I guess I’ll count the wheelmotor co-updates for TB4.5 also. With Motorama now only 3.5 weeks (!!!?) away, it’s time to get crankin’ on SP1.

Some revision work on the “EBays” was needed since I wasn’t going to use the Dimension Engineering ESC for drive any more. Unfortunately, that meant going back to the 883s or spending hectobucks on another controller solution (brewing in-house was another option, but I didn’t quite work up enough balls to do it. Plus the 883s have real transistors anyway). With some wrangling and wiggling of components, I was able to fit all the control electronics on one side – finally, a true electronics bay. The arm controller has to stand vertically, but that isn’t an issue. The other E-Bay contains the battery, power distribution, and master power switch.

The shovage of components on the left side is incredibly tight. Tight enough such that I tried using the wire and cable routing feature of Inventor to see if I can fit all the connections. It should be fine, but I’ll have to build it IRL anyway. Plenty of space for disaster!

Here are the frame rails cut out and positioned, with various components in place. I hadn’t “precision miter-sawed” in a long time, so it took a few practice cuts before I was able to get things within .005 on the first try again. Also, the saw fence seems to be losing some accuracy near the blade, as a few cuts were a bit warped. The gears were rather noisy.
Shortened lifespan. That’s what I get for royally abusing a tool (it’s launched its fair share of stock across the garage). I didn’t get a chance to repair stuff before I left for MITland again, though. It’ll be fine for 2x4s.

Frame rails marked out with calipers and sharpie. UHMW drills, threads, and generally machines very quickly, so I anticipate that this assembly will be done with half a day’s work. Problem: Getting all that Sharpie…errr, layout fluid… off the UHMW. It’s set for a few days, so rubbing alcohol doesn’t affect it any more. I’d use acetone, but the last time I did that, it left the sharpied areas with a pink hue.

So, either pink splotches or random-ass sharpie splotches… Hmm. I’ll figure something out. I could just color the whole bot black with sharpie and have one hell of a solvent trip in the process.

Tomorrow: Working on the arm gearbox, getting some of those components done. Order some aluminum plate, get on the waterjet and GIANT LAZER at the Media Lab and cut out the redesigned EBay plates and the top and bottom chassis covers.

Bot forth!

I’m seriously about to give this thing a developmental codename, like “Fluffy” or something, instead of having to type TB4.5MCESP1 the whole time. That’s longer than most bot full names.

Anyways, in a bout of insanity (I’m some times prone to having these… some argue most of the time), I downloaded the 3D models of every type of screw or other random hardware I would need on the bot… and threw it all onto the main assembly. It ended up at almost 420 individual resolved parts. The Chuxx0rbox was not happy.

No, this does not mean I downloaded 300 parts – just that a certain #10-24 screw model was used over 130 times. Yes, there are about that many screws holding the bot together. Throw in a few #6s, 1/4″ bolts, and so on…

So the finished model was probably missing only wires, duct tape, and Loctite. The wires could have been taken care of by Inventor’s automatic wiring harness routing software. I should ask for a duct tape option on future Inventor releases.

The final weight was 12.3 pounds.

Yes, 12.3 pounds. How on earth could a UHMW box possibly weigh that much? I had a hard time believing it also until I broke down each of the subassemblies and checked their contents.

• The UHMW frame itself only weighs 1.3 pounds. That’sjust fine. I wouldn’t want it to be any less.
• Two of the drive gearboxes combined weigh about 1.6 pounds. That’s very reasonable for full 550 type motors in metal mounts with metal gears.
• The entire arm assembly weighs 2.7 pounds, wedges, motors, and all. Not unreasonable for a weapon assembly.
• The electronics bays in total weigh about 1.5 pounds, including batteries.
• The two square feet of Garolite that form the top and bottom weigh .6 pounds.
• It turned out that I added about 1.2 pounds of screws.

Okay, so, what the deuce makes up the rest? The giant metal flaps that are the wedges. Especially the side ones – if I ditch those, I save about 1.25 pounds which could go towards armoring the rest of the very exposed and vulnerable UHMW.

So it looks like I’m going to keep working on a better front wedge idea.

The most logical way would be to taper a corner of the flat material that will form the wedges and form an angled surface towards the side. Kind of like TB4 back in 2006.

The problem that prevents me from immediately going with this idea is the fact that the D*C wedge was 1/16″ sign aluminum, which could have been a 5000 series squishy alloy for all I know (Bending that was hard without a good, giant vise, which I did not have at the time). And here I want to use full quarter inch metal. Clearly, making the bend is going to be an incredible feat.

If I can manage it, though, the results don’t look half bad.

Actually, it looks dead sexy.

Using this design with properly worked 2024 or 7075 (either alloy, I assume, would need annealing to bring them to a formable state, especially 7075) would round out the perfect bot upgrade – harder, better, faster, stronger.

Harder materials on armor surfaces, better attachment to the chassis, faster AND stronger arm and drivetrain. Great, now I’ll go play some Daft Punk. Anyway, using “good” alloys for exterior bashing surfaces might not be worth it. The same effect could be achieved by layering some thin spring steel over a more inexpensive and common alloy like 6061.

I’ve updated the TB4.5 project page to reflect the upcoming revisions.

Oh, and while the bot was in “fully decked out mode”, I made sure to mess around with Inventor’s rendering engine which was plucked from 3DStudio after Autodesk bought Discreet.

When a renderer is good, it makes even the shittiest newbie attempt at using it look really freakin’ awesome. So here’s a TB4.5MCESP1 half-assed rendering. I had some issues with some of the lighting as the completely flooded wedges and sides attest to. A good 3D imaging artist could probably make it indistinguishable from the real bot, but there’s a reason I’m not an artist – I get to make the bot. Full-size image is 1600×1200.

Bot on!