Re: Re: Response - The Saga

Art-...how many pulses/second are actually required for most people.
A VXD is not very hard to write for up to 8192 pulses per second, but
get more difficult at 40000 or so.

Art,

If you asked this a year ago I'd have said 8192 is PLENTY. And still
is, for many people. But, these microstepping drives and step/servos
and other such are pushing the envelope. Certainly 40k would be
plenty.(written before the rest was composed!)

You mention 8k is easy, then 40k hard. What about 20k? What I'm
getting at is feature-itis. If I could have reliable step output from
windows at 8k next week, I'd be a lot more interested than if I could
have 40K someday! Actually, I'd be "chomping at the bit", either way.
But you get the point.

With a .2 leadscrew(typical) and Geckodrives/10 (2000SPR),you need
25k/second for 150 IPM. This is direct drive. Since many will use a
1:2 drive, we're up to 50k/sec. Drop back to a "quad" driver (divide
by 4 microsteps) and you need 20K/sec. for 150 IPM with 1:2 drive.

The sherline guys have 8k steps per inch (stock setup) but don't
really expect to go more than(I hope) 60 IPM. So they need 8k/sec.
with a FULLSTEP drive. Since many are 1/2 stepping, we're at 16K/sec.

The router guys(like you) usually have less SPI, but want more speed.
On the order of 300 IPM rapids, at least. A safe value to work with
here is 2000SPI. (Insert driver needs here!) Again, these microsteps
are REALLY EATIN' the pulses! Gecko's pulse-averaging drive may be
the answer to getting the speeds up/ while keeping the output stream
reasonable.

I hope you get lots of response to your question. I'd be happy with
8k/sec. and ecstatic at 28k/sec.(If I didn't have to wait too long)

Hope this helps.

Ballendo

P.S. Why 8192? (ok off list)