Re: Sherline CNC stepper motors getting "stuck"

As a first test, set start speed to 500, acceleration to 500, max
speed to 1000 and see if it works flawlessly. Then increase gradually
and see where it fails.

Question#2: When using 6 wire motors with a bipolar drive (I beleive
the Xylotex is bipolar, please check to make sure) use half of each
winding for max speed. Half winding gives approx four times the speed
of full winding.

I have first hand experience of this. I quadrupled my speed by using
half windings with six wire motors.

Daya.

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "builder4wd
<builder4wd@y...>" <builder4wd@y...> wrote:

> Hi everyone,
>
> I've been working on my Sherline CNC machine with Xylotex driver
> board (set to 1/8th step) and 24 V power supply. My motors are 6-
> wire, 2 amp/phase. I have two questions:
>
> Problem #1
>
> When I try to machine a test part, I get problems with the motors
> getting "stuck"... I think desynchronized with the signals coming
> from the driver board. The motor will accelerate, get

desynchronized

> and stop moving, then start moving again during the deceleration
> phase at the end of the move.
>
> The machining is done at only 300 mm/m or about 12 inch/minute. I

get

> this problem even when I just have the mill move in air (with no
> material being cut). At first, I thought that my motors were set to
> go too fast, but I can set my motors to jog at 25 ipm, yet I still
> get the problem when I run the G-code. Any ideas on what is the
> cause/remedy?
>
>
> Question #2
>
> Since I have 6 wire motors, I set my Xylotex board to output 1/2

the

> rated current, but my motors get stuck at even the 8000 Hz step

rate.

> To fix this, I tried reducing the current from the drive to less...

I

> found that at about 0.73 amps, I can increase my step rate to 18000
> Hz when I jog the motors. My question is, if I reduce the current
> output on the driver, what do I gain/lose? What are the tradeoffs?
>
>
> I would really appreciate any help on this. Thanks.