PZT Construction v3

I immediately noticed some problems while using version 2.

#1 getting the dome on and off the wheels to the trusses was a PITA. While pushing the dome off the wheels, screws heads protruding from the wheel running surface, a steel plate on the underside of the dome lip), would scrape the wheels quite badly. I could imagine eventual wheel damage occurring. Getting back on, it was impossible to lift the entire dome at once onto the track, so I resorted to lifting one end partially onto the wheels, then I would go over to the other side and try to lift it. Of course as soon as I would lift the low end, the high end would easily slip off the wheels back down onto the table (with a thud). This could repeat several times until the magic amount of force was exerted. Very annoying in the early morning hours.

#2 Pushing the dome across the beams was very scary without guard rails, especially when you can't see all the contact points at once. So moving the "rolling" the dome was a fairly slow and careful operation. Not good for a cranky, sleep deprived astronomer.

So while my carpentry inclined brother in law was visiting we had a go at fixing these things. Here is the result.

The dome now slides ~ 36" on levered 1x6 boards with stops and rails.

That's a 2"x8" tacked on to the twin 2x4's from underneath, probably overkill, but hey.

We straightened out the uprights and staked them into the ground., much better than before.

Slight cutout of the board allows dome lip to slide down the middle of the 1"x6". The side guard rail is a strip of 1"x1.5" pine, cheap and easy.

Dome hovering over top of wheels. The left end of 1"x6" deck boards are held down by the small metal hooks (with safety catch). Undoing the hooks drops the dome down, after which the 4 lever boards are simply pulled out from under the lip. The can be stored right on the table out of the way of dome rotation. The reverse, shove board into slot, lever up, pin hook, is done to get the dome up

Close up of retaining hook. In order to lever the dome up simply force down on the deck board and slide the hook into the eye.

Close up of other retaining hook and safety stop.

Close up of the lever action in the center runners.