A while ago I posted a thread asking for help on building a revolving stage for a production of Jekyll and Hyde. These are some things I've learned:
1. Give yourself enough time. My high school's admin and various teachers were opposed to it because the revolve would impede the complete closure of some of the travelers. As a result, I couldn't get the thing done until a week before opening night.
2. Don't design anything around cost. Sure its cool to have a budget, but don't cut corners. I bought dumb casters partially because it makes the stage more diverse in its capabilities, but also because they were cheaper. BIG MISTAKE. Once we got the thing able to spin, all was well, but once we put a set on it, it made the loudest squeaking and groaning imaginable. We had to jack the whole thing (All 379 square feet of it) up and crawl under with a few cans of WD-40.
3. NEVER USE PARTICLE BOARD!!! Probably the worst stuff to use when building a multi-layered deck. I used two layers at 5/8" thick(glued and screwed) except that the one inch screws we tried to use stripped the wood every time we ran them in. another thing I didn't consider about particle board: it has a rough and a smooth side. I accidentally put the rough side down on the bottom layer, which just added to the rumble as at slid over the casters. Why did I use particle board? Because the good stuff was 4 dollars more per sheet. don't cut cost.
4. Once again, I cut costs. I mounted the casters to 2x6 boards, which i then adhered to the stage (wheels up). unfortunately, the top plate of the casters were 6" (and we all know that a 2x6 is really 1.5 x 5.5) I could only put two screws into the casters, but figured since the axle wasn't hanging over the edge of the board I'd be fine. We lost 12 wheels when positioning the deck. Had to jack up again and crawl under there.
5. Build your revolve in sections. I simply glued the whole thing together in one giant piece (24'x24'), slid part of it off the edge of the apron and cut out a circle (it took 50 people to shove it across the stage floor) I then had to get everyone to shove it off to the wings while I mounted the boards with the casters, then had to get everyone to shove the thing on top of the casters. BIG MISTAKE... one of the 12' boards holding the casters got ripped out of the stage and caught up under the deck as we tried to slide it on. Had I built the thing in sections and assembled on top of the casters, I'd have been breathing a lot easier.
6. And last but most important...DO YOUR FREAKIN' MATH!!!!! the casters I got had a load limit of 100 pounds. I estimate the deck to weigh 1600 pounds. (assuming 50lbs per sheet of plywood, 36 sheets would be 1800, and I guess I cut off 200 while cutting out the circle). I used 69 casters, so 1400 divided by 69 is 23 lbs per caster distributed over the entire revolve. Add det to that, (a giant pyramid like thing, more heavy stuff etc etc.) and bam, my casters are overloaded, or getting close to it.
Lessons learned, though. Sooner or later I'm sure i'll laugh at some strapping young man making the same mistakes as I just did.