????????

 

THE PLOT THICKENS! During the week prior to shipment, a few of us NE builders came together to ally ourselves against the forces of time.

You see, Team Forge & Farm was planning to road trip across the country with their bot in tow. For a nominal fee of a few spare RageBridges, they were willing to also bring Overhaul along.

This effectively bought me an extra 4 days to work on the bot – in fact, the electrical work and spare welding photos you see were done after the 21st. On the Monday following shipdate, I picked up HUGE along the way and ended up in southern New Jersey.

 

…where, under the cover of darkness, we packed Earl’s truck up with our bots and his alike.

So… what’s in the crate? Well, there was still the lift cart and all of the already-completed spares, the printer, the mechanical tote, and other support equipment like the battery chargers and power supplies, and a few doen Ragebridges of various flavors. I handed off the radio suitcase and both of my event toolboxes off with the robot.

 

There were still a few kibbles I had to take care of after the bot went out but before I did. So, how do you jig up pieces for welding with you don’t have a robot???

You 3D print an imitation of the robot! This is an Onyx print with the same hole spacings and offsets as an Overhaul front frame rail. I used it to tack the pieces together quickly (as to not melt anything) before removing them.

And with that, the build of Overhaul 2 for the new BattleBots concludes. To be entirely honest, I found this build season pretty stress-free, largely because I didn’t have to build a new bot from scratch and was making only well-scoped changes I had anticipated in advance. In the position I am in now working on a new company with my friends, I don’t think I could have pulled off the record build of OH2 for Season 2 in 2016. My (and my friends’) experiences in this build and competition season of BB – without going into NDA details of the show – has really shown me that I have to move back to a “When it’s ready” format like I had to do during my busiest times at MIT trying to vaguely graduate on time. I have a lot of thoughts on the show as a whole and the direction I’d like to move in (and the show should/shouldn’t move in) that are much better reserved until after the entire show airs.

But for now, hang out here a bit for the event report and a SawBlaze vs. Overhaul post-match!

And now a word from our sponsors!

HobbyKing – Somehow still loves me and enthusiastically supportive of my efforts to abuse R/C model parts for unintended applications! I’m running a HobbyKing radio (9XR Pro) and batteries (Graphene 6000 65C 6S packs, times 4), motors (SK3 63-series), BECs, and a whole lot of wiring and connectors. Not to mention the Reaktor battery chargers and who knows what other HK kibbles have made it into my tools and accessories. I like to think that I had a large role to play in the commoditization of silly electric vehicles using R/C parts also.

MarkForged – from the days when I knew 50% of the company to today when half the new marketing and sales staff go “Who is…. Professor Charles?”, they’ve provided me with high-strength printed parts for a lot of different projects, both on this site and off. Introducing them to the robot fighting community via Jamison’s and my efforts pretty much made MarkForged printed-unibodies the competitive standard in the 1 and 3lb classes, and trying to find new niches in the bigger weight classes is one of my goals. This time, Overhaul’s drive wheel hubs and casting molds are printed from Onyx, and there are also plenty of smaller chain glides and tensioners and accessory parts.

SSAB – I find it interesting that the company’s full name is SSAB AB – Svenskt Stål AB AB, or Swedish Steel Company Company, but these days the lettering is the whole company name so that’s actually not true. This year, I’m working with one of their North America regional distributors and all of the armor steel on Overhaul – including the entire clamp arm, top plates, and new wedgelets and DETHPLOW™ are Hardox 450. Hardox is the easily-obtained ARx00 of Europe and other regions worldwide, and bots overseas have used it for years, but it’s not really had a foothold here in our scene compared to the number of AR-spec steel products in the US. So hopefully I can help with advancing that brand too!

BaneBots – I was called an edgelord for even thinking about using P80 gearboxes in a modern Battlebot. I always thought they were under-loved after the FIRST Robotics Competition quality issues of the late noughties, and had used them otherwise in several projects including consulting projects before shoving shorty Ampflow motors into them for Overhaul 1 in 2015. And you know what!? They’re great! Overhaul 2 ran them exclusively for Season 2, and now for Season 3, OH is sporting the new BB220 series with much stronger planetary output stages for the lifter.

Equals Zero Designs – Yeah, umm, I don’t know much about those assclowns.