Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: xjdubber on January 14, 2007, 02:51:21 PM
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How do you properly size a stepper motor to an application? Working on converting a Laguna mill, really not quite sure how to size the motors? Was thinking of getting some in 700 oz range. Is there some rules about sizing at all?
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I don't know how big the mill is that you are talking about. Best bet for me
has been go with what is known to work. 800 to 1200 oz-in steppers for a
full size BP is comfortable.
I am running 200 oz-in servos, 4:1 reduction on a full size series 1 BP
and it will cut anything I give it. This gives me 800 oz-in at the ballscrew.
Servos also have a bit of reserve torque that you can tap for just a small
bit of time if needed.
I say go a bit larger with the steppers because if you "lose" a step
you will never know it, plus there is no reserve torque with steppers.
Of course you can gear the stepper to increase the torque but you may
be dissatisfied with the speed.
Scott
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Well speed is something im not to concerned about, a mill doesnt really have to run that fast.
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Well, what kind of reduction ratio are you thinking about?
How big is the mill?
Scott
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I have a Bridgeport clone and run 1780 oz. in. steppers with 1-1 gearing and .200 lead ball screw.
Brett
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i was thinking something like 4:1 and yeah its the same size as an average bridgeport
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This link may help some.
http://www.cs.uiowa.edu/~jones/step/physics.html
Brett