Spindle motor reversing relay/contactor

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ScotY
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Spindle motor reversing relay/contactor

Post by ScotY »

Anyone have recommendations for a relay or contactor to switch the motor on my mini lathe? I believe it’s a DC motor rated st less than 1/2 hp. Milton says he thinks the motor controller is a copy of the KBIC 240-D unit. I’m thinking the motor runs on around 100vdc but when switching directions, I would assume the voltage should be zero, or close to it. I believe I should be using Acorn’s onboard relays to control another larger relay, which would then be wired to the motor. A wiring diagram would be very helpful. :D
Gary Campbell
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Re: Spindle motor reversing relay/contactor

Post by Gary Campbell »

Scot...
There are uncountable sources for these relays. I am assuming your DC motor will draw around 5 amps, so I would use a 10 amp DPDT relay with a 24VDC coil, similar to this one: http://www.factorymation.com/55-32-9-024-0000 Don't forget to order a socket for whichever you buy.

Relay to reverse DC is fairly simple:
DC Reverse.JPG
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ScotY
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Re: Spindle motor reversing relay/contactor

Post by ScotY »

Thanks, Gary...that helps a lot. I found a diagram elsewhere and it was quite confusing. I’m assuming the “DC power from relay” is actually from the speed controller?

I’m going to assume the voltage rating on the relay is not too critical? Seems most of the one’s I’ve seen are rated at X amps at something like 120 or 240 vac. Since it’s switching DC, the current rating would be lower, or maybe not even specified. Since I’m assuming the motor is stopped (and no voltage coming in to the relay) I am also assuming it’s safe to not be concerned about an inadequate or non-existent DC rating?
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Re: Spindle motor reversing relay/contactor

Post by DICKEYBIRD »

Hiya Scot, the DPDT reversing relay setup will work for sure. After investigating the additional circuitry needed to prevent damage from accidental change of direction commands I took the easy way out & got a KBCC-125R control. The "R" means reversing and it handles direction change, heatsink, dynamic braking....the whole enchilada all engineered by KB. It works like a dream & they do show up on ebay at very reasonable prices from time to time. You can type in M3 S2000, M4 S2000 over & over & it spins up to full speed, *clack* brakes to full stop reverses to full speed *clack* brakes to full stop, etc, etc easy-peasy. No danger of burning up anything if you forget an M5. A valuable asset to have if your smoke-letting skills are like mine. :shock:
Milton in Collierville, TN

"Accuracy is the sum total of your compensating mistakes."
ScotY
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Re: Spindle motor reversing relay/contactor

Post by ScotY »

Hi Milton,
Thanks for the info. I may end up trying one of those controllers at some point...sounds pretty cool. However, if I can get the DMM servo working on my mill, I may get another one for the lathe.
ScotY
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Re: Spindle motor reversing relay/contactor

Post by ScotY »

DICKEYBIRD wrote: Fri Dec 29, 2017 7:14 pm Hiya Scot, the DPDT reversing relay setup will work for sure. After investigating the additional circuitry needed to prevent damage from accidental change of direction commands I took the easy way out & got a KBCC-125R control. The "R" means reversing and it handles direction change, heatsink, dynamic braking....the whole enchilada all engineered by KB. It works like a dream & they do show up on ebay at very reasonable prices from time to time. You can type in M3 S2000, M4 S2000 over & over & it spins up to full speed, *clack* brakes to full stop reverses to full speed *clack* brakes to full stop, etc, etc easy-peasy. No danger of burning up anything if you forget an M5. A valuable asset to have if your smoke-letting skills are like mine. :shock:
Hi Milton,
Would you be able to post a diagram of how you have the KBCC-125R wired up to the Acorn and your lathe? I’m thinking about picking one up. My lathe uses a toothed timing belt for drive. Do you think that will survive?
DICKEYBIRD
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Re: Spindle motor reversing relay/contactor

Post by DICKEYBIRD »

Unfortunately I don't Scot. Drawing schematics is not my forte after suffering a stroke a couple years back. Even simple schematics tax my remaining mental powers.:oops: I can get things working but absolutely suck at trying to draw it out on paper.

Fortunately KB does a good job and I just picked the appropriate setups from their manuals. I used the setup shown in the Forward-Brake-Reverse Switch drawing in the KBCC-125R manual and switched it using the 2 onboard Acorn relays. The speed control setup is shown in the KBSI-240D manual. I used the drawing: "FIGURE 6D – AUTO/MANUAL OPERATION WITH POTENTIOMETER ON KBSI INPUT" option shown on pg 11 to keep a manual/automatic function. It works well.

After reading your posts I'm sure you won't have any trouble at all following the KB info. :)
Attachments
KBCC-125R Manual.pdf
(1.97 MiB) Downloaded 135 times
KBSI 240D Manual.pdf
(1.33 MiB) Downloaded 143 times
Milton in Collierville, TN

"Accuracy is the sum total of your compensating mistakes."
DICKEYBIRD
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Re: Spindle motor reversing relay/contactor

Post by DICKEYBIRD »

Yes, the timing belt is fine although I prefer grooved belts that can be run at whatever tension is needed to support my level of experience. In other words, a "poor man's clutch" to prevent the carnage in a crash.
Last edited by DICKEYBIRD on Wed Jan 03, 2018 4:28 am, edited 2 times in total.
Milton in Collierville, TN

"Accuracy is the sum total of your compensating mistakes."
DICKEYBIRD
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Re: Spindle motor reversing relay/contactor

Post by DICKEYBIRD »

oops I meant edit not quote:
Milton in Collierville, TN

"Accuracy is the sum total of your compensating mistakes."
ScotY
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Re: Spindle motor reversing relay/contactor

Post by ScotY »

Thanks, Milton. I’ll do some reading. :lol:
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