Next up was the ER32 high-dollar, high-precision SYIC Techniks 5/16" collet.
It also is much better quality, smooth bore finish, proper chamfering of bore edges, no buffing wheel cover-ups.
But, it also had numerous nano-sized metal hairs emerging from the slits. So, cleaned them out with a fine dental pick.
After fitting to the mandrel and painted. Checked its taper with the dial test gauge, almost dead-on.
Started with a light 0.0005" cut, and let the powered compound make several passes until spark-out.
There was very slight wasp-waist shape, and it was barely eccentric.
It was so close that it cleaned-up on that first cut setting. Finished it off with the craytex, oiled, and put it away.
Last was the 1/4" collet. This one blew me away.
First, it wasn't a 1/4" collet, it was a 6mm collet marked 1/4". :headscratch:
Then, after mounting, found its taper was so far off, that I had to stop and double-check my setup.
Sure enuff, its supposedly 16° taper angle worked out to 17.25°.
And worse, it was extremely eccentric (by several thou) and WOBBLY! :wantmommy:
Started the cuts, and they revealed the seriousness of the issue.
In this pic, you can see the severe out-of-taper. About 0.005" of the radius has already been ground out, long way yet to go.
Circle #1 - The sides aren't even straight.
Circle #2 - You can see the rough machining. The polisher guy apparently missed this one.
So, decided to stop here for awhile. Let the machines and me cool-off.
Submit this post, and take a nap...