Tuesday, June 23, 2009

Battery Boxes for Sale, Council Approved.

I have just completed my 3rd run of Battery Boxes. I've got 12 pairs to sell.

Construction: The side walls, top and bottom are made of expanded cell PVC sheet (1/4” and 1/8"). The end pieces are made of PVC pipe, sliced in half. All joints are glued heavily with PVC cement. They are sturdy enough to stand on.

I have not put any holes in the front for the cables or the sides for mounting to the feet. If you are putting motors inside of them, the PVC is easy to work with. You'll have to check to see which motors are compatible with the 1/4" sidewalls and the reduced width of 2.9". I haven't installed NPC motors in these, but some of the previous buyers probably have at this point. I can check.

Specs: These boxes are to club specifications with one exception. The width of the boxes is about .1" shy of the 3.00" blueprints. PVC pipe with an exact 3" outside diameter is difficult, if not impossible to find.

Finishing: The boxes have been finish sanded down to 320 grit. All the joints are smooth and clean. They are almost ready for primer. They may need a bit of touch up sanding here or there.

Price: $85 a pair plus shipping. Email me at mccormick@csus.edu for exact shipping costs, and paypal that email address to place your order. I should be able to get them shipped out with a day or two of getting the order.

Sunday, June 14, 2009


Went to the RoboGames in San Francisco today (and the Maker Fair a few weeks back), and hung out with Chris James for a good while. His droid is an amazing piece of work, and his blog has been a huge source of helpful information to me from the start. It was great to get a close up look at it. Chris got me and my boy, Max, into the pit area at the RoboGames by assuring the event staff repeatedly that we were with him. And he even handed me the remote control to drive his R2 around a few times. That showed some trust. I know every bit of agonizing work that has gone into his machine, so I took it very easy.

One Year Progress Report

Despite the lack of activity here on the blog, I've been working on it quite a bit lately. I got the styrene skins all glued on. Getting the inner skin attached to the frame is tricky. Turns out that even though lots of materials experts have opinions about the best adhesive for styrene to wood, none of them seem to know what they're talking about. I bought 15 or 20 different kinds of glue, ran extensive tests on all of them until I found something called Griptonite by Devcon. It's more or less a superglue, but it is a bit thicker than most, and there's something in it that dissolves the styrene a bit to make it bond well. I bought up every tube within a 50 mile radius--TAP Plastics, and attached the inner skin bit by bit. Alignment and drying times were hard, but I got it figured out with some work. Then I got the outer layers glued on. Here I could use standard styrene cement--Testors--and it works fine. The results are good. Here's the whole droid, more or less with a lot of the major assemblies fitted on. I have lots more parts on the bench, but I'm not ready to mount them.

I've also got my Rockler bearing mounted here with the dome ring loose mounted. Lots more work to do. More later.