Yet another Techno Isel Lathe Refit Using Centroid Acorn and Teknic Clearpath Drives

[carbuthn]

Thanks Marty,

That is what I thought, but could not find it explained anywhere.

My lathe has five micro switches installed on it, one on each end of the X and Z axis. One that trips before it hits the tailstock. They are wire by axis right now but I could separate and add separate Home switches.

I think I will try the soft limits.

Chuck

[martyscncgarage]

Home all works very well....

[carbuthn]

I have separated the switch for the tailstock from the four switches that are installed on the X and Z axis, two of which will be used for HomeAll (other two will remain but not be used unless of mess up the homing direction. I will set positive and negative soft limits for both X and Z axis.

Thanks for the help,
Chuck

[carbuthn]

I made progress with the lathe, but I am having trouble with moving the ClearPath servos with using the Acorn control.

• I have tested the LimitAll (mechanical micro switches), input turn red when switch trips.
  The Inductive Proximity switches work, but not mounted yet, they do set home when the switches are moved by hand.
  The E-Stop indicates properly on the display when the switch is pressed/reset.
  The Drive Fault seems to work correctly with the display, set to Servo On in the servo for HLFB's.

The servos run correctly when driven by the MSP software.

I tried everything I found on the forum regarding the ClearPath servo.

Thanks in advance,
Chuck

[carbuthn]

Additional Files

[carbuthn]

One more file.
Sorry that there are so many.
Chuck

[Richards]

I wonder if you're having the same issue that I had. I used the Acorn's NoFaultOut signal to turn on a contactor to turn on the power supply for the ClearPath servo motors. (Relay output 3.) When I pressed Cycle Start, the Acorn asserted the enable signals for the motors; however, I constantly had Axis?Fault (where ? represents Axis 1, Axis 2 or Axis 3, randomly). What seemed to be happening was that the Acorn asserted the NoFaultOut. The power supply was turned on, but because the Acorn's enable signals were inactive, the ClearPath motors' fault signal signaled a fault condition to the Acorn. When Cycle Start was pressed, the Acorn's enable signals were asserted, but the Acorn immediately checked the Axis?Fault signals instead of waiting for the delay that I entered in the Wizard. Gary Campbell suggested that I not use the Acorn's enable signals, but to connect each ClearPath's enable signal directly to 24VDC Ground. Since I was only using one of the three available poles on the contactor, I ran the 24VDC Ground signal through the contactor so that when the power supply for the ClearPath servos was turned on, the enable inputs to the servos were also asserted. That fixed the problem. Now when the NoFaultOut signal is asserted by the Acorn, the contactor turns on, the motors lock (enabled) and everything works. I made one additional modification. I installed a self-latching circuit to the contactor that controls the ClearPath power supply so that I have to manually press the start button to turn on the power supply. The NoFaultOut signal is still in the circuit so that if the Acorn gets an E-Stop command, it unasserts the NoFaultOut signal and the contactor turns off and stays off until the NoFaultOut signal is reasserted AND I have pressed the start button on the self-latching circuit. Adding the self-latching circuit prevents the power supply from being turned on/off/on too rapidly.

At this point, I'm not using the Acorn's enable signals. I would like to use those signals, but I'll have to use the work-around for the time being.

[carbuthn]

Mike,
I don't believe that it is the same problem, but will connect the enables to the common/ground leads instead of EN1 and EN2 on the Acorn.

I currently have the DriveFault coming from the PLC that is looking at the two HLFB signals from the ClearPaths. My Contactor is not being used at the moment.

My setup is to push a start button that the PLC seals in, the PLC has a 20 second time delay that energizes the contactor. In the bottom of the cabinet I have two receptacles that power the Click PS and the Acorn PS. After the 20 second delay the contactor picks up and powers the rest of the receptacles. That puts power to the ClearPath PS, VFD and the fan.

Will keep on testing, makeup the encoder and build mounts for the HomeAll switches.

Did the LED indicators appear to be correct to allow motion?
Thanks,
Chuck

[carbuthn]

Mike,
I left the enables connected to the Acorn (at least for now), but I did get the problem with no movement corrected.

I am using the PLC power supply to power the limit switches, auxiliary power relay and the return leads from the ClearPath servos. The power supply that came with Acorn board powers the Acorn alone. After removing several strands of hair it occurred to me that the commons from the power supply need to be connected. After hooking up a tie wire the tool post could be moved.

I have to check the directions, but it was progress. If I remember correctly I think if the carriage is moving towards the Tailstock that is positive travel, the X axis moves to the front of the lathe.

I still need to make brackets for the Home limit switches, connect the encoder, finish programing and connecting the encoder.

Do calibration and make something.
Thanks to all that helped up to this point,
Chuck

[carbuthn]

I have the Drive direction and calibrations done, but for some reason the soft limit on the X axis is not working correctly.

The X + limit (set at zero) stops the drive in the positive direction at zero indicated and before tripping the mechanical limit switch or the home proximity switch (as it should), but in the negative direction (set at -3.0") it will not stop the X axis before tripping the mechanical limit (set at 3.3").

I have tried different settings. Down powered the Acorn and CNCPC but it doesn't want to work.

The soft limits on the Z axis work as expected and will stop travel before reaching the mechanical LimitAll switches.