[How do I?] Mill The Round Slot For My Replacement Cross-feed Slide?

[Rex Walters]

That works great if you have a cutter that has a shank smaller than the smaller slot size is.

Yup. The t-slot cutter I have has a (hardened) shaft too large to fit. Since I don't mind sacrificing a cutter to this particular cause, I plan to simply grind a flat the entire length of one side such that I can fit it through the upper slot (basically extend the existing flat for an end-mill holder).

 

[Rex Walters]

Sorry. Just realized that might be puzzling since, of course, the tool still has to rotate. Here's a photo of my existing cutter:



The "neck" on the left is small enough to fit through the upper slot, but the silver part of the shaft isn't (as 4gsr points out). So I plan to grind a flat lengthwise on the silver part of the shaft until I can fit it through the upper slot. If necessary, I'll grind flats on two side vs. just extending the existing flat, but I think I can get it to fit with just one flat.

 

[ogberi]

I had to do a similar job for a friend, and ended up using a small enough cutter so the shank would fit through the top of the slot, then cut one side of the slot at a time. Took longer, but worked. I lucked out that I had a smaller cutter (looked to be home-made) that worked for it. I was worried that it would bind up, but all went well.