Re: Reamer feeds - fast(!)

"Robin S." <lasernerd@xxxxxxxxxxx> wrote in message
news:vOiWe.3264$6Z1.791973@xxxxxxxxxxxxxxxxxxxxxxxx
> Yesterday I was having a hell of a time reaming some cast D2 flange steels
> into a G2500 cast iron die shoe.
>
> I found out (after asking) that I was feeding much too slowly and the hole
> was too small for the dowel, complete with the 6-8 lines of contact down
the
> hole.
>
> The correct specs were:
>
> 16mm reamer, HSS, Guhring, 8 flutes (IIRC)
> 90 RPM
> 10+ IPM
>
> This resulted in a "tap" fit which will not allow the dowel to fall out
> (upper die shoe) but large enough to not gall the dowel which is a very
> common (and severe) problem.
>
> I've never seen a reamer fed so quickly. I've heard Cliff say it's easy to
> underfeed a reamer, I didn't think it was that extreme.
>
> Any thoughts on this subject? I'm still astounded that this technique
worked
> so well. Is this how they're run on CNC machines?

90 RPM x (.014 per rev chip load x 8 flutes = .112) = 10.08 ipm

About middle of the road as far as chip loads for reamers go.

Rough rule of thumb is half the speed, twice the feed of a drill.

..008 - .016 per tooth for a reamer that size is typical
..



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