Periaktoi plumb/square issue

[jcfalc01]

We have just completed the basic construction of 8 periaktois that are 4 ft on a side and 16 ft high. The bottom 8 ft is constructed of 2x4 lumber and 3/8 in plywood while the top 8 ft is 1x3 lumber with luan. We've got them on 2 ft black pipe in the center for the pivot point and of course in-line casters. On first install, the units are not plumb and square. Any help in suggesting how to rectify this situation. We tried to square based on the 4x8 3/8 ply. Not sure my crew did that correctly. Anyway, any suggestions? We've got three weeks before the show opens. Thanks!

 

[SHARYNF]

Probably some of the more experienced set builders will have more suggestions, but usually it is done by making a square box and using this so get the triangle pieces square before adding the braces
This might help


Periaktoi

Getting them to rotate with no gaps is typically the problem, most people seem to give up on the center pole and just have then on casters and manually turn them

Blue Room technical forum > Problems with periaktoi

Here are some other suggestions re turning them

Community Theater Green Room Discussion Board: Periaktoi

Sharyn

 

[ajb]

Is your floor nice and flat? If the bottom is not square to the sides you can shim the casters to get the unit plumb, but this only works on a smooth, level floor. If your floor is an issue, you'll need to build up a level deck (could just be a shimmed plate of 3/4" ply or MDF just big enough for the casters to run on) to compensate.

If the edges of the units themselves are wonky, you probably will need to do some amount of surgery. How did you build them?

 

[SHARYNF]

My guess is that when they are placed next to one another they don't line up and you have all sorts of gaps?

If the edges are straight then you could look at a support system top and bottom if the problem is as I am guessing the gap is expanding toward the top?

Sharyn

 

[jcfalc01]

We are really close. The floor issue could be one of the culprits. The 2x lumber not being true is likely the other. This afternoon, I'm going to take one of the two problem units down and change the structure a bit. Our current structure is much like that posted above by SHARYNF (we did not use boxes).

What I'm going to try is to take the edge 2x4s and move them about 2 inches in from each edge for each 4x8 sheet. This will double the 2x4 lumber but what it does is allow the 4x8 sheet to now be the "squaring" component. I intend to add 9 or 12 inch beveled 2x4 chucks up the two edges where the 4x8 ply sheets meet at about 2 or 3 ft. intervals. That will hold the edges together.

The bottom 8 ft is made of 3/8 in plywood faces while the top 8 ft will be faced with 1/8 luan. At this point, four guys can easily tilt the assembled units into their upright position. I had to make the bases substantial because we will be performing on an outdoor stage not protected from wind and no access to tie into from above.

Thanks for all the suggestions! If you have any other ideas, please share!

 

[venuetech]

because we will be performing on an outdoor stage not protected from wind and no access to tie into from above.

Consider adding tie down points so they can be secured over night and or quickly in case the wind comes up. rehearse tie down procedures well.

 

[jcfalc01]

Great idea on the tie downs. Thanks!

 

[jcfalc01]

Here are some of the pics of our assembled units. I'm really happy with them. We've had them up and down about 3 or 4 times and the tolerances are staying consistent. Thanks for all the suggestions!