Ok, it's Sunday night and, as promised, here is another update!
I revised the blast door setup yet again, in an attempt to make it even simpler. Trying to synchronize two servos
at varying speeds proved more difficult than I thought, and produced inconsistent results at best. So I have returned
to using just one servo, and having it control both rollers. Since I already have one servo connected directly to the smaller
roller, I will just need to add a small pulley to it, and a long o-ring to attach the larger roller. The speed difference will be
accounted for in the pulley sizes.
Another alteration is to simplify the path that the door has to take. I had originally intended for the door to travel towards
the front, and make a 90° turn into the hard drive cage where the rollers were located. That was adding too much drag, and the
door was getting caught up at the turn. So my solution is to hack away part of the hard drive cage and mount the roller
closer to the window, thus shortening the path.
So here is the roller, and approximately where it will be relocated to:
After cutting away part of the hard drive cage, I took two pieces of aluminum angle bar and sandwiched
them together, with the HD cage in the middle.
Using pop rivets in a staggered fashion, I fastened them together. This will provide a good solid mount for
the cut-down roller holder.
Then I pop-riveted the holder into place, utilizing the holes I drilled prior to riveting down the angle pieces.
Believe it or not, I actually thought ahead for once!
Once I get the second roller in place, I can measure the distance between the two and see how large an o-ring or belt I will need.