Finishing Battery Boxes and Feet

I’ve been busy the last few days and not had much time for building. I did get to work on the ankles and legs a little bit more and I think I’m pretty much done, minus one small piece that I need to buy something for to fix.

I’ve mentioned this before, but now that the ankles are back attached the to the feet it was hard to slip the battery boxes over the motors.

The right box went on no problem but I had to make a small adjustment to the left one one and open up the hole a tad. I also had to shave a little bit more off the top of one of the motors, to get the box to sit flush with the foot.

The boxes are really springy with the hoses attached and and there is no way the two screws that are supposed to push fit into the slots will hold the boxes flush to the feet. At least I couldn’t get it to work satisfactorily.

I think I’m going to have to come up with another method of securing the boxes, and will probably use some super strong magnets. That way I don’t need to fiddle with setting screws in tight spaces.

I ended the evening with attaching the legs to the ankles. I used pan head bolts, lock washers and fender washers instead of the countersink Phillips. This will hopefully give them more substance and grip on the legs. The 10-24 Phillips work their way loose way to easy even with thread lock glue, and I’ve had a few wiggle loose during a single outing and sheer off. If this fix doesn’t work I’ll knock out the 10-24 threaded inserts in the legs and use 1/4-20’s bolts instead.

I’m going to try and paint the bolts and washers white to hopefully hide them a bit.

That just leave the battery harnesses and back foot strips to silicon in place, and of course the magnets to hold the boxes.

Posted by Chris on December 10th, 2007 in Feet | No Comments

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Re-assembling the Bits

I was going to add a few more coats of paint to the skins today, but on close inspection in the daylight they looked fine. A lot of the dust spots I was seeing yesterday just rubbed off with my finger now that the paint has had time to dry. I’m going to leave it a few more days before I attempt to remove the masking tape, as it’s been pretty cold and I’m not sure how the paint cures in this sort of weather.

I’ve decided to re-assembling R2. Started off with something easy – the center ankle as it’s relatively simple and self contained. I need to get him back on 3 legs to start laying out the electronics again. I’m probably going to move things around a bit, for example I know the speed controller can’t stay where I had it on the back mounting plate as it now hits the skins. It may end up on the back side of the plate or somewhere else internally. I also want to build in some sort of switch and circuit to allow me to charge the batteries in place rather than having to remove the cables each time to clip the charger on.

I’ve been paranoid all week that I’m going to ding or mark the paint, and tonight I had to moved passed that. Right off the bat there was no avoiding dirty fingerprint from the grease when handling the new white paint, plus I scratched a some paint off trying to get the ankle to fit back in the foot shell slot. I really should have filed down the metal parts a long time ago to compensate for the added paint – but I didn’t. I’m sure it going to wear off in this spot anyway, but don’t ya hate it when something like this happens?

I’m glad now that I didn’t get things powder-coated and at least I can touch it things up myself if I need to.

I’m going to have to keep an eye on the foot shells as they’re steel and prone to rust, especially where I live on the coast. It’s ironic that one of the reasons I went with an aluminum droid was because wood warps so easily here, even when sealed, and now here I am worrying about rust from the salt air. I may just grease up this area when I get around to weathering him.

I also noticed that nearly all of my ankle cylinders are scratched up and should really be repainted, but I’m not going to do it this time around.

I used silicon to attach the foot strips to the foot shell. I should probably tap and screw them on, but I’m feeling lazy and really want to see this done. I roughed up the two surfaces and taped on the strip. I’ll probably know tomorrow if it works.

I think it looks pretty cool all put together don’t you think?

One last thing while I remember, don’t forget to use screw Loctite or something similar. I missed a few screws in the feet before C4 and lost nearly all of them by the end of the week.

Posted by Chris on November 30th, 2007 in Feet, Finish/Paint, General, Legs | No Comments

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Hiding Drive Wires

Here’s another retroactive post about something I worked on a few months ago.

One of the challenges is passing the drive wires that goes from the ankle into the foot shell. Some people use the totally hidden/invisible method where slots are cut in the side of the ankle and foot shell very close to the bolt. Here’s an example of Wayne O’s setup using this method.

Space is tight and things have to be perfectly aligned or you run the risk of chopping the wires when the ankle pivots. It’s also virtually impossible to add grommets so over time my worry is that the wire may wear. edit 9/7/07 – Wayne just informed me that his setup above has been working fine for over a year and half without any problems or wear and tear.

I was on a time crunch and not sure if I was up to marking and cutting such precise slots, so I opted for the more conventional method of drilling holes in the foot shell just behind the ankle and corresponding hole in bottom of the ankle.

My wires are pretty think and by my calculation I needed a chunky grommet, but I couldn’t find anything suitable so had to improvise. Instead I used a short length of opaque tubing which passes through from the ankle into the leg. Not only does it protecting the wires it also hide them.

This is the inside of the Ankle

And the Foot Shell

Tube passing from the ankle into the foot shell

I also used the same hose in the top of the legs/shoulder to protect the wire as it passes into the body.

Posted by Chris on August 6th, 2007 in Electronics, Feet, Legs | 2 Comments

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