On 2010-08-01, Ignoramus28671 wrote:
On 2010-08-01, DoN. Nichols wrote:
On 2010-07-31, Ignoramus28671 wrote:

[ ... ]

OK thanks. I do not know if Jon's PPMC can take in analog signal, I am
unaware of whether it is true or not. But if it could, it would be
nice. I will check with him.

Have it put out more than nominal speed voltage and run the
output voltage through a pot on the way to the VFD's input. That way
you can go from your selected amount above the nominal speed down to
zero speed (or perhaps add a fixed resistor on the bottom leg of the pot
so you don't quite get down to halted).

It is not really for the VFD, it is for the rate of feed.

Oh -- you're right.

Hmm ... a spare encoder on a knob to be read by a spare axis?
Perhaps run a display somewhere near (or prominently in the system's
monitor) showing how much the speed is boosted or reduced.

The BOSS-3 Bridgeport had a feed speed pot which could only be
used to reduce the speed -- so if you were starting to build up aluminum
on your mill, you could slow the feed while letting the job finish.

It was a nice Allen-Bradley pot in a nice Allen-Bradley mount
(same hole as the switches and coolant proof). So yours did not have
that? (or all of your switches and controls went away when you sold the
controller I guess.)

Enjoy,
DoN.

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