radius sanding
Posted: Fri May 19, 2017 3:04 pm
In building a banjo I needed two 3x5" maple blocks sanded to an 11" radius.To do so, I first mounted a strap hinge 3/4" above the table to my rip fence with T-blocks and 1/4-20 bolts. With J&B Weld epoxy, I mounted a 1/4" shelf hanger bracket to the end of the hinge.
I next made a supporting frame with 1/4 hole for the bracket to engage. This frame supports the block upright to be sanded such that the center of the pivot is 5 1/2" (half the 11" diameter) from the face of the block. The block is then attached with 2-sided tape and the fence is adjusted such that the block is well supported by the edge of the table. (I don't trust the 2-sided tape that much!)
I just barely touch the face of the block to the sanding disk as to take off small increments at a time. I feed the block into the sanding disk against the motion of the disk; remove the block support and block from the hinge pin; bring it to the back; reassemble and repeat.See photo.
I next made a supporting frame with 1/4 hole for the bracket to engage. This frame supports the block upright to be sanded such that the center of the pivot is 5 1/2" (half the 11" diameter) from the face of the block. The block is then attached with 2-sided tape and the fence is adjusted such that the block is well supported by the edge of the table. (I don't trust the 2-sided tape that much!)
I just barely touch the face of the block to the sanding disk as to take off small increments at a time. I feed the block into the sanding disk against the motion of the disk; remove the block support and block from the hinge pin; bring it to the back; reassemble and repeat.See photo.