Need Help Solving/Sourcing Extra Long Taper Pin Problem

Howdy,

I've got an old American Millrite manual mill that i'm trying to recondition to offload so i can drop in a newer slightly larger mill. My issue is that the nod on the head has developed a wobble from the poor repairs of a previous owner on the two/four taper pins that fix the shaft on which the head pivots to nod. I believe he ran into the same issue i'm having now which is the difficulty in sourcing a long enough taper pin reamer to match the taper the full length of the bore. From the attached pictures you can see the pivot point is about 5" of which the shaft to be fixed to the mast casting is 3". I can find #4, #5, #6, #7 taper reamers, but i cannot for the life of me find any thing like a combination reamer (it covers the sizes from #4-#6)to cut the whole taper at once since i am doing this manually and do not trust myself to independently match 3 tapers to each other. More frustratingly, the #4 i got (thinking i could match the tapers) drops so far into the hole, i cant get any hold on it for which to apply the necessary torque or pressure for reaming/cutting.

If anyone can help me source a long taper pin reamer that at least will cover the range of taper from 0.319" to 0.252" such that i've got about 0.25" of pin extending out either side of the main shaft. Or help with some other solution to fix this shaft.

I suspect you are going to need a special reamer made. The first names that come to mind Gammons, Alvord Polk, or Lavelle & Ide.

I'm going to try and see if one of our neighbors that run a precision grinding shop will grind down a #7 reamer. A #6 looks like it might work, but definitely wont cut the taper that is there currently which extends over 5".

Have you sourced taper pins of sufficient length?

Optimist says glass is half full.

Pessimists say glass is half empty.

Engineer says the glass is wrong size.

Go to McMaster Carr, get the taper pins with hex nuts (for extraction).

Ream both sides for large diameter on outside, small diameter inside the column. One side at a time, install one side, then ream the other side.

Ignore the factory, they went out of business.

Yes. That's a stupid design.

Lots of better ways to do it. Use a straight pin. Use a set screw on a flat. Drill and tap the shaft and countersink the bracket for a flat head screw. Etc.