Triac VMC Homing Problems

[cdmodelz]

I am running a Triac VMC. It refuses to home. I have taken the various covers to get access to the home/ref switches and none of them are sticking. It may be a faulty cable.

Does anyone have any suggestions as to fixing this as I cant run the machine without homing as it has an 8 station tool changer. I dont know how it is even possible to replace the switches as there is no way to access the cables without taking the entire machine apart and there is no way of opening the Burgess switches to gain access to the wiring.

Any help would be greatly appreciated as I am at my wits end as of now with the machine. Leaky air cylinders on the TC have just been replaced so the machine was down for days doing that and now dead home switch. The machine has done very little work and only cut plastics so I am really not sure why they would go. I could understand if they were soaked with coolant but they are dry and in good condition.

[Martin]

Are the stepper motors powered up? (Try to turn the X axis ballscrew by hand).

Have you tried the "Axis Limit Overide Switch" (Press & hold whikle homing machine).

[Denford Admin]

It refuses to home.

Do you mean the axes move but don't 'see' the switches ?
Do they move slowly in the wrong direction ?
Which axes - all or just one ?
Do they not move to home at all ?

[cdmodelz]

One of the 3 switches or one of the cables going to the switch is faulty. I am a bit puzzled on how to change the switches or cables as the access is limited to the cables which run through the casting (have to take the machine apart to get access). How do I change the switches?

Could anyone advise on the process of replacing home switches or cables attached to home switches

[Martin]

Can you be specific?

There will be 3 x home proximity sensors. X, Y, Z.

Can you home any of the axis?

[cdmodelz]

Hi. Unfortunately I cannot home any of the axes. I have checked the sensors with a meter and they are all OK. Only other thing it can be is one of the cables from the main box to the sensors.

If I need to change a cable is there any info on how to go about it?

[Martin]

Do the stepper motors power up?

[Steve]

What happens when you try to home? do the axes actually move? If not then its nothing to do with the home switches!

I think you need to see if the axis drives are enabled.

There have been several questions as to what happens when you send the machine home that you have not answered.

If the axes are not trying to move and go home then the problem is not a home switch

[cdmodelz]

Hi. Thanks for the reply. The axes do not move when I press to home the machine.The problem could be a home switch or a cable. I am still trying to diagnose which switch or cable is faulty

[Martin]

Is the emergency stop relay is energized? (Check if the red power LED is illuminated on the Sprint 1200 drive.If it is then the E-Stop line is OK).

Check that the air pressure is sufficient. (80-100psi)(The air pressure switch will be in the E_Stop lime).

Check the fuses which are on the top of the backplane attached to the rack. (There should be 3).

If there is a fault in any limit switch pressing & holding in the Axis Limit Overide Switch should allow you to power up the drives but you will need to keep it pressed in until you have correctly homed the axis.

[cdmodelz]

Problem has been fixed. Z lower limit switch contacts were fused together, making the circuit N/O. Removed the switch and reworked. All ok now