Replies

1. 
   rob_ss | Jul 23, 2022 05:18am | #1

   A diagram would help. I'm not sure what you mean. I'm envisaging a stair rail...
   Unless you have many to do though, I would think that you would be safer and much quicker forming a concavity with hand tools and sandpaper.
   For a one off job it would take maybe 5-10 minutes to remove as much material with a rasp as a spindle molder could take off.

1. 
   thomasgerald | Jul 23, 2022 07:54am | #3

   Hi Rob_SS, I've attached a fusion render of what I'm trying to do. The maple is the curved rail, that will be attached to a turned walnut leg via dowel, but I need to scribe the end of the rail to a concave shape. (The same radius as the leg.)

   
1. 
   rob_ss | Jul 24, 2022 03:35am | #8

   There are several viable solutions already proposed now.
   None are easy but if you can find a core box bit with the appropriate diameter, that would be easiest. Many fine passes and a hold it upright jig is essential!
   They are certainly available on Amazon, though a 1 1/2" bit for $15.95 suggests the need for some safety shielding in case it falls apart!

   It is very hard indeed to cut that profile by hand, but it can be done. I'd use an 18mm diameter round rasp and finish with sandpaper wrapped round a slightly undersized dowel as you need to allow for the thickness of the paper and grit.
   Alternatively you could take it close with a less scary router bit and finish by hand.

2. 
   _mj_ | Jul 23, 2022 07:34am | #2

   Sounds like miter gauge and backup block... like you would for a cope & stick door. Without knowing more about the severity of your bend that's all I can say. Make sure the back of the cut is perfectly supported, blowout on a B-lam is misery. Rob_SS' advice is solid.

3. 
   jim_hall | Jul 23, 2022 12:25pm | #4

   If the rail is not too big, you might be able to bulk out or put a sleeve around the end of the rail so that you can stabilize and safely drill it out on the drill press with a forstner bit the same diameter as the leg.

4. 
   john_c2 | Jul 23, 2022 12:44pm | #5

   Would you be willing to make a flat on the walnut part, and attach flat to flat?

   If I only had a couple of these to do, I would use an incannel gouge. You only need the tightest fit at the ends.

1. 
   thomasgerald | Jul 23, 2022 03:39pm | #6

   That's a good idea, while watching some youtube I found this person doing exactly what I needed, can't quite see his jig though... (https://www.youtube.com/watch?v=KTeyzY18lQc&ab_channel=SeanEvelegh) around 30 seconds in.

5. 
   gulfstar | Jul 23, 2022 03:54pm | #7

   A round nose bit on the router table with clamped guides to maintain the part at a steady angle should do it.

   
6. 
   mattk41 | Jul 24, 2022 10:49pm | #9

   I haven't done a curved or radius profile but I have cut a birds mouth on the end of bent tapered laminations...photo attached. To notch with a table saw, I made a cradle out of fiber board...I think the do a profile with a router bit or shaper, you would do the same. Make a custom cradle to safely and repeatably hold and position the stock/component as is passes the cuter.