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Mach Discussion => General Mach Discussion => Topic started by: ihugh on February 26, 2008, 12:57:30 PM

Title: 5 phase stepper and Mach 3
Post by: ihugh on February 26, 2008, 12:57:30 PM
Hi Guys

I'm a newbie to the world of Mach 3, so I'm excited to get started!

I have a pretty simple application: I want to use a 5 phase stepper and Vexta driver to turn a ball-screw driven linear slide.

What is the smallest step I'll be able to move? (degrees of rotation)

Any advice?

 :)
Title: Re: 5 phase stepper and Mach 3
Post by: jimpinder on February 26, 2008, 02:03:21 PM
You seem to be getting things in a bit of a twist. The "steps" are nothing to do with Mach 3, they all depend on your motor and driver, If you have the motor and the driver, then you can find this out yourself by connecting up the motor and driver, then putting a number of pulses into the "step" input of the driver card, and seeing how far the motor moves. The advantage with a stepper motor is that it will move for one step. So you can mark the output shaft, then put pulses into the motor. The shaft will move round step by step until it comes back to where you started. You could even use a push button to put the pulses in.

What Mach 3 does need to know is how many "pulses" therefore the number of "steps" Mach 3 has to put out to drive your axis either 1mm or 1 inch, depending on which measurement your wish to set up in.

I have not heard of a 5 phase stepper, most are four, or two  - but for example - my drivers are set to 1/8 step, my motors need 200 steps per rev, I have a geared down drive to my axis of 3 to 1, and the axis has to turn 10 time to move one inch. Therefore I need 8 x 200 x 3 x 10 = 48,000 pulses to move one inch. As you can see then, my best resolution is about 1/5th of a thousanth of an inch.

If this a a bit difficult to work out, there is a setting system built into Mach 3 to set the correct number of "pulses per unit" when you are setting up each drive (all drives need not be all set up in the same way).
Title: Re: 5 phase stepper and Mach 3
Post by: Vicke on August 20, 2008, 04:09:45 PM
Berger Lahr was made 5 phase steppers. My lathe have 2 of this, from -80
Title: Re: 5 phase stepper and Mach 3
Post by: Steve_B on July 07, 2009, 01:32:44 PM
I am just starting & I have Vexta 5 Phase motors. Did you get yours set up?
Title: Re: 5 phase stepper and Mach 3
Post by: mr.c on July 07, 2009, 05:47:39 PM
I have been using Vexta 5 phase motors on my Hardinge HLVH conversion. I am at 1/2 step which requires 1000 step pulses per revolution of the motor. Movement depends on the pitch of your ballscrew.
I am direct connected to 5 turn per inch ballscrews so 5000 pulses equal an inch.
Or .36 degree rotation per pulse.
Title: Re: 5 phase stepper and Mach 3
Post by: jimpinder on July 11, 2009, 04:55:12 AM
Mr C -

I,ve not heard of 5 turns to the inch ball screws. I have just fitted some 5mm pitch ball screws on my lathe (the previous set were Acme threads at 10 turns per inch.) The back lash is much reduced with the new ball screws.

Just a check ( and I am sure you will have done it) - are your 5 truns per inch actually that, or are they 5mm pitch ball screws - which will be short 0.4mm each 5 turns. I am afraid some retailers are not as precise as they should be when selling these thongs.

Mind you, I hadn't heard of 5 phase stepper motors either !!!
Title: Re: 5 phase stepper and Mach 3
Post by: Hood on July 11, 2009, 06:46:14 AM
Jim  0.200" lead is very common in machine tools, well in the uncivilised Imperial countries anyway ;D

Hood
Title: Re: 5 phase stepper and Mach 3
Post by: mr.c on July 11, 2009, 11:05:39 AM
They are in fact 0.200"/turn ballscrews. This is a conversion that I did a number of years ago. And yes I have verified that that is the right pitch.
Title: Re: 5 phase stepper and Mach 3
Post by: jimpinder on July 13, 2009, 03:00:13 AM
Yes - OK -  our plaster board and plywood still comes in 8ft x 4ft sheets - they call it 2400 x 1200 now. The trouble is some times it is that size, other times it is the old 8 x 4.

We, in UK try to be everything to everybody, I think - but I live and learn, 5 phase motors and 0.2inch pitch - who would have though of that!!! ??? ???