Old Woodfast controller info needed

[Louis Bonham]

Greetings:


I have an old (circa 1996) Woodfast M910, back from the time when Craft Supply used to import bare WF lathes from Australia and install US-made motors and electronics. CS stopped importing Woodfast lathes many years ago after they started being made in China. The power supply / controller on mine has flaked, and I need some ideas / info.


My lathe has a 1.5 HP Leeson (108092.00) permanent magnet 180VDC motor, stepped pulleys, and a power supply / speed controller that connects to the start button / stop button / variable speed dial on the front of the unit.


The power supply / supply controller on mine is 220VAC in, 180VDC out. When I hit the start button, the lathe runs for maybe 1/10 second and then cuts out. (Removing the cover from the controller, when the lathe starts you can see and hear a 220VAC relay closing.) Hitting the start button again doesn’t do anything unless you first hit the “stop” button (which resets the relay).


There is a sticker inside the power supply / controller housing that indicates that the board was replaced in 2003, and there is a handmade label on the outside of the power supply / controller identifying the apparent maker as “D/J Wood Sales, 206-487-6190.” (Online sources indicate “D&J Wood Sales” of Washington state went out of business in the early ‘00’s).

I suspect it’s probably just a triac or scr on the board that has gone out, but if I have to replace the entire controller, any ideas on what to replace it with, or who might be able to diagnose / repair the board?

[Richard Coers]

Old is 1996? Ouch! For a hobby lathe, that's barely getting broken in. I'd call KB Electronics and talk to them about this controller. https://www.kb-controls.com/product.sc?productId=11&categoryId=3

[Louis Bonham]

Thanks. Yup, this lathe will probably last until the next ice age -- nice and heavy. (Professional woodturner Steven Russell was the original purchaser; he sold it a few years later to another woodturner in the Houston area when Steve upgraded to a monster Oneway. That turner later sold it to me several years when he upgraded to a Stubby.)

At the time I posted the original message, I also took a longshot and wrote Craft Supply. While they didn't have any detailed information (after all, it's been almost 20 years since they imported / built Woodfast lathes for the US market!), someone there recalled that the control boards they used to use were made by Minarik. I pulled the board, and yup, it's a Minirak MM23001C, which are still on the market.

Even better, a bit of Google-fu reveals that Surplus Center has a stash of NIB ones for less than half the retail price!!

[David Walser]

Are you going to use the original enclosure and heat sink?

My Woodfast (much newer than yours at 1998) is also having problems. At times, the lathe simply loses power. It might stop completely or simply be a reduction in power. An electrical engineer friend tried to check out the controller and the motor with his multi-meter, but he could not find any faults in either. (Don't you hate intermittent electrical problems?)

[Louis Bonham]

Are you going to use the original enclosure and heat sink?

My Woodfast (much newer than yours at 1998) is also having problems. At times, the lathe simply loses power. It might stop completely or simply be a reduction in power. An electrical engineer friend tried to check out the controller and the motor with his multi-meter, but he could not find any faults in either. (Don't you hate intermittent electrical problems?)

If I replace the board, yes, I'll use the old enclosure / heat sink. Easy to remove the enclosure/heat sink assembly from the lathe (four nuts and bolts), and the board installs / uninstalls very easily from the enclosure [four screws and seven plug-in wire connections (spade/lug or pin connects)]. Take a picture before you start to remove the board so that you'll have reference on what color wires go where when you reconnect it.

This morning I also found a place in Georgia that troubleshoots motor control boards, including Minarik MM23001C's. (If you pull your board, there should be a label on the bottom that ID's which one it is.) You ship the board to them (USPS small box Priority Mail = $10.20), they'll test it for free, and if it can be repaired they'll give you a price. Place is EIC Repair:

https://www.eicrepair.com/

Mike Madsen is who I dealt with; very nice and responsive.

Comments on other forums indicate that motor control board problems often are just a $2 triac or SCR that has gone bad and needs to be de-soldered and replaced. I suspect the inhibitor (auxillary "kill switch") circuit on mine may be the problem. Just dropped the board in the mail to them; I'll report back on what they say / find. Worst case, I'll just buy a new one from Surplus Center ($135).

The folks at Craft Supply also suggested having the motor checked at an electrical motor repair shop. After I bought my lathe years ago, I did that and they replaced the brushes (my lathe has a Leeson 1.5 HP permanent magnet motor -- expensive but repairable) and cleaned it up. Worked like a champ after that.

The Craft Supply folks also suggest unbolting the lathe from the base (6 bolts) and sliding it down 12" or so, which gives you access to the box containing the start / stop / speed control switches so that you can test those with a multimeter. I suspect that if the potentiometer (speed control) has a fault / short, that could be causing the power losses. But my money is on the controller board being the problem.

[Reed Gray]

You might contact Odie over at the AAW site. He has a Woodfast lathe.

robo hippy

[Louis Bonham]

You might contact Odie over at the AAW site. He has a Woodfast lathe.

robo hippy

Thanks. I tried to register with the AAW website to post the question there, but apparently the site admins must approve every registration and they say they are taking 2-3 weeks to do so.

Again, hopefully the EIC boffins will figure out whether there is a problem with the Minarik board and whether it can be fixed economically.

[Louis Bonham]

FWIW, EIC Repair (http://www.eicrepair.com/) received and tested the controller board today, and reports that it does have some power section issues. So it looks like the mystery is solved.

Repair will be less than the price of NIB replacement board at Surplus Center (https://www.surpluscenter.com/Electric-Motors/DC-Motors/Motor-Speed-Controllers/90-180-Volt-DC-Variable-Speed-Control-w-Potentiometer-Minarik-MM23001C-000D-11-2269.axd), so hopefully all will be well soon.

[Louis Bonham]

Further update . . . .

EIC Repair did the job in one day, and the board is already on its way back to me. They report that two op amps on the board (LM324 and LM358) were fried. Those parts cost almost nothing, but having the equipment and knowledge to test and replace them (and to test the repaired board) is the trick.

They indicate that a power surge or fault in the motor is what probably fried the op amps. Thinking back, the last project I did before encountering this problem was using my Oneway Easy Core system to do some largish (12") bowl blanks from well-seasoned hunks of maple. That may have been pushing it with only a 1.5 HP motor. Any thoughts?

[Bill Howatt]

Can't really say so this is speculation on my part, but was the motor seriously bogging down when you were doing the coring? If not, then I wouldn't say it was the problem. Motor overloading is more likely to wipe out the power driving components rather than a lower level part of the circuit. However, there is no way of knowing how the overload protection was implemented.
Power surges are an often stated possible cause and IMO a lot of time, some component just failed because it just happens and that was the only reason.
I'll even go as far as to say sometimes a problem will be traced to a certain section and it is easier/cheaper to replace multiple active components rather than narrow it down any further. Depending on the design and the fault a tester may not be able to narrow it down further. As you said, the component's cost was cheap.

[Louis Bonham]

Thanks. It's been a while, but I do recall that the motor was straining (certainly compared to when I'd cored on a big Oneway with a 3HP motor, which was so powerful I doubt anything short of intentional misuse could bog it down). I think it happened after I had already cored a bunch of bowls and was doing the largest one on the second blank, so could have been a combination of the cutter dulling and the increased torque requirements of the larger radius that may have overtaxed the motor and fried the op amps (which are literaly <$1 parts). Lesson learned.

Anyway, my board is due to be delivered this afternoon, so hopefully all is about to be well. FYI, I sent the board to EIC Repair by Priority Mail last Thursday, so my drive out/drive in time for this repair was less than a week. Unless I'd been local to EIC Repair (Cartersville, GA) and could drop off / pick up the board at their shop, I really could not ask for any quicker service!