Bridgeport VMC760/20 Z axis not positioning correctly for tool change

[seano_78]

Hi Yesterday we had a blackout in the factory and i was worried that it may have affected the parameters of the machine. I shut the machine down completly until i was sure that we had full 3phase power again! When I turned it back on all seemed to be ok and the machine ran without fault for the rest of the day! At the end of the day i shut it down as per usual and then this morning when i started it up all seemed to be fine, it zero returned and has not thrown up any alarms or errors! It was'nt untill I tried to manually tool change to set up nex job that i noticed that Z height had not gone to correct position to execute the tool change! It was aprox 60mm low and the tool holder forks would have smashed into the side of the head had i not noticed it! Now I am pretty sure that it will be a parameter problem somwhere but am not sure how to go about rectifying this problem! Any help would be greatly appreciated! Also i should add the machine has a Heidenhain tnc 2500b controller

[machintek]

resetting the tool change height procedure (including the parameter)should be in the maintenance manual. I have a classroom book that is at the office that should have this data as well but I have not been there in over a week. Have you tried a cold boot and rehoming it again?

George

[seano_78]

thanx for you reply. i had tried many different ways including a cold start and rehoming but with no success. I'll go through the manual again and hopfully have a bit more success! thanx for the reply!

[CNCRim]

more likely the approximaty switch sensor is worn out or the laser eye sensor is not sensortive anymore...... it need to be replace

[Al_The_Man]

60mm is probabally well out of the axis grid shift parameter, if the tool change position is the zero position of the Z, then it sounds like something shifted on the zero slow down dog for the Z axis.
Al.

[machintek]

Attached, I found a tool change sequence showing relevant parameters, and input/outputs.

George