Dpdt switch to reverse old Craftsman motor?

[markba633csi]

This low-cost type can also be used in place of the "hockey stick" type- with a different hookup: (need several jumper wires)

https://www.amazon.com/Baomain-Positions-Terminals-Changeover-Control/dp/B01G6TEZKO/ref=sr_1_7?crid=BOT6ZQNQPGSQ&dib=eyJ2IjoiMSJ9.z6UfRuNa6RqwZY2DOz7InZh47kNZC1mFtuvlLvwmxQ51HNv_vNF9nfnqyYChVoDiaH8Aoy_jKiMlhTb7ubVFeWPN-KAoYmUNoKa2Tdx1LpT-7txKrXICfbOiSqfrygRxJLGxnpM17YEf4moOMH64IFZgVTi4CG9CviN5_4UW2cYGxV-syagKckQM_BKdFLNkszRIxtNHZaBVdKSfTeLWSmZjm1bnm8yIT7WVfugN3fRCD4ayZtbPxkkMoQ3uIoWFsrAGRb_nQKugDIm3pHILvNSw7XPa5pTNmB_LCw3Ow9k.R7QkuJ3vQFTAFRaFIR3Z524Pvaq7wkx1soDmmDnWHTs&dib_tag=se&keywords=reversing+switch&qid=1711292920&sprefix=%2Caps%2C1528&sr=8-7

 

[JustTrimitaLittle]

The great era of local hardware stores is over, I'm afraid. Pretty much have to order everything these days
Here are the two basic ways you could wire it: (RJ's would be the third way with a 3-pole toggle switch)
There are also alternate "drum" switches from China with a zillion terminals that require several jumpers
View attachment 484099View attachment 484101

Amen to that. 2 years ago I would have to walked into the electronics store we had here parts and knowledge in hand. Now you go to Lowe’s or HD and ask for something this specific and they just say it doesn’t exist.

So in theory this should work right?

 

[markba633csi]

Looks like a DPDT type (2 position)
Would not work as a single switch solution

 

[JustTrimitaLittle]

It can be done with a single switch but the switch has to be a 3pdt center off. The reason is that the run windings would otherwise always be energized, even with a center off switch. You are controlling three states with the switch. OFF, FORWARD, and REVERSE so you need the three positions. I used a switch like this on my lathe: It is completely configurable and can be used for single phase, three phase or dc motors.

https://www.amazon.com/gp/product/B07SWY67F2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

If you need a smaller footprint, one like this would work.

CUTLER-HAMMER EATON - 7613K2 - Switch, Toggle. 3PDT Center-Off.

CUTLER-HAMMER EATON - 7613K2 - Switch, Toggle. Contacts: 3PDT. Contact Ratings: 15Amp 125VAC, 10Amp 250VAC (1HP 1-2PH 125-480VAC, 1HP 3PH 125-600VAC). Actuator: Center-off ( 3 Positions maintained). Connection: Solder Terminals. Mech: Panel. Panel hole: 46.5mm long x 35.1mm wide x 21.3mm high...

www.electronicsurplus.com

note that this is true for an inductor motor with a start winding. A dc brush motor can be reversed with a simple dpdt switch.











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It must have been something I was reading about a dc motor when concocted that idea. I ended up just ordering a cheap 3pdt switch off Amazon that meets the power ratings. And if I can figure out how to wire it I might invest in a better one.

After I get this figured out next on the list is fabing up a slow speed pulley. I think I can do that one. I’m a bit more comfortable with mechanical over electrical.

Thank you for the help! It’s times like this that bring anti social in the real organic world doesn’t pan out well.

 

[RJSakowski]

It must have been something I was reading about a dc motor when concocted that idea. I ended up just ordering a cheap 3pdt switch off Amazon that meets the power ratings. And if I can figure out how to wire it I might invest in a better one.

After I get this figured out next on the list is fabing up a slow speed pulley. I think I can do that one. I’m a bit more comfortable with mechanical over electrical.

Thank you for the help! It’s times like this that bring anti social in the real organic world doesn’t pan out well.

The switch in post #12 doesn't look like a center off switch.

 

[OCJohn]

To reverse the motor direction, you need to reverse the start windings…

I don’t want to hijack @JustTrimitaLittle’s thread, but is there an easy way to identify the start windings in an old motor without markings or colors? I would love to have a reversing/3DPT switch on this…

 

[JustTrimitaLittle]

I don’t want to hijack @JustTrimitaLittle’s thread, but is there an easy way to identify the start windings in an old motor without markings or colors? I would love to have a reversing/3DPT switch on this…

View attachment 484121View attachment 484122View attachment 484123

I can chime in my info. Take it fwiw… not much. Lol. But if you have a multimeter and check resistance the start winding has a higher resistance.

 

[RJSakowski]

I don’t want to hijack @JustTrimitaLittle’s thread, but is there an easy way to identify the start windings in an old motor without markings or colors? I would love to have a reversing/3DPT switch on this…

The start winding will be in series with the capacitor and the centrifugal switch. Unless the motor is designed to be reversing, it is a non trivial task. I have done it to multiple motors. https://www.hobby-machinist.com/threads/reconfiguring-an-ac-induction-motor.103647/

 

[markba633csi]

Yes, you use an ohmmeter and locate the pair of terminals that "jumps" the needle each time you reverse/swap the probes.
The resistance should start low and then rise with each reversal of the probes.
That's your start leg pair; you're reading thru the start cap
You can use a digital meter also but it's easier with a needle type one IMO

In the picture, the start pair is either the pair with the power cord connected, or the pair that those are jumped to.
Could be either pair, but I'm guessing the latter

 

[markba633csi]

Just for completeness, here's another single switch option: (available on Amazon, post #11 above)