Random teknic Clearpath Z axis Brake Failure when homing

[TheKitMill]

Drive powers up normally when jogged brake release and z axis moves. But when Homing is started it randomly fails and drops hitting reset twice enables the drive and it can then be homed. The drive will also lose control of the z axis randomly when a cycle start is commanded at the beginning of a program



After Z axis fail the z can be reset and homed the machine can then execute a complete program with no issues. The z axis Brake failure usually happens during the homing of the machine. But it has randomly happened when pressing cycle start to execute a program

CNC4PC Boards and Clear path motors and Drives.

[cnckeith]

how is the brake being activated/deactivated?

unrelated question, is there no reduction from the X and Y axis motors to the rack pinion? .5 turns per inch will not yield great machine motion results.

[Gary Campbell]

Are you performing actions that require the brake to be cycled on/off during machining? If not and you are simply looking to prevent Z drop during off times, you can energize the brake with the OkFault output or connect it to the 24v power to come on with the system

[TheKitMill]

Thanks all for taking a look. The brake is released vis z axis brake release on out put 3. This Z axis drop is random Sometimes I power up home normally and then run a program and all is well. But the error can be made to happen after a power down after a change has been made to the Wizard. On drive reset pressing the cycle start key can and usually causes the z to drop like a rock but hitting reset twice enable the drive and it moves as it should. This was operating with no problems with out random z axis drop.

Ratio is 4 to one reduction. Don't know why .5 works I will check the tuning software after i get the z axis random drop solved.

But it does run a complete program with no fails or errors once I get it homed.

[TheKitMill]

Machine running simulating tool change cycle. The random Z axis drop just started happening.

[TheKitMill]

Are you performing actions that require the brake to be cycled on/off during machining? If not and you are simply looking to prevent Z drop during off times, you can energize the brake with the OkFault output or connect it to the 24v power to come on with the system

Hi Gary

thanks for taking a look

Just trying to get the z to stop dropping randomly . It appears to happen when the Cycle start key is pressed built not always. For example I open the wizard. Change the turns ratio then close cnc 12 with a power restart the machine is still homed but sometimes if I try to jog z it drops like a rock If it has been homed I have to power down re-start the drives and re home. If it drops before a homing I can hit reset twice and it will then allow me to jog the z. and home it. Right now I am simple home until I solve the random drop problem

I am using no fault out to enable the drives with the CC4PC board and axis brake release on output 3 . It appears that randomly the z axis motor gets deenergized while the break is energized so it drops. But I can always get it going by hitting reset twice hitting in once does not work.

Tried both hard and soft enable with the cnc4pc board same result. So not sure if its a drive, motor,cable of cnc4pc board problem.

[TheKitMill]

https://youtube.com/shorts/MSnauabVGBs

Machine running tool change simulation

[TheKitMill]

here is a picture of the Panel and how it is wired.

there is a on off switch wired behind the disconnect press on Button it powers up the Acorn Board and second 23 V power supply. Turn on cnc 12 hit reset to enable the drives and VFD home machine and go. All work well except for random z axis drop.

[cnckeith]

I'd swap out the cnc4pc board as a process of elimination test.

[TheKitMill]

Hi Keith. I think that a good idea i just order one as well as a new set of cables. If it did it every time i would blame my wiring but its random and once homed runs a program with no errors. I am still working on the steps per inch problem. It also seems like there is a lag between the Clear Path drives taking control of the motors and the brake release. But in any event the z should never drop like this once the drives are enabled. Also it appears to be isolated the the z axis. After the drop the z axis motor is not green until reset is hit twice. But x and y motors are fine. I can still jog x and y even after a z axis failure. The will post an update after i swap out the board and replace the cable for the z axis