Help needed with Orac lathe!

[plan_b_racing]

Hello everyone, I recently purchased an Orac lathe and I’m having difficulty getting it to work correctly.
The issue I’m having is that it is not moving in ether the X or Y direction but everything else is working including the spindle speed control. I have checked the fuses located at the back of the machine and they all appears to be ok.

I then removed the panel on the front of the machine to reveal the stepper driver boards. On each stepper driver there appears to be 4 leds but none of them are lit (are they meant to be?).

I thought it could be a power issue so I checked to see if it was getting power to the drivers. There is a brown wire running to one and a red wire running to the other board which i believe to come from the power module. They both read aprox 58v. I don’t know if this is the correct voltage for them?
This is as far as I have got.

Any help would be appreciated.
Thanks, Oliver

[Martin]

Is it on a limit switch? If you look under the front panel you should find 2 switches. Press & hold the one in the center & then jog away from the limit switch.

[plan_b_racing]

Thank you for the reply CNC Guru but I’m afraid that I have tried that. It will not work in ether in manual or when I program it with a tool path.

Could anyone tell me what voltage CD20 stepper drivers require? I have 58v going to them but from looking at the CD20 user manual on this site there is meant to be a 24v supply going to them. I have checked for this on the pin outs on the stepper board but there is no 24v reading? Could anybody tell me if it is meant to have this supply voltage of 24v or am I barking up the wrong tree?

[angel-tech]

58v is a touch low, they normally run at 65v ish but i expect it's within tolerances. Are the steppers locking up, if not check the drives are fully home in their sockets (only check this when the power is off). Also open the back panel and check the multiway block connector is together.

PS DO NOT DISCONNECT THE DRIVES OR MOTOR LEADS WHEN THE MACHINE IS ON

[plan_b_racing]

The steppers don’t appear to be locking up and the multi-way block is connected. Could you tell me what voltage I should expect at the multi way block for the steppers?

I have traced the 24v terminal from the stepper drivers back to the supply regulation board PC1601. I have 24vac coming in to the board at terminals 1 & 2 block ‘B’ but I don’t have 24vdc coming from terminals 1 block ‘A’ (this is going by the wiring schematic). I believe I have a fault with the L7824cv voltage regulator on the board.

Could this be why I’m having a problem with the stepper drivers or do you think this could be an unrelated issue?

[Martin]

Looking at the drawings you should have 24 volts dc on terminals 1 & 2 (PC1601 board, Block A) & 12 volts dc on terminals 2 & 3.

None of the electrical drawings seem to show the drive voltage for the stepper drive but on the CD20 manual it shows it at between 24 volts & 85 volts dc.

[plan_b_racing]

Thank you for your help so far CNC Guru. I’m finally getting some were now. I have found that one of the driver boards have failed and have been pulling the 24v supply voltage to both drivers down. Once I had removed the faulty board on the Y axis the board on the X now works fine.

Two problems I’m having now are;
1, I need to replace/repair the faulty board
2, I’m having an issue with the Y axis motor.

I have swapped the good driver between the X and Y axis and have found that the X axis is working fine and moves in manual mode but when i put the driver board on the Y axis the motor locks up but will not move in manual mode. I have tried the jog button but still no joy.

Any Ideas would be appreciated.

Regards,
Oliver