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Turret Crash from boring bar stickout

clayton

Aluminum
Joined
Aug 19, 2011
Location
Houston Texas
Okuma cadet LNC-8 94 model I believe

Setup a boring bar and it was sticking out too far from the backside of the turret. Upon tool charge it crashed into the base of the turret.

Now it's sticky with tool changes and the turret won't completely rotate on it's own.

What should I look for when fixing this?

Thank you
 
Okuma cadet LNC-8 94 model I believe

Setup a boring bar and it was sticking out too far from the backside of the turret. Upon tool charge it crashed into the base of the turret.

Now it's sticky with tool changes and the turret won't completely rotate on it's own.

What should I look for when fixing this?

Thank you

You probably need to remove the face cover,loosen up the bolts and re-align the turret.
It's most likely off rotation. There are usually tapered dowels you can put in there to easily realign it.
Once you know how to do it, it's relatively quick and painless.
 
I actually did that, it's still has the issue. The pins were in a little bit of a bind. But got them removed. I know two other shops with okumas that said they had to do the same as you mentioned. It didn't resolve my issue. I can't possibly imagine it doing that much damage when a bore bar hits the casting on a tool change.
 
I jumped back on this issue to try to resolve it. I removed the turret, and removed the two pins with no issue that go through the clutch plate. When the E-Stop is on, the hub that drives the turret has a little slack when rotated by hand. But not when under hydraulic pressure. By looking at the parts diagram there is another tapered pin on the back side of the complete assembly.

I was thinking the tool change looked kinda sticky, and when I pulled the turret off, it sure was consumed with a ton of rust all over. But when I did a tool change with no turret on, it still would have issues sucking back and locating.

Does this bring any new suggestions to look into? Next thing when I have two people at the machine, I will check the turret pressure on the gauge on the back under a tool change.


all-tappered-pins.jpg
back-of-turret.jpg
okuma-cadet-turret.jpg
 
The turret should be all hydraulic. So, a piston pushes the shaft out and pulls it in to unclamp and clamp the turret. Then a hydraulic indexing motor rotates the shaft to index the turret. The indexing motor has a shot pin to stop it at the same place each time. The motor is typically geared or belted to the turret shaft at a ratio equal to the number of tool stations. So, if you have a 10 station turret, the motor is geared 1:10. That way each time the indexing motor makes one revolution and hits the internal shot pin, it has moved the turret one tool station.

There should be two solenoid valves and two flow control valves for the turret. There may also be some sequencing valves and other things. Try to find them. They may be on the turret or on the back of the machine near the hydraulic pump.

You should be able to manually actuate the solenoid valves by pushing on the ends of the spool. The solenoid will have a metal or plastic cap on the ends. If you push in the very center with a pen or small punch, you can manually move the spool in the solenoid and manually actuate the hydraulics.

Your machine is pushing the turret out OK, but not letting it come back. There could be an issue with the flow control, the solenoid, or the actual piston and shaft that are moving. I would manually actuate the solenoid and see if it works differently than when the control actuates it automatically.

The control is waiting for the piston to pull in and make the switch. If it does not happen in the time limit set in the ladder, the machine will alarm out.
 
It did alarm out with that error only after I had pulled everything apart. Never before when the turret was still installed. Which is kind of weird. But I'll be checking those solenoid manually and see if there is any difference. I don't see how this would come about from such a common rookie mistake!
 
What do you mean when you say it will not completely rotate on its own?

It's possible that you messed up the timing/indexing between the turret and rotating part of the curvic and the wheels that actuate the switches in the back. If that has happened, the turret will rotate around and stop, but it can't pull in all the way because the teeth of the curvic are no in mesh.

Some machines are pinned or splined so that can't really happen. Others use tapers or slip couplings that can be shifted.
 
Before this video, the turret would stop more often than not, and slow down in the area that it would stop upon a tool change. It also seemed to be more consistent with not functioning when in manual mode and just spinning the turret. When you would MDI a tool change command, it seemed to complete the change more often, but still suck back really slow. Prior to the crash, it never had any issues what so ever.
 
Watching your video there is either damage to the internal piston or there is something wrong with your hydraulics, either improperly set or solenoid not opening completely etc. The system is simple it's a basic hydraulic piston, pressure on one side then switch and pressure on the other and since you have the turret off there is no curvic to line up. You have more to take apart but I would check your pressure first.
 








 
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