dome motor mount

I got a dome motor and mount from one of the folks on astromech, but it turns out the current crop of COM8 budged frames doesn't have the drill holes for it. I went back and forth with a couple folks until we determined that nope, the holes totally aren't there. Kind of a bummer, but it wasn't too bad, as someone dug up a picture of where the holes ought to go, and so I was able to drill and countersink them tonight. A quick smoke test to the motor, and I have a spinning rockler bearing:

Fits nice and snug too.

Actually, speaking of smoke tests, I powered it with a nice new 12V/7Ah SLA battery I got from the Radio Shack down the street. The bad news is, it's going out of business. The good news? 3 of those batteries for $1.75 each. Oh, heck yes. They may not drive the wheel motors as well as 24Vs, but they'll take care of the rest plenty fine.

Anyway, I should be getting dimensions on the aluminum skins soon, specifically the back maintenance hatch. I will be getting the actual dome motor controller before long as well, so that will be nice. I should have sounds and dome spinning working in time for Planet ComiCon.

PADAWAN stage one: control and sound

Been a quiet week, mostly because of this stupid cold. I did manage to read up on the PADAWAN control system, and decided to go with it as it seemed a fairly simple way to get started. I dug out my old Arduino UNO, got a Lynxmotion wireless PS2 controller with a "level select", and an MP3 trigger board with a micro SD card.

First step: connect the PS2 to the arduino (the box on the left is the receiver. The level shifter is the circuit board it's plugged into).

Next up, a quick test to make sure we are getting the signals across. I load the arduino with a test program for the PS2 interface and give it a whirl:

At first I was getting garbage in the Serial Monitor, then I found out that the test program expected to run at 57.6Kbaud. I changed the Monitor's baud rate, and voila:

We are in business.

Next up was the MP3 trigger. It takes, as I said, a micro SD card to hold the mps. I downloaded the "official" sound set from astromech, as well as the PADAWAN sketch. The instructions say to copy the MP3s over one at a time so that they appear in order on the file, but when I did that, they were all hosed up. Some triggers played, some didn't. Nearly none of the triggers matched up to what they were meant to play.

A quick call for help on astromech revealed that OSX is a bit bad about this. I chucked the micro SD card into a Windows box, and lo and behold: a lot of metafiles created by OSX were throwing the system off. I deleted everything but the actual MP3s, loaded it back up, and was in business.

(Pictured: MP3 trigger board in red hooked to an amplified speaker for testing)

So, lessons learned:

• When running a sketch that sends output to the serial monitor, always be sure to double-check the baud.
• When copying files to an SD card where you really, really don't want anything on there but those exact files, avoid OSX. Maybe go with Windows or Linux.

Anyway, hopefully I'll feel good enough this week to get back to 3-D printing. In the meantime, I've got a drive motor and controller on the way, and the Radio Shack nearby is going out of business. I saw some SLA batteries there going cheap. Hmm...

Oh! Forgot to mention: Wednesday marked two months down, ten to go. I think I'm making good time, knock wood.

COM8 Frame and more

Friday was a good day for me. My COM8 frame showed up, as did the dome gear for the motorized rotation, and the first part of my PADAWAN automation system (a PS2 extension cable).

COM8's frames tend to come in "pizza boxes". They flat pack down but have a LOT of stuff in them:

Fortunately, they do include the instructions:

First, the top ring gets the two side panels where the legs go:

Then the middle ring gets attached to the bottom of those side panels.

Up at the top, this support bar gets mounted across the middle:

Note the circle cut out here in the middle: this is for a slip ring, which if you don't know is a mechanism that legs you hook wires to an object that spins. The slip ring rotates while keeping the connection and not letting your wires get all wound up in the process.

One slight flaw: it appears one of the holes wasn't drilled quite deep enough. I'll have to get a shorter screw.

Next up is the front assembly, with the three "shelves". The top is for the large data port, the other two are where the utility arms go.

Finally, the bottom disc is added, with 8 pipes to support it (also note the two long support bars in the back):

(The thing in the lower left-hand corner, btw, is the middle leg plate. That gets added when it's leg time.)

Anyway, off to the store to pick up some smaller screws for that one hole. While I was there, however, I came across these:

3/4 inch vinyl pads, just the right size for the dome buttons.

Anyway, while the paitn was drying on those, I broke out the dome gear and the rockler bearing and started to work on them. Turns out I hadn't drilled all the mounting holes in the outer ring yet, so I had to do that. And of course after that I had to disassemble and clean the rockler all over again.

Lesson learned:

• Drill ALL the holes in the rockler bearing, AND tap the holes for the outer ring, BEFORE you replace the bearings.

 Okay. So once that was all done, I put the rockler together, then I bolted the dome gear to it. After that I took the whole thing and bolted it down to the frame where it fit like a glove:

Next stage was to drop the dome ring over the bolts (I used 2" ones to get enough clearance, and 3 nuts for enough space that the ring could spin without disturbing the main body):

After that, it was just a question of mounting the dome to the bolts and using a couple of wingnuts to keep it in place.

After that, I broke out the bondo and started working on the legs. They and the horseshoes were very uneven, so I went ahead and gave them both heavy work on the edges:

I'll sand them down later, but for now I'm just letting them cure up nicely. Besides, all things considered, I think I've done enough this weekend:

(And that's fighting a cold!)

Booster covers: after

So I gave the booster covers a nice Krider blue to go with the rest of the droid after giving them a good sand-down at the makerspace. Now it's time to add the silver touches. First, masking time:

(I'm trying Frog Tape to see how good it does for paint masking) A quick dose of Valspar silver, and voila:

Pretty nice. A little touching up here and there, and I should be good.

Today is a leg day

So the used legs I got from the junkyard showed up. I was pretty excited, as you can probably imagine. I got the wooden leg assemblies, the horsehshoes for the top, resin booster covers and booster pistons. They even had the "fat ankles" attached. So this will save me some time -- not to mention money.

That being said, I was later informed that bailing out of the leg run I had previously signed up for in favor of picking up these instead is frowned upon in the R2 club. It goes against the whole build-your-own ethos, but also it's best not to bail on a build run unless it's like financial hardship or something like that. So, now I know:

Lesson Learned:

• Don't bail out of a product run unless you have to

 Still, I've got the legs now, and they're all right. They've been glued together, and some smoothing has been done, but it's going to take a lot more. Still, this is entirely workable, and I can't wait to make it happen.

Here is one of the legs with the booster stuff, horseshoe, and the shoulder buttons and hydraulic I printed and painted a while back:

As you can see, the booster covers are going to need some serious trimming and painting and whatnot. I'll take them by the shop soon.

Yet another utility arm

So a new version of the utility arm has been released, this one a stationary version. I gave it a go and it came out looking all right. Certainly a lot smoother:

They come with a box that you mount the arm in (you can see mounting slots in the upper part of the arm above). I haven't printed those yet, so I'll have to see how they look.

Some painting

So now that the dome is done, it's nice to rest a little. Mostly I'm just working on paint and prep:

The four main bits of the battery box clips

The ankle wedges

The ankle details (I did paint them earlier, but only recently noticed the blue tips)