Spindle Motor Control

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justasking
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Joined: Mon Oct 31, 2016 10:58 am

Spindle Motor Control

Post by justasking » Wed Oct 18, 2017 10:53 am

What are some suggestions and opinions for spindle motor Speed Control. I have a small 3 axis bench mill that uses just a plain Jane ac/dc motor (1/10 hp I think) . I don't think I want to go with a high speed water cool motor with VFD for this little guy. The original rheostat had capacitors, diodes and resistor which I was thinking were for starting, but not for certain. I am having difficulty obtaining schematic or specs. Thanks for any suggestions.

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DICKEYBIRD
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Location: Collierville, TN

Re: Spindle Motor Control

Post by DICKEYBIRD » Wed Oct 18, 2017 2:27 pm

I'd use a tried & true KBIC-125. Cheap & tough as a boot. Used ebay unit is fine because many are replaced in the commercial world with newer PWM designs. The ol' SCR types are fine by me though. Here's one as an example but I have found them for as little as $25. https://www.ebay.com/itm/MADE-USA-TESTE ... SwBLlVV-D0

I also attached a manual for your perusal. They are adapted to different motors with a plug-in "horsepower" resistor. Doesn't have to be real close for our usage. HTH
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kbic_manual.pdf
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Milton in Tennessee

"Accuracy is the sum total of your compensating mistakes."

justasking
Posts: 7
Joined: Mon Oct 31, 2016 10:58 am

Re: Spindle Motor Control

Post by justasking » Wed Oct 18, 2017 3:25 pm

Thank you so much for the information. I will read through the manual to be sure it is with in my capability to install. Looks fairly simple though.

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DICKEYBIRD
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Re: Spindle Motor Control

Post by DICKEYBIRD » Wed Oct 18, 2017 3:57 pm

I forgot to say use the KB assuming your small mill has a typical permanent magnet DC motor like most Asian mills. It'll work great for those types of motors. I've never done it but they'll also work on shunt-wound motors as well but I'm guessing yours isn't likely to have one of those.
Milton in Tennessee

"Accuracy is the sum total of your compensating mistakes."

justasking
Posts: 7
Joined: Mon Oct 31, 2016 10:58 am

Re: Spindle Motor Control

Post by justasking » Wed Oct 18, 2017 6:22 pm

The motor is a little permanent magnet ac/dc motor with brushes. I call it a sewing machine motor because it is so small. It does great job for me doing little things. Attached is a picture. I will hopefuly be able to graduate to larger mill some day. Reading the manual I think this speed control will work fine for this type motor also.
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2M037_AS01.jpg

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Marty_Escarcega
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Re: Spindle Motor Control

Post by Marty_Escarcega » Sat Oct 21, 2017 9:34 am

I'm with Dickeybird, KB Electronics controllers work very well. I have them on two machines. Do keep in mind you have to buy a horsepower resistor that matches the HP of your motor for them. This tells the control to limit the current to the motor so it does not burn it out.

KBIC-120 on ebay can had pretty easily. They can be controlled with a potentiometer. Add the SI-5 Signal Isolator and they can be controlled with a 0-10VDC analog input from a CNC controller.

Marty
"Jack of all Trades, Master of None"

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