Setting mortise bit and chisel?

[Allen Bookout]

I have seen the methods for setting a mortise bit and chisel but do not know what part of the bit to rest on the workpiece when getting ready to move the chisel up to it's correct position. Depending on whether you set the bit on the tip of the point or the flat cutting part would make as much as 3/16 of an inch difference.

Do you measure from the tip, the vertical cutting edge or the horizontal cutting part of the bit?

[Jim DeLaney]

My method (works very well!) is to install the chisel, with a nickel's thickness between the machine and the flange on the chisel. Then, I push the bit up into the chisel until it's snug against the chisel, and tighten the bit in the chuck.

Finally, I loosen the chisel and push it up the rest of the way into the machine.

This provides enough clearance between bit an chisel for good chip clearance, and prevents clogging of the chissel and/or burning of the bit.

[Rick Cabot]

Allen,
I found the "forty cent method" for setup to be helpful and something I could remember. Try the link http://home.comcast.net/~charliebcz/...tingTrick.html .
Hope this is helpful.
Regards Rick Cabot

[Allen Bookout]

Thanks Jim!

That is the way that I did it to start out and seemed to work well but I was testing in soft wood and did not want to destroy a set just because it was not set correctly. My thought was that as I sharpen the chisels that the chisel and bit relationship will change but I suppose that the change will be small enought that it will not matter.

Rick,

The forty cent method is what I had in mind when I posed the question. It appeas that you rest the tip of the bit on the quarter and that would change the setting compared to if you were to offset the quarter to the edge and referenced it to the one of the cutting edges of the bit. It is also not the same as if I use the method above as the point sticks down a little more. This could change the setting as much as 3/16 of an inch and that seems like quite a bit of difference. This may be as clear as mud but is the best that I can do.

Allen

[Daniel Rabinovitz]

Allen
Insert a 1/16" or so kitchen counter sample, from one of the big box stores, between the chisel and frame. Tighten the chisel.
Bit is resting on a piece of wood.
Push up on the "bit" with a piece of wood and seat it into the chisel - It's sharp! ouch! My finger just hurts thinking about it.
Tighten the bit in the chuck
Loosen the chisel and push it up to seat it. Tighten chisel.
Ouch - the points hurt too.
Now you have about 1/16" clearance between the rotating bit and the chisel angle.
Worked well for me.

Addendum
Am I dumb
The 40 cent method (which I should have read first) is the same one, us old folks don't have money to throw around. Just chip samples, from power walking in the big box stores.