A way to repair a taper seats?

[Wiseco]

Hi,

We have a birmingham knee mill (similar to bridgeport knee mill) and it seem that our spindle taper seat is damage. We think the last owner of that machine may have damaged it with dirty collet (chips on it). Is there a way to repair or regrind the taper seat without removing the spindle itself?

Maybe the best way would be to tilt the head at the angle so a side of the taper seat is horizontal and mount a grinder on the table and regrind it.

Give me your 2 cents one that problem.

Thanx!

[widgitmaster]

I reccomend not grinding or cutting it in the machine!

If the spindle was damaged from chips, then it was not properly heat treated and is manufacture defective! Try to locate a replacement spindle, or replace the entire head assembly!

I have run Bridgeport mills that were very old and badly abused, but the spindle nose was always in perfect condition!

Eric

[Wiseco]

Finally, we took, with bare hand, a honning stone and let it touch the taper seat while the spindle were turning. After that, the surface was clean and without little bumps. I think it was chips that were stuck in the spindle.

Now our facemill make a clean job.

[NC Cams]

It is NOT uncommon to assemble the spindle, and then grind the ID concentric to the axis established by the bearings/spindle as an assebly - that's how Bridgeport AND Hardinge made them perfectly true at the time of manufacture.

If you know how to do it and protect against grit/debris going all over and/or into the spindle bearings, you'll have no problems what-so-ever.

EXPERT spindle repair shops do it that way as well.

[gus]

sounds like they did what they needed to. if not careful , this is what happens in any machine