[chalio]

I have a problem with the spindle turning off or not moving at all, i have to rotate the knob, that regulates the spindle speed to computer, several times and it wants to run but it quits. The switch is good, i tested it. So i am wondering if someone has experienced this problem and what it was the solution. i have seem some other post of members that want to change the spindle drive, but their machine is different than this one.

Would anyone explain how this works or give me a general idea of what to look for.

i have close to zero knowledge in electronics but i would like to lean so any help will be so valuable and really appreciated.

By the way the spindle doesnt work on Manual. When i choose the computer, it used to run no problem, but now sometimes it works and quits or it doesnt work at all. i can hear the solenoid engaging but nothings happens.

Thanks in Advance.

[Fastest1]

Even though you tested it, I still suspect the potentiometer.
In my experience on Dyna machines, the switch from CNC to manual usually only involves the ground.


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[chalio]

i replace the adjustable drive card and it seems working on cnc mode, but manual still doesnt work i did check the ground connection but everything seems good. what i should be looking for?

thanks.

[Fastest1]

You are checking it static with no load. I suspect the pot is burnt up. Try a new one as a test. Cheap and three wires. Or you might be able to milk it with some tuner spray. Try to clean the pot. Might work for a bit. https://youtu.be/njwi-GwJBzc

i replace the adjustable drive card and it seems working on cnc mode, but manual still doesnt work i did check the ground connection but everything seems good. what i should be looking for?

thanks.

[MakesThings]

There might be transient voltages feeding back from the drive motor and affecting the speed controller components from brush carbon buildup inside the motor. The carbon can buildup inside the motor and it will eventually short out the speed controller rectifier bridges completely stopping all motor function.

To prevent this take out the motor assembly, remove the brushes , shake the motor and position brush end down and apply vacuum to each of the brush holes one at a time, shake & tap motor on the bench and repeat vacuuming. Use a filter cloth of some type at the head of the vacuum to check for carbon residue. To completely disassemble the motor for a though cleaning the pulley must be removed and it is heat shrinked onto the shaft. Using a heat gun and bearing puller you can get it off, the plate will be get bent but it flatens out, ream out the pully so it will be a zero clearance fit on the motor shaft, it doesn't need to be shrink fitted.

It could also be a diode getting old that is changing it's resistance over time throwing off the circuit balance, or the OEM software is getting buggy. Clean that motor in any case, it will save you quite some grief in repairing or replacing the speed controller board.

[dan_the_welder]

I've had two of the speed control boards fail. I've also had all the relays in the control box fail. Doesn't sound line your problem though.

Take a look at that clear relay, that switches the motor between power and the braking resistor. The contacts may be arced up. That would be an intermittent problem. Mine failed that way.

I've never used the intellitech card or software, I've always used linuxcnc through an adapter board. Although since then I've completely replaced the drive box with one that I made from scratch that uses modular drivers with a separate power supply, industrial relays and a commercial DC motor control.

[MakesThings]

I've had two of the speed control boards fail. I've also had all the relays in the control box fail. Doesn't sound line your problem though. Take a look at that clear relay, that switches the motor between power and the braking resistor. The contacts may be arced up. That would be an intermittent problem. Mine failed that way. I've never used the intellitech card or software, I've always used linuxcnc through an adapter board. Although since then I've completely replaced the drive box with one that I made from scratch that uses modular drivers with a separate power supply, industrial relays and a commercial DC motor control.

Carbon buildup inside the DC drive motor will burn out the speed control board because the tranisent voltages from the carbon dusts short out inside the motor and overload the rectifier bridges & output diodes on the board, killing the speed control board. Shorting out the speed control board overloads the motor power supply board, that's why the motor power supply relay shows arcing. If the machine has high or unknown hours clean out the DC drive motor. The

[Saltynovice]

I have a problem with the spindle turning off or not moving at all, i have to rotate the knob, that regulates the spindle speed to computer, several times and it wants to run but it quits. The switch is good, i tested it. So i am wondering if someone has experienced this problem and what it was the solution. i have seem some other post of members that want to change the spindle drive, but their machine is different than this one.

Would anyone explain how this works or give me a general idea of what to look for.

i have close to zero knowledge in electronics but i would like to lean so any help will be so valuable and really appreciated.

By the way the spindle doesnt work on Manual. When i choose the computer, it used to run no problem, but now sometimes it works and quits or it doesnt work at all. i can hear the solenoid engaging but nothings happens.

Thanks in Advance.

Bumping this old thread instead of starting a new one. I am hoping the op may have found a solution or other new insight from anyone

Mine is completely original with functional jog and tool changing controls/motors

When I powered on the spindle the first time it turned about a quarter turn and stopped. I do get a relay click when powering it on and off.

I will be performing a motor cleaning for brush dust and spray clean the potentiometer per the video link above. I will try replacing the potentiometer if that doesn't work

I will also visually inspect the clear relay in the control box next to the potentiometer to look for evidence of arcing

If all that fails, is there a way to identify a likely culprit in the control box? Short of a swollen capacitor, my electronics troubleshooting is limited.

Should I expect to be able to find a local electronics guy who could troubleshoot and/or replace individual components on a board that have gone bad?

I have read extensively on users who have upgraded all of the electronic components to use modern cad/cam programs, and given the time/money/ effort, along with a lot of help from online parties, I could probably make that happen, but it's not required for my meager needs and i'd much prefer to go with everything stock if possible. I the equivalent version of their mill and have had great fun running it stock

Thank you!

[MakesThings]

Your problem has most likely resulted in the untimely death of many a Prolight 3000 lathe. What is happening is the sealed drive motor is shorting out internally from excess carbon residue from the brushes, which then fries the SCRs and diodes on the motor drive board, and stops the motor from working.

The motor must be removed, cleaned out, and the armature contacts resurfaced. The drive pulley is heat shrunk onto the shaft so once you make a backing puller plate for the drive motor mount and engage your puller assembly (don't half ass that procedure) use a heat gun to expand the pulley and remove it. You can use some wet sponge or rag to cool the shaft from behind the pulley to promote the thermal expansion difference of the procedure. I suggest reaming out the pulley to shaft size so there will be less drama in future maintenance. The pulley does not need to be heat shrunk to the shaft, my Prolight has had no problem after the repair.

The motor control board is a PCM21000 and the 6020L diodes on the board are replaceable with D8025L diode 800v 25A 4us 3 pin TO-220. I replaced 6,7, and 8 on the schematic.

The Prolight 3000 is a good CNC machine but repairing it is something that is more complicated than most can accomplish, so they die an untimely death at the hands of good intentions.

[Saltynovice]

Your problem has most likely resulted in the untimely death of many a Prolight 3000 lathe. What is happening is the sealed drive motor is shorting out internally from excess carbon residue from the brushes, which then fries the SCRs and diodes on the motor drive board, and stops the motor from working.

The motor must be removed, cleaned out, and the armature contacts resurfaced. The drive pulley is heat shrunk onto the shaft so once you make a backing puller plate for the drive motor mount and engage your puller assembly (don't half ass that procedure) use a heat gun to expand the pulley and remove it. You can use some wet sponge or rag to cool the shaft from behind the pulley to promote the thermal expansion difference of the procedure. I suggest reaming out the pulley to shaft size so there will be less drama in future maintenance. The pulley does not need to be heat shrunk to the shaft, my Prolight has had no problem after the repair.

The motor control board is a PCM21000 and the 6020L diodes on the board are replaceable with D8025L diode 800v 25A 4us 3 pin TO-220. I replaced 6,7, and 8 on the schematic.

The Prolight 3000 is a good CNC machine but repairing it is something that is more complicated than most can accomplish, so they die an untimely death at the hands of good intentions.

Wow, thank you for that thoughtful reply!

Getting the motor cleaned up is in my skill set.

I have many questions but will ask them as I go, and I hope you and others will continue to provide guidance.

I was able to remove both drive pulleys by loosening the set screws, applying a bit of heat, and yanking firmly with a set of channel locks after covering both sets of plier teeth with a small length of nylon tubing to protect the pulleys

The side guide walls of the pulleys are separate pieces that are friction fit and peened. I removed the outside one from each pulley to allow me to grip the main pulley body with the channel locks.

As you can see, I built a custom rolling table for the lathe, and it took four of us to get it up there. I will have to wait for more help before I can remove the motor, because turning it on its side on that high perch is a bit more than I think I can handle.

Am I correct that the motor will come off after removal of the four red circled screws?

I'm interested to see how worn down the brushes are. How much use before I find myself with another burned-out card? Are there low residue brushes? Other tips to minimize future risk?

After searching Google for the motor controller that you mentioned,PCM21000, I found a handful of shops online that offer mail-in repair for under $100. The price is right, and troubleshooting and replacing components on a board is not in my skill set.

Any thoughts on that plan? Particular shops that you would recommend?

Thank you again. This is a far less daunting task then I had expected, especially the insight on the specific motor controller board and it's probable repairability. That part seemed witchcraft to me!

[Saltynovice]

Also, the card in question is in the computer, yes, not the control box

[Saltynovice]

Upon opening both the control box and the computer, seems most likely the PCM21000 controller is integrated into the main board in the control box, as I don't see anything that resembles stand-alone controllers online. Picture one

Looking at the main board in the control box, I also don't see diodes that resemble pics I see of 6020L diodes online, and I do not have a schematic other than what is printed on the board. Picture 2, control box

Is there a schematic available online, or can you point out the location of diodes 6-8 in my picture?