Re: [CAD_CAM_EDM_DRO] Re: servo vs stepper

Stephen Wille Padnos wrote:

>Oh yeah - one other thing to check with a scope - how much jitter is
>there in the pulse spacing?
>
>You're using a hardware pulse generator, so I would expect no more than
>100 nS or so (assuming a 10MHz clock, which seems pretty popular). If
>the spacing between falling edges varies too much, that would be a
>problem. (it's like accelerating and decelerating rapidly).
>
>

Yes, I've been urging Keith to do a "headphone test", where you hook the
step pulse source to a set of walkman headphones with a series resistor
to limit current. If the step pulse spacing is irregular, it sounds
like buzzing
bees. If the pulses are very regular, it sounds like a slide whistle.
This is how I check settings for my universal stepper controller. If the
tuning parameers are not right, the buzzing bees can be obtained. When
I get the clean whistle, I know that is the magic combination of numbers.

Jon