bobgaggle
Well-Known Member
So this isn't really scenery, but my woodworker father in law is building a hidden door bookcase and is running into some trouble. I figured maybe some theater people would have a fresh perspective...
The case is 46"w x 81"h x 10"d. It hinges on Rixon pivot type hinges at the top and bottom, http://www.rixson.com/pivottypes/, and swings into the room (or i guess downstage if this was in a theater haha) The issue he's having is that the case (which is 3/4" ply construction with a 1/2" ply back) is warping under its own weight and isn't sitting flush with the wall when its closed. The top corner is leaning into the room while the bottom is flush with the wall. He was contemplating added a 3/4" ply sheet to the back to stiffen the whole thing, but I feel like he'd still have the same problem.
My solution is to weld up a 1x1 16ga. steel tube frame that will get screwed onto the back. I'm not an engineer but I feel like it'll be stiffer and weigh less than a 3/4" sheet. I figure standard steel flat construction with three toggles. I may be getting too clever for my own good, but my thought was that as I weld it flat on a table, I'll shim up one corner an inch or two and leave the rest on the same plane, building it intentionally warped in the opposite direction that the case is. When the frame gets screwed to the back of the case, it'll twist and provide some spring tension to pull that corner of the case back. Some moulding acts as a stop to keep the door from overswinging and to conceal the seam.
Any other ideas? He's already tried an aircraft cable and turn buckle across the back (like on a screen door) but it didn't help at all. Is another sheet of ply the way to go?
The case is 46"w x 81"h x 10"d. It hinges on Rixon pivot type hinges at the top and bottom, http://www.rixson.com/pivottypes/, and swings into the room (or i guess downstage if this was in a theater haha) The issue he's having is that the case (which is 3/4" ply construction with a 1/2" ply back) is warping under its own weight and isn't sitting flush with the wall when its closed. The top corner is leaning into the room while the bottom is flush with the wall. He was contemplating added a 3/4" ply sheet to the back to stiffen the whole thing, but I feel like he'd still have the same problem.
My solution is to weld up a 1x1 16ga. steel tube frame that will get screwed onto the back. I'm not an engineer but I feel like it'll be stiffer and weigh less than a 3/4" sheet. I figure standard steel flat construction with three toggles. I may be getting too clever for my own good, but my thought was that as I weld it flat on a table, I'll shim up one corner an inch or two and leave the rest on the same plane, building it intentionally warped in the opposite direction that the case is. When the frame gets screwed to the back of the case, it'll twist and provide some spring tension to pull that corner of the case back. Some moulding acts as a stop to keep the door from overswinging and to conceal the seam.
Any other ideas? He's already tried an aircraft cable and turn buckle across the back (like on a screen door) but it didn't help at all. Is another sheet of ply the way to go?