Silly machinist... Was: Accuracy and heat was Re: re: Re: New file upld to CCED

> machining....they machine the part to the "right" size while
> it's hot, and then wonder why the #$@#$ thing doesn't fit
> right later on! :)

Yeah, but if you're really dedicated to looking like a novice you could make
the part three times in a row and not realise it was the massive heat build
up causing the problem.

Not that I've done that of course... But have you ever tried to force a
20mm OD bearing into a hole with an "interference" fit of .3mm? Strangely
it doesn't work.

I was using a friends CNC'd "lux-cut" mill to make the holes and taking some
huge cuts as I'm used to my current (very) light weight lathe and the
novelty of pushing an end mill hard was too tempting to pass up. The part
had very little mass and was getting seriously hot before the finishing
cuts.

After some sagely advice from the owner I turned on the coolant pump and it
all became brightness and light :-).

Cheers, Chris.

* Design engineer, Assembly worker, Cleaner.
* And very amateur machinist.
* Ohmark Electronics. PO Box 5302, Christchurch, New Zealand.