(possibly stupid) stepper question

[anthony]

I have two "SanyoD" H-model 400oz-in steppers that i plan to use on my plasma table. i'd like to drive them directly, with no mechanical gearing/reduction.

question: tech sheet supplied with my motors gives the torque v. speed curve. its pretty straight, sloping from 400ozin to half that at its top speed.

however, the graph STARTS at 150rpm. without a reduction, i'm running about half that (1/2" pitch belts on 14T pulleys), about 70 rpm during cutting... no data is listed for 70rpm.

i thought i could step a stepper 1 step per year (say that 3 times fast) if i wanted to. the graph seems to imply thats a bad idea. am i misreading? are there problems running this slow? shouldn't i get the most torque this way, running slowly?

thanks,
-anthony

[CJL5585]

The graph just starts at 150 RPM. The torque should be a straight line from 0 (1 Step per year) to 150 RPM.

At lower speeds you should have full torque.

Hope this helps.
Jerry