Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: jimpinder on July 16, 2007, 03:30:43 AM

Title: stepper motor driving speeds
Post by: jimpinder on July 16, 2007, 03:30:43 AM

Can anybody explain the relationship between "kernel speed" as set on the prots and pins page, and setting up the stepper motors.

I have two 220Ncm motors driving the main axis and cross slide on my lathe (A Warco). Even running light, i.e. not cutting, I seem unable to get the motors moving faster than 4" per min traverse speed. The machine cuts alright and everything else, but I would like to get the traverse speed up during G0 movements.

If I move up to say 6" per min - the traverse might run but the motors might then start missing steps and once the start missing the seem to carry on missing.

I have a 3 to 1 reduction on the drives so I need 48000 steps per inch, but divided down to seconds it is only about 1.6kHz which doesn't seem a lot.

The only other thing, of course, is the motors - perhaps these will not go faster - but they are brand new - 8 wire, but connected as bi-polar.

Any offers, please

Jim Pinder

Title: Re: stepper motor driving speeds
Post by: Brian Barker on July 22, 2007, 02:36:21 PM

Sounds like you would need to have bigger motors or amps to drive the axis faster :( if you endup with the slider all the way up and you need to get more speed that is when you would change the kernel Speed of mach3 to make the axis go faster...

Hope that helps
Brian

Title: Re: stepper motor driving speeds
Post by: jimpinder on July 23, 2007, 04:48:35 AM

Thanks Brian - I will carry on at the moment, and get the system fully functional before I start trying to make things go faster, I am still waiting for my dual driver card from cncsupply - I have been waiting about three weeks now. I think the firm in in the States - they must be coming by paddle steamer !!!