Thread: Tailstock Taper Clean-up

Hi John,
Do they suggest holding the reamer in the lathe spindle?

Have you tested any other tapers in the tailstock?
MTs have to be really really clean if you want to spot them.

Stuart

Originally Posted by electrosteam

I have just completed my first test MT3 taper work piece at TAFE, destined to become a die holder or similar for the tailstock in my lathe.

The piece was cut with the topslide angled, then cylindrically ground.
It shows 80% contact over the middle when tested against a test taper with bearing blue, and is rated as good by the class instructor .

The piece shows, however, excessive contact in the middle when tested in my tailstock.
The finger test detects some dirt and small rough spots that could account for the tight fit.

Various sources suggest that 'cleaning' the tailstock with a MT3 taper reamer is the classical solution.
Can anyone please recount their experiences in doing this.

I will level the lathe and test turn between centres to ensure the tailstock is correctly aligned, but what other precautions might be advisable ?
What lubricants and speed are recommended ?
How much force ?

Happy machining,
John.

I think that it depends on the condition of the reamer. Any one high or dull tooth will alter the path from the ideal. The reamer is supposed to be self-registering in the taper, but I think there's enough wobble room to possibly, maybe introduce error. Having said that, I mounted my reamer in the chuck since it has a cylindrical shaft and took a couple of light passes turning by hand. I was able to remove some burrs and bad contact with just a few turns.

I think you could almost take a very light pass and inspect the result visually to see if you are cutting heavily in one sector of the taper or not.

Greg

Stuart and Greg,
As always, great advice.

The test at the college was with a very good sleeve, and the piece was just off the grinder.

I will blue a new hard centre in the tailstock before making any decisions.
The tailstock has the standard end-tab anti-rotation recess and my Jacobs chucks have the matching tabs, so slipping has never been an issue.

The light touch and turn by hand is noted, and will be followed.

John.

John, here's a more complete discussion, and some pointers that I had forgotten:

reaming tailstock taper advise - Practical Machinist - Largest Manufacturing Technology Forum on the Web