Hydraulic 3 jaw chuck removal, draw tube is spinning also

Day shift guy busted a grease zert off on one of the jaws. Well now it has a broken easy out in it. So he decided to take the chuck off to take it apart to have the master jaw on the bench to work on it.

I came in to him not able to get the chuck off and not sure why. So I notice the draw tube is spinning with the center threaded piece of the chuck. The tube is unscrewing from the hydraulic cylinder at the other end.

Anyone have any slick ideas to keep this tube from spinning so I can get this thing off here so I don't have to tear the whole ass end of this thing apart?

The tube is notched for a wrench if I can get the two separated I believe I can tighten the tube back up to the cylinder and be ok. Hopefully!!

Thank you

Brent

Hi Brent,

Usually there is a lockring on the actuator end to prevent the drawtube from unscrewing from it. Sounds like yours has come free. I'd thread the tube back in to the actuator, bolt the chuck back on and unbolt the actuator at the adapter. Then when you unclamp the chuck, the actuator should come off the adapter or should be able to be pulled off the actuator. Then you should be able to tighten the locknut on the drawtube. Then bolt the actuator back on and then remove the chuck. When you put it back together be sure to dial in the actuator. I like to shoot for .0005" TIR.

Hello Kevin,

I remember the old Mori Seki machine did have a locking nut. Looking through the Samchully manual that came with the hydraulic cylinder best I can make out (because it's in Japanese) is it says the tube is supposed to have thread adhesive or Loctite 242 equivalent? WTF?

I'm gonna try to screw it back up the best I can and then see if I can pop it loose? Not sure what to do? Wish I had a way to stop it from spinning.

Brent

yardbird said:

I remember the old Mori Seki machine did have a locking nut. Looking through the Samchully manual that came with the hydraulic cylinder best I can make out (because it's in Japanese) is it says the tube is supposed to have thread adhesive or Loctite 242 equivalent? WTF?

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Hi Brent,

I kind of wondered if some builders might be going away from a locknut to a thread compound. I've not seen that but not surprised.

Taking the actuator off adds to the work, but once it is off you could get a strap wrench on the tube to hold it while to get it loose from the chuck. I'd guess that would be faster than trying to come up with some other way to stop it from unscrewing from the actuator. You need to clean it and loctite it into the actuator anyway.

Have fun!

Kevin

If you don't want to take the actuator off you could take the bolts out of the chuck and spin it off. The draw tube will support the chuck, then slide it out. You could then have room to hold the drawtube while you unthread the chuck.

I have had to cut more than one drawtube to get a chuck off. I don't use thread locker, I use anti-seize on drawtube threads when assembling them.

If you have room, which I doubt unless it's a long bed, you can remove the chuck with the drawtube attached, then work on the assembly on a bench.

Other Brother said:

If you don't want to take the actuator off you could take the bolts out of the chuck and spin it off. The draw tube will support the chuck, then slide it out. You could then have room to hold the drawtube while you unthread the chuck.

I have had to cut more than one drawtube to get a chuck off. I don't use thread locker, I use anti-seize on drawtube threads when assembling them.

If you have room, which I doubt unless it's a long bed, you can remove the chuck with the drawtube attached, then work on the assembly on a bench.

Click to expand...

Looking in the hole from the back end it looks as if the draw tube screws in up to a shoulder. With the chuck on the other end I can't see how it could go anywhere. But that would mean there isn't any adjustment at the cylinder end as far jaw gripping stroke is concerned.

Right now I'm at a standstill waiting on the powers that be to get here to make a judgment call. That's why they pay them the big bucks. Lol..

Really isn't no reason why you couldn't just keep unscrewing the whole thing tube chuck and all to gain some space behind to get something around the tube? That's a good idea!

Thanks

Brent

yardbird said:

Looking in the hole from the back end it looks as if the draw tube screws in up to a shoulder. With the chuck on the other end I can't see how it could go anywhere. But that would mean there isn't any adjustment at the cylinder end as far jaw gripping stroke is concerned.

Right now I'm at a standstill waiting on the powers that be to get here to make a judgment call. That's why they pay them the big bucks. Lol..

Really isn't no reason why you couldn't just keep unscrewing the whole thing tube chuck and all to gain some space behind to get something around the tube? That's a good idea!

Thanks

Brent

Click to expand...

Exactly Brent. The last Samchully actuator I rebuilt didn't have a locknut, it shouldered as you stated. That was on a Daewoo Puma lathe. The drawtube shoulders then you adjust jaw travel at the chuck end, how far on the adapter threads on the drawtube. It should also be close to bottoming out.

I could come help you out, then we could do hip huggers for lunch, lmao!

Best of luck my brother. Daryl

Other Brother said:

Exactly Brent. The last Samchully actuator I rebuilt didn't have a locknut, it shouldered as you stated. That was on a Daewoo Puma lathe. The drawtube shoulders then you adjust jaw travel at the chuck end, how far on the adapter threads on the drawtube. It should also be close to bottoming out.

I could come help you out, then we could do hip huggers for lunch, lmao!

Best of luck my brother. Daryl

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Lol!... I told you if you ever get down here I'm buying.

Nothing better than beer n titties.

Take care Daryl! And Thanks!

Brent