1340GT Feed Clutch Slipping

parshal

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I oiled all ball oilers, the quick change box and changed the headstock oil. I run the lathe to get the oil moving around to check my fill level and find the feed clutch slipping. It was working fine when I turned it off yesterday. The oil fill(s) were the only change. I see nothing unusual in change box when I remove the cover. The tailstock side of the feed rods have been regularly oiled so I can't see it being seized.

See video.
 

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  • feed_clutch.mov
    15.7 MB
Turns out the feed shaft is now seized behind the apron. I removed the support block from the tailstock side and can slide the shaft in the back of the apron. I'm guessing the gearing that engages is seized. Now, I'm guessing I have to remove the apron to get to that part to check it out.

Anybody had to do that before? Any advice? I've done it on a SB10K but not this lathe.
 
Well, now that I'm this far I might as well start sharing pictures if people are wondering what the insides of their lathe looks like.

I took the apron off in an effort to see how it works and what's binding the feed rod. The power feed will not move now. I had to step away from it for work but I need to figure out why the lever is not moving the gear. I can't move the gear by hand. Nothing looks broken or galled.

aprongears1.jpg


aprongears2.jpg


aprongears3.jpg
 
You might want to have look my post which is more about the power feed driveline on a somewhat similar Taiwan 14x40 lathe. There is also some discussion on the clutch mechanism which, as it turns out, was kind of the early warning of underlying problem. You might see some similarities or you might have different issues but hopefully you will get some more insight into the beast.
https://www.hobby-machinist.com/threads/14x40-lathe-power-feed-improvement.64907/
 
Turns out the feed shaft is now seized behind the apron. I removed the support block from the tailstock side and can slide the shaft in the back of the apron. I'm guessing the gearing that engages is seized. Now, I'm guessing I have to remove the apron to get to that part to check it out.

Anybody had to do that before? Any advice? I've done it on a SB10K but not this lathe.

Not as bad as you describe but my PM1340GT carriage feed has become progressively more difficult to engage. Please continue to post your findings, I may be in this same boat soon!
 
I got the feed shaft off the apron. I was eventually able to turn the shaft by hand once I was to this point. Missing in the pictures is the bronze gear installed that meshes with the threaded bearing. The only thing I can find anywhere is the mark on the third thread down shown in the second picture. It's raised just enough that the bearing didn't easily slide out of the housing. I had to tap it with that large brass punch. I filed it down and now it easily slides in the apron housing. I can see brighter markings on the gear but I can't tell if it's from this ding on the threaded bearing or just wear marks. The lathe has well less than 10 hours of total use.

I gambled and reassembled the entire machine and it now works. That little bit of raised metal on the threads was enough to cause the feed clutch to disengage. Amazing.

Sending the pics to QMT to see if they can replace this and the bronze gear.

Notes for next time.

  • There's a threaded "keeper" on the back top of the apron that puts pressure on the feed lever indents. If you back that off make sure to put it back so you don't have to pull the re-installed apron off again.
  • To make it easier to get the feed lever in the corrects spot rotate the housing so the lever doesn't hit the threading lever when you rotate it in place. Make sure to do this before you put the apron on so you don't have to remove it again. Sensing a pattern here?
  • Two people installing the apron would be a big help. It's heavier than you think and you have keep all three rods aligned in the tailstock housing.
  • Back the screws off the feed clutch and use grease on the ball bearing to hold it in place when you install the feed rod. Once under power, use the jog to move the gear where the notches line up with ball bearings. Then tighten the screws. It's amazing how little pressure they need to engage that clutch. Oh, and don't lose the spring and ball bearings when you remove that clutch.
  • When you remove the power lever from the apron oil will come out the hole closest to you. Make sure you're ready to put the screw back in to keep your oil. Or, just drain it there. I ended up turning the apron over a car oil drain. It would have been cleaner to simply drain it the screw that came off.
  • It'd also have been smart to add apron oil before I re-installed it. Now I've got to use that front fill hole.
  • I also noticed on both the headstock and apron oil level indicators that they don't drain oil. I have no oil in the apron and it looks full.

feedworm.jpg


feedworm1.jpg


feedbronzegear.jpg
 
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The sight glass is probably more of an illusion. Once oil has reached the lower ports in the sight glass the bubble will fill and you ll see the proper level. Take note of what s going in.
 
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