Laser 4000 Overlength Front fault

[Jim H.]

I would appreciate your opinions on an intermitent problem. I have a Laser 4000 that is 10 years old. The machine has been retrofited with a Virtual Treadle that uses photo eyes mounted on either side of the bay and this bay is short. The set of eyes toward the exit side (I believe they send the signal to back up) of the bay are within inches of being blocked by the T-bar when the machine is in home position. I recently bought this wash so the problem could have been happening for years. I am receiving an overlength front fault at the beginning of the wash cycle. I have tried a few things thus far.
1. Replaced front eyes
2. Adjusted amp in the jo3 box(one amp with two relays on either side)
3. Swithched relays to see if the problem moved (it did not)
4. Replaced prox. switch that reads front limit
5. Replaced front flag
6. Adjusted one of the T bars about a 1/4 in to make it plumb
7. Changed out x21 wire in festoon with one of the spares
8. Tested the voltage at relays with output y40 on

When the problem occurs, it happens regularly until I move the bridge from the home position and back. I may have made some mistakes with my tests so please don't rule out any of the above out. Thanks for any advice on this problem.

 

[madscientist]

you probably just need to change your shear bolt (in the arch). when the bolt wears down, the bottom arch sticks out a little and blocks the exit side t-bar eyes at start up. "overlength front" has nothing to do with the vt, it's the exit side t-bar eyes.

 

[Jim H.]

Thanks, I will try switching the shear bolt. I hope it is that simple, I should have posted this thread a few weeks ago.