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Author Topic: Slow spindle on my lathe  (Read 4727 times)

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Slow spindle on my lathe
« on: August 19, 2010, 08:36:37 AM »
Hi!

I´ve asked around about this and noone seems to have a solution for me.
I´m running smoothstepper on my lathe and the spindle motor is a dc servo motor that´s rated to about 3000 RPM.
For some reason it just won´t go any faster than about 940 RPM.
It feels like i´ve tried everything.
In Motor Tuning i have velocity at max but it still won´t go faster.
I´ll soon throw my lathe in the trash if I don´t solve this.

Offline Dan13

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Re: Slow spindle on my lathe
« Reply #1 on: August 19, 2010, 11:57:42 AM »
It's not only the velocity under Motor Tuning that needs to be right to get the right speed, it is also the Steps per. Also check the pulley settings - set it to 1:1 and set the max speed to 3000RPM.

Dan
Re: Slow spindle on my lathe
« Reply #2 on: August 19, 2010, 12:38:14 PM »
How can i know what´s the right steps per?
I´ve already tried with different numbers in pulley settings but i never get more that 940 rpm.  Buuuhuuuuu    :O(

Offline Dan13

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Re: Slow spindle on my lathe
« Reply #3 on: August 19, 2010, 01:16:24 PM »
What is the line count of your servo's encoder? It would probably be a quadrature encoder so multiply whatever the line count is by 4 and that should be the steps per revolution.

Dan
Re: Slow spindle on my lathe
« Reply #4 on: August 20, 2010, 11:52:24 AM »
I tried that but i´ve tried it before and the magic number is 935.
The spindle will  not go faster. (I checked the rating and it´s 3600rpm.)
I put 4096 (1024 x 4) in steps per but there´s no improvement.
Does it really have to be this complicated?
Re: Slow spindle on my lathe
« Reply #5 on: August 20, 2010, 01:10:22 PM »
Finally solved it.
In the configuration of the "eprom" on the driver board the step multiplier was set to 0 so i changed it to 4.
Now I got speed... yeeeeaaaaayyy.
It´s strange though because i asked the guy who sells the cards if he had any idea of what was the problem
and he couldn´t figure that out.  :-\