I've got the itch to put together a mortiser (woodwork machine),
and have some ideas about pulleys that will make a useful
one from (mainly) wood, not needing a strong column
for alignment.

The problem is, all mortise chisels use a 0.625" round
barrel, and they have to be clamped (not possible in
wood, this is a metal part), so as not to shift or rotate
in operation. The easy way is to make a sloppy bore
in cast iron, and tighten a couple of setscrews.

I don't particularly like that, though: the barrel gets
marred, and small adjustments become difficult.

So, how else can I clamp the chisel? Is it possible to just
buy something like an oarlock socket, with a tightening
mechanism? Maybe use a pair of V blocks with a hinge and
tightening screw? Or, one hemicylinder socket and a V block
opposing it?

On 11/13/2011 1:31 PM, whit3rd wrote:
....

The problem is, all mortise chisels use a 0.625" round
barrel, and they have to be clamped (not possible in
wood, this is a metal part), ...
....
So, how else can I clamp the chisel?...

The typical way in such w/ wood is to drill the hole in the block, put a
kerf on one side for some clearance and then use one or more bolts,
tee-nuts or simply thread hardwood itself and tighten away...

--

On Nov 13, 12:31*pm, whit3rd wrote:
I've got the itch to put together a mortiser (woodwork machine),
and have some ideas about pulleys that will make a useful
one from (mainly) wood, not needing a strong column
for alignment.

The problem is, all mortise chisels use a 0.625" round
barrel, and they have to be clamped (not possible in
wood, this is a metal part), so as not to shift or rotate
in operation. *The easy way is to make a sloppy bore
in cast iron, and tighten a couple of setscrews.

I don't particularly like that, though: the barrel gets
marred, and small adjustments become difficult.

So, how else can I clamp the chisel? *Is it possible to just
buy something like an oarlock socket, *with a tightening
mechanism? * Maybe use a pair of V blocks with a hinge and
tightening screw? * Or, one hemicylinder socket and a V block
opposing it?

If you just gotta make your own, you could get a cheapie chink
mortising set for a drill press and adapt the holder. Or just attach
it to your own drill press and be happy. The key is in tuning up,
sharpening and polishing the mortising bits, not so much the driving
unit or the work holder.

Stan