Re: Q's for the stepper experts.
Posted by
Tony Jeffree
on 2001-05-16 00:38:56 UTC
You didn't say what was going to be hanging on the end of your 1/2"-10 ACME
leadscrew, but my immediate reaction would be that you may need to drive it
via a reduction drive with motors that are only 70-80 oz/in. My Taig mill
originally had 140 oz/in motors on 1/2"-20 leadscrews; I would not have
wanted to run it with smaller motors, and have now upgraded to 200 oz/in.
I suspect the stepper motor gurus will advise you to run the motor parallel
wired, in order to minimize the inductance of the windings as seen by the
chopper drive (gives faster current rise time for a given supply voltage).
Regards,
Tony
At 00:43 16/05/2001 +0000, you wrote:
leadscrew, but my immediate reaction would be that you may need to drive it
via a reduction drive with motors that are only 70-80 oz/in. My Taig mill
originally had 140 oz/in motors on 1/2"-20 leadscrews; I would not have
wanted to run it with smaller motors, and have now upgraded to 200 oz/in.
I suspect the stepper motor gurus will advise you to run the motor parallel
wired, in order to minimize the inductance of the windings as seen by the
chopper drive (gives faster current rise time for a given supply voltage).
Regards,
Tony
At 00:43 16/05/2001 +0000, you wrote:
>I have a question for those who understand the nature of the beast. My
>reading has left me a bit confused and maybe some of you can set me
>straight.
>
>First the background. I have four (older but new) Astrosyn 5V 1A 70-80 oz.
>in. steppers I want to drive in bipolar mode for a home built engraver (no
>milling) I have not been able to find data on these older (designation)
>astrosyns. They will be pushing 1/2"-10 Acme screws except for a forth axis
>which will come later on if all works out. The current rating from what I
>understand is usually given for the unipolar rating with the bipolar rating
>being at 70% of this (got that from some compumotor data). Please correct me
>if this is wrong.
>
>Now with that said, I also see in some of this compumotor literature that
>the windings of these six wire steppers can be run in series or in parallel.
>
>Series hook-up being:
>1A - Red
>1B - Red/Wh
>2A - Grn
>2B - Grn/Wh
>NC - Wh, Blk
>
>Parallel hook-up being:
>1A - Red
>1B - Blk
>2A - Grn
>2B -Wh
>NC - Red/Wh, Grn/Wh
>
>I'm assuming to run with a bipolar chopper drive I would want to run with a
>series connection. Is this a correct assumption? If so what current limit
>setting should I be using using on each drive for each motor if the above is
>incorrect?
>
>My next question is has to do with the (up to) 2A drives I'm looking at.
>They will take a 12VDC to 18VDC source for the motors.
>
>What voltage/current for my power supply should I be looking at to drive all
>4 of these motors with a 5V tap off of the main supply?
>
>I want to give thanks in advance for all replies,