spindle control on harbor freight 7x10

[DICKEYBIRD]

Here you go. I simply used the two onboard relays which are controlled by Output 1 (Forward) & Output 2 (Reverse) to switch the KBCC upon M3/M4 commands. It must be simple...I actually got it to work the 1st time I tried!

[galyion]

Thank you for for the help. I got my kbc-125r and KBSI-240D in today. Everything is wired up and working.

[DICKEYBIRD]

Thanks for posting about your success Jeremy; good to hear. You certainly are a lot faster than me at wiring this stuff!

[galyion]

wiring is a mess. everything is screwed to a 2x2 piece of mdf behind the lathe. still needs some tuning. they sent a 1/2hp resistor instead of the 1/3 i needed so im not doing the fine tuning yet.

[DICKEYBIRD]

I don't think the resistor will make much difference as far as final adjustments/tuning goes. I think the resistor controls the maximum amperage available from the controller to the motor under stall conditions. You're not likely to let it work that hard. You can run it & fine tune to your liking, then install the proper resistor when you get it.

Seasoned electrical guys, please sing out if I'm off base here.

[ScotY]

I love my KBDD setup! Works great and pretty easy to install. Only spent about $100 for all the parts used off eBay. Looks like heavy duty stuff and probably easy to repair if a part goes bad. Thanks, Milton, for recommending the setup and for the wiring help!

[DICKEYBIRD]

I love my KBDD setup! Works great and pretty easy to install. Only spent about $100 for all the parts used off eBay. Looks like heavy duty stuff and probably easy to repair if a part goes bad. Thanks, Milton, for recommending the setup and for the wiring help!

Great news Scot; thanks for posting!

[martyscncgarage]

Great to hear it worked out!

[tkbot47]

Hello, here's how I control the spindles on an ORAC lathe & a (under construction) mill. Both have Acorns, KBCC-125R (R for reverse) SCR speed controllers, KBSI-240D isolators and PM DC motors. They both have a manual/automatic toggle switch & a KB 5K potentiometer when manual speed control is desired. In automatic, Acorn's 0-10V analog controls the desired speed in forward & reverse very accurately.

The KBC-125R has all relays, braking resistor, heat sink & whatever elecktrickery is needed to do what you want. They know their stuff! You'll have to discard your Chinese speed control but you could sell it on ebay. Both the KB units are available on ebay used for very little money. That's my 2 cents worth.

Here's link to what I did: viewtopic.php?f=60&t=1594&p=10067&hilit=kbcc#p10067

Dickeybird,
I mentioned this later in the original thread, but wanted your take on it. I have everything working properly with the 125R and 240D per your schematic (thanks for that), but I notice you mention that the acorn is controlling the desired speed very accurately.
I'm not getting that sort of speed accuracy on my G0765. I have acorn set for 100 min and 2300 max. Low speeds below 1000 are too low and high speeds are too high, ie setting 200 gives about 160 and setting 2300 gives about 2600. How can I get this more linear with acorn and 125R/240d trimpot adjustments? What's your secret?
Also, do you ever get "surging" of the motor speed that comes and goes? I am wired with 18 gauge, but I still get it occasionally, not sure why. Can the stock Grizzly DC motor achieve that sort of speed uniformity?

[DICKEYBIRD]

"Very" accurate isn't a true statement in retrospect; sorry for that. That implies close to dead-on accuracy. I should've used "fairly" or "reasonably". Very close speed control would need a servo motor or VFD.

Having said that I am getting better results than you are. I'll check mine later today & get back to you. I recently took some stuff back apart on it for some improvements but it won't take a minute to put a couple things back together enough to check spindle speed. I don't see surging with my setup. That sounds like an adjustment on the 125 board. The manual covers adjustments pretty well.

I wouldn't worry about 100 rpm since you won't get enough torque for useful work on the large diameter stock that would need that low a speed... unless you're cutting wax or marshmallows.