Help making Jacks for Hollywood flats

[AgentSlade]

Hello I have 5 4'x8' Hollywood Flats that I need to make Jacks for but I'm not sure how high I need to make them and how far out then need to extend behind the flat. They have no corner bracing and have a toggle in the center.

I have a bunch of left over 1x3 boards.

I'd prefer to have them extend less if possible. These are for a booth at a convention. My plan is to clamp them together and sandbag them.

I'd appreciate any advice.

 

[AgentSlade]

This is my layout

 

[JonCarter]

Are the 5 flats to be placed in line making a 20' straight wall? Or are they to be angled some way? (E.g., "Z" pattern of some kind?) If the former you will need jacks with longer base horizontals and more sandbags on them to ensure the wall won't fall over. If the "Z" pattern layout I suggest the jacks be 8' high with 2' bottom horizontals, hinged to the "left" side of 4 of the flats and hinged to the "right" side of one of them. (When assembled there will be jacks at each joint and at both ends of the assembly.) (If attached to the flats you''ll have only 5 pieces to load in & set up.) If the design calls for a 20' straight wall, make the bottom horizontal of the jacks 3' or 4' and use more sandbags on them.

 

[darinlwebb]

What you've drawn is a broadway flat, not a hollywood flat.

Typically I'd make jacks out of 1x3 (1x4 if that's what I've got around), and it's a triangle about half the height of the flat, and with the rail about 1/3 the length of the vertical stile. The Stock Scenery Construction Handbook suggests a stile the same height as the flat, with the rail about 1/4 the length. It suggests a diagonal brace going 1/2 to 2/3 up the height of the vertical stile.