Re: RPM Meter

hansw wrote:

<snips>

Hello, I just joined the list.

My name is Par Willen out of Stockholm Sweden. Bought my own first lathe
just a couple of weeks ago, a SB 9 x 24 "clone" that I've spent a few
days in overhauling.

I am waiting the parts delivery for a DRO setup using the HEDS encoders
and software as per Tom Kulagas setup. While I am at it, the next thing
was obviously to build some sort of r.p.m meter to get the correct
cutting speed. I know next to nothing about electronics and thought this
list would be way over my head but lo'n behold, the first digest I read
has Hans' RPM meter in it. Jackpot! Seems like the absolute ideal
project to get my feet wet with the PIC chip.

> Is there that much of a need for a precise low RPM measuring device ?

I'm looking at fairly low spindle speeds. I don't have my trusty
spreadsheet on this PC but if we're talking cutting speeds of 70 f.p.s.
on a 5 inch diameter piece, the backgear is definitely going to come
into use with spindle speeds down in the 50-60 r.p.m. range.

On the high side would be a cutting speed of 300 f.p.s on a 1 (one) inch
piece which comes out at an absolute max of say 1300 r.p.ms at the
spindle.

Please keep it up, I'm following this one with great interest and need
all the help I can get.

Regards
PiPPi