John Marshall wrote:
>
> What do you define as " really good high speed" ?

My definition of "really good high speed" is my CNC
X/Y axis drivers, old (cheap) motors 5.1v 1A (which you
can get anywhere) currently doing 10 RPS, throwing a
2kg payload, with a toothed belt and 56mm diam pulley.
Accelerates to 10 RPS in half a revolution, travel
speed is 56mm x 10 = 560mm/sec = 22 IPS with a 2kg
load. It will do much higher top speeds than that, but
the G-forces currently throw the whole machine across
the table on accel and decel, which is the limiting
factor. Very nice for a $5 motor and driver built from
junk. :o)

> I am about to do an
> update to a scanner design that currently operates at 4 ips @ 200 lpi.
> Right now my limiting factor in speed is the stepper. It's a little 6
> wire tin can job, with at 25:1 gear head. (Yes, it really does scan at 4
> ips, and that's 12" wide, 24bit color. This is not a 59.95 scanner)

A tin-can motor will normally do about 10 RPS +
depending on it's voltage/current ratio and what
voltage you use in your CC circuit. Can you give
more details about the motor spec? These 7.5' motors
are a bit fussy regarding their primary mechanical
resonance.
-Roman

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