pockets/dados

[john_hartman]

I'm running a new PRS Alpha with 2.2 HSD and air drill. The following issue is something that I have been "living with" on my old machine but would like to try get it resolved.

Two issues-

1) When cutting dados I get a ridge along the center-bottom of the dado. Its about 3/32 tall and about 1/16 thick (See attached photo.) This is the case when using .5" ply and using a .25" compression bit. I would simply like the bit to make more than two passes. Apparently the "pocket settings" with step-over values has no affect on this. It is controlled by the "dado" settings which just allows you to choose climb or conventional. Plywood is generally around .47 to .48; I have a fit clearance of .015. The math with a .25 should overlap enough to avoid this bit it doesn't. What am I missing? Is there anyway to get multiple passes when cutting dado's?

2) On tenons I get a wavy edge. (See attached photo.) This only occurs where assembly marks are located. If you look closely you can see where the cooresponding holes has a bump right behind it. I'm thinking the when the bit encounters the holes where there is less resistance the bit deflects somehow..? Again this is using a .25" compression bit. Any ideas on a remedy? My thought was to have the holes drilled at the end, but I don't believe that is possible.

[davebryant]

John,
With the tenon issue set a cleanup allowance amount in the pocket settings, maybe 5 or 10 thou. Worked for me.

[garyc]

John...
In short, both issues look to me to be physical. Either bit or machine deflection is the most likely cause.

The dado geometry, even tho they will pocket, math says that they dont need to, so one will not happen. Compare the width of the dado that has been cut (my guess is oversize) to what is shown on the eCabs nested sheet.

Give me a call at work and I can take you thru a few steps, this should not be hard to fix.