Tuesday, August 11, 2009

Cut Vertical Rail (Twice)

Tonight I cut the vertical rail that helps lock in R2's 36 degree tilt. I had such a good time doing it, I did it twice. Why? Well, here's the long-winded explanation.

Due to my not concentrating on what I was doing, I ended up cutting and drilling the mirror image of the vertical rail that I wanted. This would have been just as usable as the one I ended up recutting, but I prefer to have droid #2 match droid #1 as much as possible.

The problem occurred because I laid some of the angle iron back-to-back with an old rail that already had the holes drilled at the correct heights. Using this old rail as a template for the holes resulted in the drilling of the holes on the opposite side of the rail that I wanted. No big deal, I was able to take that mirror image rail, and re-mirror it onto yet another rail, and all was well. As an aside to an aside, the reason I'm not using the original template rail on droid #2 is that I did not leave enough room for a socket wrench to fit into the area to loosen and tighten bolts. Incidentally, the vertical rail is 1.25" on each side, and 1/8" thick.

Okay, on to today's activities.

First up, cutting the rail to the correct length with the jigsaw. The distance is just a little longer than from the base of the frame to the electrical pipe that helps hold the legs together.

Next, I used my new accidental mirror template rail as a guide to show where to drill the 1/2" holes for the U-bolt.

The U-bolt fits in perfectly.

The final hole is at the bottom of the rail, where one of the 3/8" bolts that goes through the center leg will also go through the vertical rail.

In the process, I created a weird science fiction worm of some sort.

Time for the fit on the droid. Looking good!

Here is a close-up of the bottom hole, and how one of the bolts that helps secure the center leg to the bottom rails also goes through the vertical rail.

Here is a close-up of the U-bolt passing through the vertical rail.

When the droid is tilted at 36 degrees, tightening this bolt down helps lock down the angle. I will also file a flat spot on the pipe, so that when the rail leans on the pipe, it is less likely to allow the pipe to roll about. This has worked well on droid #1 for a couple of years now, and Mike Senna's droid has been running over twice as long this way, so I'm pretty confident in this approach.

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