Delta scroll saw help.

[abunaitoo]

Got a Delta 40-650 Q3 scroll saw for free.
It didn't work.
Suppose to be a real good one, so why not.
Started to check it today, and got it to kind of work.
Not really, but it moves.
If I turn the speed control, the motor will jerk on and off.
I'm thinking the board is bad. PWM.
Brush motor, but I couldn't get it to spin by itself.
Did check the brushes, and both are good.
Two wires got to the motor, and two wires go to something on the back of the motor.
I'm thinking some kind of speed sensor????
Found a board on evilbay for a ok price, so ordered it.
Just hope the motor is ok.
Any suggestions/comments?????

[JimB..]

That’s a DC motor, first thing I’d check is the speed controller, rheostat, it may just be dirty/corroded. Unplug unit, turn the knob back and forth through it’s full range of motion a couple dozen times, then plug it in and see what happens.

[abunaitoo]

Did that already.
Thought it was dirty, so turned it to see if it would help.
It didn't.
Did take it out, and it looked clean.
No corrosion.
When I get it to start moving, it just cycles on and off.
Not moving the knob.
Checked the board for any corrosion or burnt out circuits.
None found.
A red light on the board comes on when the power is on.
But unless I move the knob, nothing happens.
Interesting.

[Armorer77]

I don't know what controller Delta uses but , variable speed controllers can burn internal . M ake sure you get the right size , 5 or 10 on the rheostat .

[MaryB]

It wouldn't hurt to clean the rheostat with a good electronic cleaner, make sure it is okay for volume controls/poteniometers

[DME72]

go online and lookup scrollsaws.com. rick is a wealth of info on scrollsaws. plus he has used that saw alot. he even has a phone number on his website if you want to call and talk with him. he should be able to tell you what is wrong with it.


doug

[abunaitoo]

Thanks
I'll check it out.

[lavenatti]

Potentiometers are typically a wiper arm connected to the knob. This arm makes contact with a semicircle of resistive material "painted" on a substrate.
If the design is open enough to see this resistive material you may be able to apply a fix. I've done this several times and it usually works ok.
Mix powdered graphite with a little motor oil, make a thin paste.
Apply a tiny amount directly to the resistive material and turn the knob back and forth to spread it all the way around.
This, if it works, will fill in tiny cracks in the resistive material that may be causing a problem.

If it helps you've found the problem. I've had this fix last a long time.

[abunaitoo]

Controller is suppose to be on island, and headed to the post office.
So might be here tomorrow.
Sure hope it's the problem and not the motor.
It's a PWM, so I'm thinking it has failed.

[bangerjim]

When all else has failed, as it usually does with old stuff!, (I quit buying old used stuff of any kind years ago!) check out the motor & controller packages at www.littlemachineshop.com.

I have used a couple of those for a Sherline and other lathes and they are GREAT! Just have to do some adapting of the mountings and pully.

banger

[abunaitoo]

Control came today.
I hooked it up on the bench.
Took the motor off earlier.
It works!!!!!!
Will put it back together tomorrow, if I have time.

[myg30]

Glad the controller was the issue and you have it working now. Thank you for posting this. I’ve been following the thread with anticipation of finding another scroll saw like yours.
Enjoy and watch them fingers.

Mike