Giant arches

[cvanp]

Hey all,

We're starting to move from the design phase to construction phase in Guys And Dolls. We've already built our stage rake and now we're starting to build several giant arches that form the sewer in the show.

Here's an image:



I've got accurate measurements and everything for how big the arches need to be, the problem is making them - we aren't quite sure how.

I want them made out of luan, as it seems that is our most cost-effective way to do things (plus if we used something like muslin that tends to ripple when people walk by it, in my experience). The problem is figuring out how to cut the actual arch. Is there a certain way we might want to approach building this?

Thanks,

[Charc]

I have some plans I can look at for an arch, but it won't be what you want. Of particular interest for you though would be the top section, I think.

I'll take a look at that soon.

[Van]

Traditionally, thie sewer scene takes place against a silly looking backdrop. I like your "Cut-Drop" look a lot better. These could be made as Cut Drops, but I think you are looking for a hard solution. I need to run home and do some drawing I'll post a suggestion in a bit, if no one else beats me to it.

[cvanp]

Thanks Van. Any help you can provide is great! You're right about the silly looking backdrops... that is what I was making every effort to avoid. Of course, a backdrop would have been a lot easier. Now I have to figure out how to build this behemoth...

Thanks again

[SHARYNF]

Van is the master here, but sometimes taking lengths of 1 inch pvc pipe, glueing them to make the length and then bending them into the arch works fine. You can also get a material with stretch ability, or attach luan Trick is to met the side pieces to be stiff enough so that it will force the pvc to keep the bent shape.

Sharyn

[cvanp]

Sharyn,

thanks for the suggestion of PVC. It sounds like it could work but it might be a bit complex to build (and seeing as how it's all volunteers, parents, etc. we have to keep it relatively simple). Plus I'm not sure if PVC would present a budgetary problem - although that's just an unfounded concern, I don't know how much 1-inch PVC actually costs.

Thanks for the suggestion though!

[jwl868]

I’ll put in my two bits on this, but I, too, defer to Van.

Will the arches be hung from a pipe?

Why not use “conventional” flat construction methods: 1x4 frame with the lauan cover?

Based on your sketch, I took an educated guess at the dimensions (Semi circle, 12’ radius), but it looks like at least 8 sheets per arch. The construction may be complicated by how wide the panel needs to be at the side/base and how wide the panel has to be at the top (between the top of the curve of the arch and the bottom of the teaser.) [I assumed 3 feet for the bases and the top of the arch.] By complicated, I mean working within the limitations of 4’ x 8’ sheets and then how much lauan will go to waste.

I also think you’ll have to build it in at least two pieces – left and right. But even those may be unwieldy to move into position. May be difficult to flip over if built face down.

**

Perhaps you know your pool of volunteers: But you should be able to find a 3 to 4 people with power tools and the ability to use them. My own experience is that people are always willing to help and will do good work, they just need the instructions. In any case, construct the upstagemost archway first – errors/blemishes will have the best chance to be hidden and everyone will have learned a few things by the time you do the front archway.



Joe

[gafftaper]

Once again pointing out Van's the master here. But I would go with 1x3 or 1x4 standard flat construction techniques here on the sides. Build it in four sections, the two square areas and two half arches. For the arch section, build the top like a normal flat and make the bottom come across at an angle. Then throw a few extra angle pieces in to help with some extra support. You won't have 1x4 support in all places so the Luan will be a little bit flimsy in places. Something like this below.

[Van]

I'm no master. I'm just a carpenter. Actually what gaff put up is just about what you're going to see from me. I would add that although my drawing does not show a return on the inside of the arch one could be easily added. I threw this together real real quick so som other things to take into account. To reduce the weight of the piece you can rip down the internal pieces < toggles > to 1 1/2" - 2 " don't go any smaller or you're gonna get bowing. I'd probably use 1/8" Luan on this arch, again as a weight issue. Toggles could be moved to 4' centers but I wouldn't recommend it, If you were to use 4x12 sheets of luan you could easily go to 36" O.C. Take a look at these I'll chaeck back later for questions/ clarifications.

[cvanp]

Wow, Icewolf and Van, you guys are awesome!

Now my next question: what's the best way to get an accurate arch shape cut from the luan? I know how to frame it out now, but that's the best way to make the arch actually an arch? And make it look good? I guess what's tough is that it's a circle shape, and that doesn't seem too easy to do.

Thanks again!!