curved stair twist

[ironman186]

Hello all

 

I am working on a set of curved railings leading up to a church pulpit .The rails are leading up on either side of the pulpit and mirror each other .

The rails are about seven feet long each ,they sweep down in a semi s curve and wrap around a wooden column 

I have the rail cap bent ,but am having trouble with getting the proper twist in the rail to keep it level

with the floor .I need to keep the upper section straight but also ,need to add a twist .

Im thinking of setting it on a flat plate ,after marking the height of each twist to check for flatness.

Do any of you have experience in this area . Thanks 

ps .  a hard thing to describe 

[macbruce]

Any chance of you taking a pic? I've tried but I can't get my mind wraped around your discription well enough to voice an opinion.

[billyO]

Is it possible to make a full sized jig, starting with something like thick aluminum wire (large enough to minimize further steps but small enough to handle the trip back to the shop as well as easy to handle) on-site to make the curve, then bring that to the shop and use as is or beef it up?

[clinton]

It is difficult to keep the top cap flat and true when bending on edge (The hard way) I have had this problem also. Some bending wrenches can help tweak it back. Make two "wrenches" that fit snug on the rail cap and twist them in opposite directions to tweak it flat again.

[clinton]

oops double post my bad

[macbruce]

Is it possible to make a full sized jig, starting with something like thick aluminum wire (large enough to minimize further steps but small enough to handle the trip back to the shop as well as easy to handle) on-site to make the curve, then bring that to the shop and use as is or beef it up?

I have in the past used thin material like 1'' x 1/8'' to bend and twist in the field  until it fits resting on the steps. Then take it back to the shop and use it for a template.

[ironman186]

Thanks for the feed back , Macbruce ,I havent figured the photo up load yet .I think I can give you a better idea .

After looking into spiral stairs a little .It is a compound curve so bent and twisted .

My question is it possible to check against a fat surface ,by marking the approx amount of twist at given locations .

since it also needs to be a straight line if looked at from afar . No so good at descriptions ,but I think you might have 

a better idea . Thanks I 'll check in later 

[Dillon Sculpture]

I have used a small bullet level, it should be level when you have it perpendicular to the length of the cap. I also use bending bars and a vise in the field to address the twist, over bending the radius as it will come out when you twist. The hard one to figure is when your whole inside corner is high, this means you need to curve the whole section down and vice versa when your outside corner is high. It is helpful to go slow and check often. You may find something of interest in my Smith Rail post.

[ironman186]

Thanks Danger 

 

I enjoyed the Smith post .Amazing work , I hope to be at your level someday.

The twisting slow will help ,and one of the pictures got my mind thinking .

One of the problems is the rail is about 200 ft from the truck and vise , but there is a trap door to a crawl space 

Instant vise mounting area , we'll see .Lots less walking ,I"ll keep you all posted .Thanks