Chuck Unclamp alarm

[esaak]

Hi there,

I'm kinda scrambling right now. On my team, I was mainly the cnc mill, cnc edm, manual lathe, surface grinding guy, and there was this other guy on the team that operated this cnc lathe. Well he retired recently and even though I asked him to teach me, he's basically going to keep his secrets to the grave. Anyways, now the company wants me to learn this cnc lathe asap because we got parts we need to produce with this machine soon. Problem is, I've never touched a cnc lathe before so there's a big learning curve ahead of me. I'm hoping someone can help me.

I'm working with: Okuma Genos L2000-e

The alarm that keeps coming up is: "1741 Alarm-A Chuck Unclamp 1." The manual says: "spindle rotation command is designated (with chuck open)"

I found a post in this forum that had the same alarm problem, which was fixed simply by putting something into the clamp. I tried that, and the alarm is still. I'm guessing I gotta change something in the parameters, but honestly no idea. All I know is that when I want to turn on the spindle with MDI using command m4 s###, or when my program reaches a line that contains m4 or 3, this alarm pops up.

If anyone can help, I will be eternally grateful.

[esaak]

I fixed it! I had to adjust the prox sensors for the chuck clamping. here's the answer for anyone who encounters this problem. found it on reddit:



Take a look at the two prox sensors at the back of the draw tube (there's an access panel you remove if it's still there). Sensor on the left should be lit up for OD clamping, on the right for ID clamping. Only one can be lit at a time- if both are lit it will throw an alarm. There are two allen head screws either side of each prox sensor, loosen them and you can slide them forwards and backwards- slide the ID or OD one into a position where it lights up when the chuck is clamped.

[Algirdas]

the question is if you did it corect. Check if you have "chuck unclamp" when there is no workpiece in the chuck and you command chuck close.
Check this both directions ( there is internal clamping also ).
Means "clamp" is not "close" and "unclamp" is not "open" .. depends on clamping direction OD or ID

[JMxR]

My Okuma Multus U4000 is throwing up the same alarm. So, to fx it i need to adjust both sensors so that only the OD sensor (left) lights up when the chuck is clamped?

[Algirdas]

most likely no. Here in the forum is detailed explanation and it is in the Okuma maintenance manual as well.
Think again. If you adjust the sensor

lights up when the chuck is clamped

how control suppose to detect the lost workpiece?
Check with the manual. Here I will tell the general rules:
1. Make sure you have maximum draw tube travel.
2. Install juck jaws and make sure have maximum draw tube travel.
3. Adjust the LS sensors at the ends of the travel.
How it works:
1. Unclamped is indicated by limit sensor at corresponding end.
2. Clamped is detected when no limit switch activated and the hydraulic pressure is applied.
3. If the workpiece jumped out of the chuck, the draw tube will travel a litlle bit more to clamping direction and reaches the corresponding limit switch. The workpiece lost is detected
The same story with OD and ID clamping.