Stepper Motor replacement

[ckielcave]

Hello..

I have one of my stepper motor that doesnt work properly ... I dont know much about them...

My model is : SL42STH40-1684A

My question is : does all stepper (mostly) are 6-12-24 Volt ? Im asking because i see on ebay many 12-24 volt.. But if i look at data sheet of mine it say : Rated Voltage 2.8v ... does rated voltage and voltage is the same ?

Also i have a kossel printer with a MKS MINI board... My guess is that this board will take 12v stepper ?

I just dont wanna order the wrong one.. but i cant find exactly the one i need ...

Any one could link me to a compatible stepper motor ?

[printbus]

It may seem like a mismatch with a 12V supply, but you'd likely be best looking for a motor that matches the 2.8v 1.68a spec of your current motor, or at least is in that ballpark. The stepper motor driver takes care of the "mismatch" between your 12V power supply and the lower voltage motor. Places that sell motors for 3D printers should have something that would work.

Here's a good summary of stepper motors and the 3D printer application - http://reprap.org/wiki/Stepper_motor, including an explanation on why you want the lower voltage motor.

[ckielcave]

I cant find information about the MKS Mini V1.1 board ... im trying to find what would be the max voltage and amp for stepper driver.. because i cant find the same exact stepper driver ;(

[awerby]

Don't pay any attention to the nameplate voltage on your stepper motor; that has little or no relationship to the voltage you actually supply it with. The inductance of the motor is what you need to focus on when calculating the power requirement. So on that motor, you look it up on this chart: https://gzslmotor.en.alibaba.com/pro...ter_motor.html

It seems that the inductance is 3.2mH (which is quite high for a small motor like that). Using the formula: square root of the inductance times 32, you get an optimal supply voltage of 57.24v. That's what it needs to run at top speed. (The nameplate amperage is correct, though - it really wants to be able to draw 1.68 amps.). I'd say replace that motor with one that has a lot less inductance, so you can supply the right amount of voltage without blowing up your drivers. Look for one that has .6mH or less if you want to use that 24v supply.

Andrew Werby
www.computersculpture.com

[ckielcave]

i can buy from my work at mcmaster.. do you think this one would do the job ?

https://www.mcmaster.com/#6627t66/=14xcrpv

[awerby]

i can buy from my work at mcmaster.. do you think this one would do the job ?

https://www.mcmaster.com/#6627t66/=14xcrpv

I don't know about that one; it doesn't list the inductance. It does seem expensive for such a small, weak motor. This one looked better to me: http://www.phidgets.com/products.php?product_id=3303_0 - at least it's more affordable.

[ckielcave]

True.. its cheaper .. ill have to try it out...

isnt 2.5 amp to high ?

[awerby]

The more current the motor can handle, the more torque it will generate. But I don't know whether your drives will be able to support motors that draw 2.5 amps; you'll have to look that up in their spec sheets.

[ckielcave]

i wrote MKS mini v1.1 board manufacturer and they told me max amp : 1-1.4 ...
weird because the stepper motor that came with the kossel are rated at 1.68 amp