Machining Arched Top Rails for Doors

Advice on shaper techniques for curved top rails, in order to avoid breaking the pointed tip of the sharp corners. November 23, 2012

Question
I am getting ready to build some doors and need tips. The top rail of the upper doors is curved. Normally when I do arches, I do a cathedral stile so there is a flat part at the bottom and it is less likely to chip out. The homeowner wants just an arch and no little flat part at the bottom. Does anyone have tips for doing doors like this without a chip out on the bottom right corner? My only thought is to leave it flat for about 1/2" and then start the curve.

Forum Responses
(Cabinetmaking Forum)
From contributor J:
On eyebrow arch doors, I bandsaw the arches 1/8" oversize, and climb cut the 3-4" that normally blows out first, then feed the part normally. Get about 99% with that method.



From contributor C:
If you are going to do this style of door, the fastest and safest way that I know is to have two sets of sticking cutters, one clockwise and one counterclockwise. This is the method we use for perfect and consistent cuts on the full eyebrow arch. I know this is probably not practical for you, but perhaps something to consider if you have overwhelming demand for this door style in the future. I would not advise anyone to perform climb cuts freehand, unless extremely experienced.


From contributor I:
The best way is a two spindle shaper with matching heads turning opposite directions. You cut from the left half of the way, then from the right the other half, so you finish in the center. Otherwise, a good pneumatic fixture and go slow exiting.

I have at times used the following machining sequence:


1) Cope right end
2) Rough cut arch with bandsaw
3) Machine arch with bearing and template
4) Cope left end last. The top of the rail, which is straight, will be against your coping sled/fence. By coping this end last, it will help clean up any breakage of the fragile corner.