"Found" stepper motors - no datasheet available

I came by 4 Singer Kearfott Variable Reluctance stepper motors a long time ago. Item ident 05088 CT 40195009 EXTEL CORP P/N 22041E 24 volt

They have 5 wires, red, black, yellow, orange, brown.

Resistance from the black wire to all the rest is about 75 ohms.

Question: Are they any good? Can this be used to calculate power requirements? Any guesses as to which ones might be 1,2,3,4? And torque output?

I plan to make a drawer-slide style CNC sometime in the future and would like to use these while I am testing out my theories.

I will probably have to buy something better if I actually want to do something useful with it. In the meanwhile, these are free.

Any help gratefully.................etc. John

All I know is that 5-wire stepper motors aren't compatible with bipolar stepper drivers whereas a 6-wire motor can usually also be used as a 4-wire motor.

I have seen Threads here about using 5-wire steppers. I think they were generally low powered motors so I don't know if the drive mechanisms used would be suitable for your more powerful motors.

One issue to consider is that if you decide to replace the motors in future you will probably replace them with bipolar motors that will also need new driver boards and probably different software.

...R

http://www.ieeecss.org/CSM/library/1981/dec/w29-31.pdf

From a trade magazine by the looks of it, may help.

Also listed on ebay.

Tom...... :)

TomGeorge: http://www.ieeecss.org/CSM/library/1981/dec/w29-31.pdf

From a trade magazine by the looks of it, may help.

Also listed on ebay.

Tom...... :)

Thanks, Tom. I read the article.

"The CT4 0195 009 is a four-phase unit that features 24 steps per revolution, 7 inch-ounces holding torque, and a maximum stepping rate of 500 steps per second."

Wow! 7 in-oz of torque! I hope it doesn't rip the equipment apart with all that power! Sounds like I will need a 32 threads per inch leadscrew if I actually want to move anything with it. 24 steps per revolution, 500 steps per second, 32 tpi = god-awful slow. :D

But free!

Now if only a brilliant engineer can tell me about how big of a power supply I will need.

Thanks again, Tom

John

That is a four phase unipolar motor, which means that two windings are usually activated at the same time. The current per winding = 24 V/75 ohms = 0.3 A, power per winding = 24^2/75 = 8 watts (roughly). A very simple four transistor unipolar stepper driver will work fine. The motor will run on lower voltages but provide less torque.

You will have to determine the order of winding activation by experiment. For reference, see this http://homepage.cs.uiowa.edu/~jones/step/

jremington: That is a four phase unipolar motor, which means that two windings are usually activated at the same time. The current per winding = 24 V/75 ohms = 0.3 A, power per winding = 24^2/75 = 8 watts (roughly). A very simple four transistor unipolar stepper driver will work fine. The motor will run on lower voltages but provide less torque.

You will have to determine the order of winding activation by experiment. For reference, see this http://homepage.cs.uiowa.edu/~jones/step/

Thanks for the link. It is very informative. I know just enough electronics to be dangerous to devices and this treatise is written well enough for me to understand it, mostly.

Based on all this, I am ordering:

1 - 24V DC 2A power Supply adapter (brick style) 5 - 5pcs ULN2003 Stepper Motor Driver Board (1 spare)

Thanks, John

OldSalt1945: Wow! 7 in-oz of torque! I hope it doesn't rip the equipment apart with all that power! Sounds like I will need a 32 threads per inch leadscrew if I actually want to move anything with it. 24 steps per revolution, 500 steps per second, 32 tpi = god-awful slow. :D

But free!

Variable reluctance motors are pretty poor performers compared to modern neodymium-magnet hybrid steppers. They are cheaper as only copper and iron are needed, no permanent magnet materials. Rare-earth magnets didn't exist in 1981...

A good NEMA23 modern stepper has 200 steps/revolution and 3 N-m of holding torque.

Riiiiiiight. And only 75 bucks each.

http://www.ebay.com/itm/Nema-23-CNC-Router-Stepper-Motor-2-Phase-4-Wires-GB23H2112-30-4B-Dual-Shafts-3Nm-/141212223870?pt=LH_DefaultDomain_0&hash=item20e0e7897e

Champagne tastes; beer budget.

Recent technological advances are impressive. Things have advanced remarkably since the Stanley Steamer I drove as a young man. XD

John