Thread: Bench top chisel morticers worth it?

Your mileage may vary, but holding things by hand in a mortiser is exceptionally difficult, which is why all have clamps/holddowns. I used to think the same about X-y tables but after using mine I don't see why you wouldn't want one. The biggest issue with any mortiser is the chisel binding with the sidewalls of mortise due to heat/expansion etc. Benchtop units typically have small (but adquate) vices to overcome the friction created, but every now and then you'll find it'll be solidly jammed. Floor units have the mass to allow you to put all your force into unjamming it without lifting the whole unit off the bench/flexing the leaver.

To minimise the liklihood of jamming, the way mortisers work (particular benchtop units) is you take small plunges across the width of your mortise, leaving small gaps between each plunge, you then go back removing the small gaps. Repeat step 1 & 2 until desired depth of mortise. In principle having the x-y table allows you to lock in your work piece and you set left and right stops so it becomes more or less a no brainer process. In practise this isnt as easy due to binding resulting in you pulling the work piece out forcing you to reset your stops. So what i do, is use the mortiser to get close to my desired mortise boundary and depending on project i'd either manually plunge on the line or adjust my tenons accordingly. The x-y, makes the back and fourth movements significantly easier as well as setting the fence.

Yes I did mean the one the motor goes up and down on. There are two more to the bed though so I should have made that more clear.

tonzeyd post covers the jamming they do. They jam good and hard . Two sets of hands wouldn't get it off without it being well clamped. I sometimes have folded sand paper behind the wood clamped in because the wood slips out from the clamp . One of My apprentices broke my cast table tightening it to hard rather than put in the sand paper . That was one of my repairs .
A better practice is to prepare the chisels correctly by removing steel from the chisel behind the leading edge . With a linisher sander I take a few passes down each side. So when plunging the leading right sized edge is the part that rubs hard and the rest not so much. Jamming can be much worse on the first plunge in so taking it in small steps is the way to go.