Reply To: Self Gauging Tapers for Shrink and Interference Fits

[Clive FosterParticipant @clivefoster55965]

NDI

I'm glad you like the idea.

Overall length isn't an issue because you always push the tapers fully home. Small errors in relative taper diameter merely alter the actual interference ached slightly. In practice it's far easier to get very close to what you intend that it is with a standard parallel fit.

To my mind the great thing is you can see exactly what's going on as you bring things to final size and adjustments are feasibly measurable.

Who can guarantee to take 1/2 or 1/4 thou off parallel shaft or hole? Even with the angled topslide trick and a lathe in first class order.

In principle the final cuts for self gauging tapers are effectively an extreme example of the angled topslide trick.

Worst point is that gauging and setting final diameter by longitudinal movement along the taper makes the relationship between cut and diameter a bit unintuitive. Which is why drawing out and calculating first is a good idea.

The angles simply fall out of the length of the fit / taper. Basically during set up the DIT movement as you traverse along the test bar needs to correspond to the fit. So if I want 1 thou of interference over a 1/2" long part I'd set-up for 8 thou over 4 inches using the taper attachment. If you are using the topslide 4 thou over 2 inches is probably practical.

Which is sensible magnitude of measurement. Even you only have a Unique indicator and an old Drummond.

Clive

 

Edited By Clive Foster on 21/07/2023 11:49:40