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Stepper Motor

Posted by Anonymous User 
Anonymous User
Stepper Motor
December 11, 2008 05:19PM
Hello,

I am getting these motors for cheap, do you think that they are suitable for the Mcwire Setup?

[sparkycnc.com]

here are some specs

[www.parkermotion.com]

its the OS22B

tyvm

arun
sid
Re: Stepper Motor
December 11, 2008 07:06PM
I may be wrong, but 170V DC ? Sorry, I don't think they will be very happy with just the 12V we can deliver with our stepper driver.

Also they're rated with 2.2 Ampere when in serial mode, the driverchip is stable up to 2 Amps and even then it needs serious cooling!

I'd take a step back and look elsewhere personally.

'sid
Anonymous User
Re: Stepper Motor
December 11, 2008 10:08PM
I see what you mean, Thank you very much for the reply.

I was thinking about getting this to drive those steppers

[cgi.ebay.com]

they come with a power supply included,

what do you think,

Best,

arun
Re: Stepper Motor
December 12, 2008 04:22AM
'sid,
The voltage rating is the maximum voltage you can use with a chopper drive. It is simply determined by the winding insulation. You don't need to run them at that voltage unless you want to go extreamly fast.

They would work with fine the RepRap driver as long as the current is not set too high. The 2.2A rating is peak but the RMS is only 1.5A. When not micro stepping RMS and peak will be the same.

The torque is similar to to the Keling motors so the current only needs to about 30% of that for Darwin X and Y axes. McWire should run with even less current.

arun4444,
The drives on eBay would certain do the job if you want to spend that sort of money. As they give 170V they will go more than ten times faster than the RepRap 12V drive, but I doubt the Arduino could keep up with the step rate.


[www.hydraraptor.blogspot.com]
Re: Stepper Motor
December 12, 2008 05:01AM
I should add that 170V is quite dangerous and should be treated like mains wiring. I.e. double insulation and earth the motor casing.


[www.hydraraptor.blogspot.com]
sid
Re: Stepper Motor
December 12, 2008 06:25AM
Quote

The voltage rating is the maximum voltage you can use with a chopper drive. It is simply determined by the winding insulation. You don't need to run them at that voltage unless you want to go extreamly fast.
true nophead,
but from what I know from ordinary higher voltage DC motors (let's say a 150V DC Fan) they won't even start moving with around 9V and anything near 12V makes them turn very unhappily (slow and inconstant), I'd guess those steppers wont be very happy with such a low voltage too.

'sid
VDX
Re: Stepper Motor
December 12, 2008 07:40AM
Hi sid,

... my stepper-drivers are capable of 70 Volts and 6 Amperes, but i can drive 5volt/0,4Amp-steppers with them without problems - i have only to adjust the max. current.

When the motors are happy with 2.2 Amps current, then they will run with 2 Volts too.

The higher voltages are important when reversing the current through the coils - when your max. micro-stepping frequency at 2 Volts is maybe 4 kHz, then with higher voltage you can rise it to 30kHz or even more (dependant of the impedance and hysteresis of the coils).

But 2kHz would be fine for the reprap too winking smiley

Viktor
sid
Re: Stepper Motor
December 12, 2008 08:02AM
If you tried something close and it's working...

nevermind what I said earlier grinning smiley

'sid
Re: Stepper Motor
December 12, 2008 09:17AM
The 170V rating is not the continuous working voltage of the coil like you see in other stepper motor specs. If it was then the power dissipation would be 170*1.5A i.e. 255W. That would be a very big motor! It must be the insulation rating.

Odd that the resistance is not mentioned, although when using chopper drives, current and inductance are the important parameters. The fact that the inductance is low and the current high implies the resistance and continuous operating voltage must also be low.


[www.hydraraptor.blogspot.com]
Re: Stepper Motor
December 26, 2008 04:46PM
Hey all,

I've been looking at a set of three KL23H286-20-8B motors.
Here's the specs:
[www.kelinginc.net]
And the torque/speed curve:
[www.kelinginc.net]

There's not that much information there, but I was wondering what modifications would be required to the reprap driver boards to be capable of running them, or a similar motor. Or does this motor fit into the same category as the ones above, and can easily be run under peak voltage and current?

These are supposed to be used in a cnc/reprap, to explain the high torque. Of course, it might be too high for even cnc milling, so let me know what you think. I found them on ebay.

-Samuel
Re: Stepper Motor
December 26, 2008 05:05PM
They should work without any mods. If you use bipolar serial you can get the full torque. Bipolar parallel would be faster but you can't get the full current / torque.

Torque falls of faster with these motors than it does with the ones the RRRF supplies but as it starts off higher I expect the top speed for a given load is similar.

Being bigger and heavier the rotational inertial is higher so I expect the pull in rate (the maximum speed you can start at without any acceleration) will be less. Of course that also depends on the inertial of your load.

Edited 1 time(s). Last edit at 12/26/2008 05:06PM by nophead.


[www.hydraraptor.blogspot.com]
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