Open stair stringers on CNC
1/31/15
I have a dilemma concerning the machining of open stair stringers on a new SCM Accord CNC router. The material being machined is Oak veneered plywood in varying thicknesses from 1 1/8" up to 2 1/4" (self support).
This material is being machined good face down on a rail and pod base. The perimeter cut out is no problem but I am having some difficulty with the mitred risers, specifically how to machine them with the best result. I am testing three different methods:1.Saw 2.v-groove router and 3. Five axis straight router bit.
The saw option creates too much of a back cut at the bottom of the rise and run creating the need to upsize the stringer height and the 5 axis straight router option doesn't appeal to me because of the length of tool needed for the tool holder to sufficiently clear the work piece.
I am currently favoring the v-groove tool but I am having problems with torn out veneer on the bottom (good face) of the part. A spoilboard lessens this tear out, but using a spoilboard on a rail and pod machine (with only one pump) in a high production environment poses some difficulties.
Any advice from similar situations would be appreciated.
Thanks