3 degree tapered shims

[cathead]

This morning's project was to make a pair of lathe tool shims to angle the cutter to fit my machining needs.
By using the shims, one can rotate the cutter to the left or right on any lathe tool just by sandwiching the
tool between the angled shims. It will be easy to shim for some relief where needed. It would be really
handy for making Acme threads. The machining was pretty straight forward as I angled the vise up
3 degrees and held the 1/8 inch thick material against a large block sticking out of the end of the vise for ease of cutting.

These shims are 3 inches long and 5/8 inch wide and are tapered on the face. I used a diamond
hone by hand to remove the scale and the machining marks so that part took a while. The material was
a piece of 1/8 x 3/4 flat hot roll material to start with.


I drilled holes in them so they can be kept together when not in use. If I sandwich
the cutter between them, the angle will be 3 degrees and if I shim both underneath the
lathe tool, that would give me 6 degrees. If this proves to be useful, I might make
another pair of some other angle. If I make another pair, I will use a small grinding
wheel for some of the finishing work.

A sine chart was used to verify the angle along with a little simple math.

 

[cathead]

Today was a chance to use the tapered shims to machine the relief on a carbide cutter tool.
I have no idea what carbide this might be as it is a parallelogram of 100 degrees but decided to
make a holder for it as I have several in my carbide scrap box. The carbide has straight walls
so may have to do a little custom relief work on a diamond wheel. Maybe I will try it first and
see but I have an idea that it is going to need attention. It may work if I run the carbide slightly
below center as it is. The 3 degree shims came in handy for holding the tool as I machined off the
reliefs on the tool holder.













The shims are quite handy and save time since there is no need to nod the head just to make several simple cuts.