Mounting the Radar Eye to the dome

I don't care if I measure something a thousand times because it's a sure bet that something is still going to be off. It's my weakness and can be rather discouraging at times.

Yesterday I made a clear template of my radar eye out of clear transparent inkjet film that can be used in making transparencies. It looked very good after I cut it out, marked the holes and taped it to the radar eye. My plan was to position it on the dome and then tape the transparency on the dome and mark the places to drill.

The plan started getting a little suspicious when I realized how rounded the dome and radar eye were. This wasn't a flat template. But after a couple hours of screwing around, I finally got to that point where I just wanted to get it done. I figured that there was plenty of room to oversize the holes to position the radar eye if there were problems.

It was pretty close but of course I had to make a few adjustments. Now I'll cut a large hole in the dome that will give me access to the eye lens in the dome.

While working with the dome, I noticed a couple of the panels I glued on (last month) with the goop were loose. That goop is really not worth a darn. Someone mentioned using clear silicone adhesive so maybe I'll try that for the remaining panels. I do want them accessible if I need to remove them for refinishing or whatnot so that's why I don't use permanent epoxy or JB Weld.

Modified skin blocks

Well as I mentioned in a previous post, the skin blocks I received were not what I wanted for my droid. I want to remove my droid's skins without having to remove the legs.

So I came up with a technique where small 6/32 bolts would protrude through the front of the mounts so you can lay the skins over them and thread a small nut and lock washer over them tightened with a small wrench. This can easily be accomplished with the legs attached.

My first attempt was a lesson as I broke the tap off on my first try. And it was a bad break where I couldn't thread it back out. So the lesson taught me to drill out much of the back material of the skin mount so I wouldn't need to tap so deep. Because the 6 NC32 tap I used is pretty thin and breaks easy.

The first step is to re-drill the threaded holes in the skin mounting block with the drill bit that comes with the 6 NC 32 tap. Going all the way through the block shows you where to drill the material in the backside of the mount with your large drill bit. I think using cutting oil and a drill press is a must. The drill press insures a nice straight bore. And the depth gauge on my press gave me uniform depth which was nice.

After drilling at least 3/4 of the blocks back material, new threads were cut with the tap. And then I threaded 1/2" 6/32 bolts into the blocks. I used the small bolts that were in my vex robotics hardware. After threading them into the mounting blocks, I mixed up a batch of epoxy to pour over the heads of the bolts in the back. The epoxy is just extra insurance to keep them from moving at all while removing the nuts holding the skins. Probably overkill but it only took a few minutes and I had the epoxy on hand.

I drilled the holes in my skins and made the holes a little oversize so the bolt threads wouldn't be stressed out while removing and attaching the skins. The skins went on nice and the new setup looks similar to the original .040 screws. I'm glad I didn't use a thumbscrew as that would have looked more obvious.

Also I will only use the mounting blocks above and directly below the shoulder hub. The lower ones I don't feel need to be attached to the skins even though they will be on the frame.

Skins to frame setback

I patiently measured and drilled holes in the aluminum skins to attach to the new frame to skin hardware I received. After attaching the skins a thought hit me like a ton of bricks.. The only way I will be able to remove these skins is to first remove the legs of R2 because the hub is positioned over the screws. That doesn't make any sense to me as removing the legs is a bit of work. And of course the legs will have wiring so that will also need to be disconnected.

If I was at an event with R2 and needed to get inside the droid for troubleshooting, I could only go in through the dome unless I remove the legs. So now I'm thinking about re-tapping the holes in the new skin mounting hardware to accommodate small thumb screws. I need to really think this through first.

Back to building again

After being gone for almost 4 weeks on an extended vacation it's good to be home again. And good to be back on the R2 project. A few parts came in the mail while I was gone and last night I started experimenting with the new skin snaps that fit the JAG frame I own. The difficult part of these snaps is measuring and drilling the holes in the skins.

Last night I fabricated a piece that will hopefully help line up and drill holes in the skins. I drilled one of the top skin holes and it seemed a hair off but not too bad. The middle set and bottom sets will need more thought before drilling.

I also received a sweet set of C3PO arm pistons from Jerry C. They will look nice on C3PO when I get enough time to install them. That's one area of my C3PO that's currently not so hot.