Re: [CAD_CAM_EDM_DRO] Re: Does control s/w affect machine performance? max step rate

turbulatordude wrote:

I showed off a very hasty 2-axis retrofit of the 150 Lb minimill at

>the
>
>
>>last NAMES show. I have some very old size 34 stepper motors
>>
>>
>connected
>
>
>>to the original leadscrews with a 1:1 belt drive. I was demoing it
>>
>>
>running
>
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>>at 90 IPM, which works out to 1440 RPM. That did take 48,000
>>
>>
>steps/sec
>
>
>>on the G201 (10x microstepping).
>>
>>Jon
>>
>>
>
>
>OK, does that show up as 32,000 steps per inch ?
>

Yes, that sounds right.

>
>Seems that the thread pitch is small and that a faster pitch would
>offer about the same delivered power ?
>

But I just used what was in the machine as it came. Since the show, I
discovered the Y axis bracket had sleeve bearings and no thrust bearing to
speak of, so I carved it up to insert some small ball bearings into it.
Otherwise,
what I have done so far is basically a bolt-on retrofit.

>
>halving the pitch and going 1:2 would offer the same speed. halving
>the pitch with 1:1 would run the motor lower on the curve and offer
>the same power ?
>
>It seem that if you have 32,000 steps per inch, you are way past the
>resoulution one would expect for a leadscrew. 10,000 steps per inch
>would offer a theroetical 0.0001" placement.
>
>I'm not saying that super fast pulses don't have their place, but is
>there a real need for them ?
>
>

Probably not in the mini-mill. Anyway, 1/10th microstepping makes the motor
have 2000 "steps", but I'm pretty sure that it will not respond in any
precise
manner to moves at that resolution. On the other hand, it moves almost
silently,
just the slightest rising and falling tone.

Jon