LNC8 (mid '90's) weird chuck unclamp action

[Voss_Machine]

So I've had this machine since it was new. I run some short run production using bar stock material...without a bar feeder.

Using this code;
....
M5M9
G0Z.005
X-3.4
M84 (SET PART)
M00
G0X20Z20
M2

At the M84 I slide the bar manually to a stop and close the collet using the foot pedal....however, the M84 has become lazy....and even stranger to me, maybe just coincidence, but when I open the door then the M84 will complete. But if I don't open the door, it may take 2-3 seconds for the M84 to complete. System pressure is good, chucking pressure is ~200, the proximity sensors on the drawtube are set good.....and it runs fine at start-up but as the day progress' get to this issue.

Using the foot pedal doesn't open the collet any quicker either.

Thoughts?

Similar Threads:

• LNC8 (94) control shutting off mid program
• Need Help!- Chuck clamp/unclamp confirm
• Need Help!- Chuck clamp/unclamp
• Need Help!- 1006 SP#1 CHUCK UNCLAMP ALARM
• M-code for Chuck Clamp/Unclamp

[OkumaWiz]

Has anyone turned the key from hydraulic to air chuck? That just uses a 5 second timer… the hydraulic also has a timer…has that been changed?

Best regards,

[Voss_Machine]

Has anyone turned the key from hydraulic to air chuck? That just uses a 5 second timer… the hydraulic also has a timer…has that been changed?

Best regards,

I'm the only person that runs it. When it delays, I can get it to open as soon as I move the door interlock switch..not the key, the switch.

[OkumaWiz]

If you check the EC input for the chuck prox switch is it occurring immediately or after the 2-3 seconds? The prox switch feedback should happen immediately so if it’s not then try changing from OD to ID chucking just to see if confirmation occurs quickly when using the opposite prox switch. If the delay changes you may have a prox switch going bad.

If it doesn’t come on in the EC input table until after the 2-3 seconds, I would suspect a solenoid but I think you could tell if the solenoid was activated by listening to the sound and watching the chuck motion.

Best regards,

[Voss_Machine]

If you check the EC input for the chuck prox switch is it occurring immediately or after the 2-3 seconds? The prox switch feedback should happen immediately so if it’s not then try changing from OD to ID chucking just to see if confirmation occurs quickly when using the opposite prox switch. If the delay changes you may have a prox switch going bad.

If it doesn’t come on in the EC input table until after the 2-3 seconds, I would suspect a solenoid but I think you could tell if the solenoid was activated by listening to the sound and watching the chuck motion.

Best regards,

My first thought was the chuck solenoid, but I think I've ruled that out as moving the door switch allows the collet (chuck) to actuate. The "clamp/unclamp" status LED changes immediately, yet the drawtube never moves. I think it's one of the relays on the RU1 board. I have them coming and will get them replaced and see where it leads me.

I would change it from ID to OD clamping but I have a job in there right now.

Thanks so much for your thoughtful reply!

[Voss_Machine]

I must have either swapped out the wrong relays or something else is gong on. I swapped out the 6pcs of RI-D25M....and nothing changed. I think I need to research the wiring diagram a little better.

[Voss_Machine]

Just to bring closure to the thread.

I replaced the CH1A, CH1B, CH2A and CH2B relays on the RU1 board. Works like it supposed to again. Which one was actually bad? Good question, but they all have something to do with the chuck clamp/chuck unclamp circuit.