FMT Users

[Don L Johnson]

I've noticed that when I am plunging the bit in for a mortise, the bit sometimes grabs the side of the mortise, resulting in taking a cylindrical bite out of the entire mortise wall resulting in a mortise wall that has slight divots in it. Althought this flaw is covered up by the sholder on the Tenon, it seems to create more wear and tear than necessary.

The FMT table is locked into position, so no movement there, and the router is a new Triton, so no abnormal movement there. Does everyone else experience the same situation, or am I doing something wrong? Thanks,

[glenn bradley]

I don't have the FMT but did experience the problem on my shop made jig. I solve it by plunging out the center of the mortise first and then running the already plunged bit around the outside instead of plunging at the outer edge.

[John Lucas]

Don, are you using a straight bit or spiral cutting bit and if spiral, is it up or down. I use upcut spiral and do not have that problem. I plunge all the way at one end and then move to other end and plunge all the way...then I use shallower cut and cut in between...in a series of depth cuts. If you were using a down cut spiral with this method, you would have problems. If you were using a straight bit, you would have problems...it needds shallaw cuts and then plowing from end to end at each depth. I am leaving out the wood variable -- some can be real tough to have smooth cuts.
I will add one thing. I am not certain how you have your workpiece mounted on the table, but if there is any room for vibration of the piece, that can cause problems real fast.
Whoops, I was initially responding with thought that you were using the MFT (Festool) table. Now I assume you were referring to the Leigh FMT...dislexia on my part, but similar answers apply.

[Don L Johnson]

John,

I use upcut spirals as well. What I don't do is graduate the depth of cut; I do a full plunge depth on the first, then move over a bit and do another full plunge depth. I'll try the partial depth for each series. I'm using a 3/8" bit...about how deep do you go at a time? Thanks,

[John Lucas]

Same as you...full depth. Except my second cut is full depth at the other end. then back and forth gradually in between

[Randy Ferguson]

If you start the mortise with the bit all the way to the right and move the router to the left you will get a much cleaner slot. I think that if you try this it might help.

Isn't the FMT the shiz?

Cheers
Randy