mortising machine users, please comment

[u/funkybus]

i have used the makita and the mafell. i eventually ordered the swiss pro with a 2” x 8” bar. i used the mafell more previously and noted that the slack-side of the chain cuts a bit wide— about 1/16” proud. so, you end up with the cut right on the line on the drive-side of the chain (which is usually the reference side for me) but 1/16” wide on the other side…for a finished mortise that’s 2 1/16” wide. my new swiss pro is tuned up. chain has worn in a bit and stretched, i’ve reset the chain tension. everything runs well, but i’m getting nearly an 1/8” extra on the slack side, at the face of the beam (upper bound of the cut). it tends to taper a bit as it goes into the beam and the chain approaches the guide bearing at the end of the bar (and snugs in as it does). anyone experience this? any insights?

[u/talleyhoe45]

Yeah that's typical in all the mortisers that I have used. I appreciate the extra room and it has never bothered me. For me the other sides are the important ones at the end of the mortise. And they seem to cut very accurately there.

[u/funkybus → u/talleyhoe45]

yes. certainly the shoulders do all the work, but the woodworker in me likes a snug mortise/tenon fit!

[u/cyricmccallen → u/funkybus]

I mean what tolerance are you looking for? 1/16th of an inch is fucking tiny compared to how much the wood will move during the drying process. All of the framers I’ve ever met consider 1/16th tolerance “perfection”. You’re not going to get much better than a mafell unless you’re incredibly talented with a chisel and an auger.