Re: Stepper motors ...

[Jon Elson <elson-at-pico-systems.com>]

Robin Szemeti wrote:

>While we are talking about stepper motors .. perhaps I can give another plug 
>to these Sanyo H-Series motors I've been using recently ...
>
>I'm using the 103H8222-5141 (double stack NEMA 34) motors ... according to 
>the spec sheet they give  around 5Nm of holding torque (thats ~720 OzIn)  and 
>around 4.8Nm all the way to 1KHz (thats 300rpm)   still giving 3Nm at 
>3KHz(900rpm) .. thats with 4A/100VAC of drive. 
>
>They make your old 110 OzIn steppers look like rubber band powered motors .. 
>not just because they are 7 times as powerful at stall, but they carry that 
>torque well up into the speed range. Thats perhaps the most amazing thing 
>about them .. the wide range of speeds they will carry a good amount of 
>torque over.
>
>This is why I'm so keen to see a decent pulse rate solution for EMC, to allow 
>me to use the full potential of the available hardware.
>
Huh?  EMC can spit out step pulses at 3 KHz with no problem at all!  I can't
imagine why you think it can't.  Is it because you are using a 
microstepping drive,
and really need 30,000 pulses/second for x10 microstepping?  Ahh, then I 
have a
solution for you.  See http://jelinux.pico-systems.com/univstep.html for 
info on
my Universal Stepper Controller.  it can put out VERY smooth trains of step
pulses up to 300,000 steps/second, and can be used open-loop or with 
encoders.
it has 4 digital step rate generators which produce precisely timed 
pulse trains
with 100 nS resolution.  It also has 16 opto-isolated digital inputs, 8 
positions
for solid state relays right on the board, and emergency stop logic, too.

Jon