Possible gear issues with my Jet GHB1340A

T

Tmc3

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Hello all, new member here. I have a Jet GHB1340A that I have had for about 12 years or so. I was boring a bushing the other day. I had the carriage stop set so I would not crash while returning the carriage back to the starting point with the lathe running. I found that if I pushed to hard against the carriage stop I would hear and feel a deep clunking sound. it did not sound like gears grinding or shedding teeth. I continued working, just running the carriage up to the stop gently and did not hear any more unusual noise.

It made me wonder if this was some kind of safety clutch to keep the gorilla from crashing the lathe or if I have something bad going on in the carriage. I have not looked in the carriage gear box yet.

PS I am occasional user of this machine.

Any thoughts or advice will be appreciated.
 
Hello Tmc3!

First welcome to the group!

I cannot speak for your lathe specifically, I will try to dig up a manual later.

I actually hate the term "carriage stop" because it does give the occasional user the idea that the carriage can be power-fed into it.
On the lathes I have used that would cause damage!
The user must disengage the power feed before contact with the "stop" and then hand feed up to it.

Did you do damage?
You might look for stripped gears, damaged half nuts, and even sheared pins.
That last one can be tough to locate as externally everything can look normal and even spin properly, until more force is required to turn the lead screw.

Brian
 
Thanks Brino,

I learned that lesson a few years ago when I let the workpiece get a little close to the chuck under power iI was not watching as close as I should have. It cost me some damage to the cross slide which I was able to repair with a new top slide and gib, the lathe still bear’s the scars.

Fortunately, this time I was hand feeding the carriage to the stop and watching closely. I just pushed a little too hard against the stop when I heard the noise and stopped immediately. The workpiece never came in contact with the chuck, only the small boring bar.
 
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"The workpiece never came in contact with the chuck, only the small boring bar."
? say again?
 
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Sounds like you were feeding your boring bar too far into the bushing and hitting the chuck jaws. Did you check and see if you had any damage to the chuck jaws at the inner diameter you were turning on the bushing? If you were feeding by hand, then the feed mechanism was not engaged, so I can’t see how any of the gears or a safety clutch would come into play.
 
Ischgl99 said:
Sounds like you were feeding your boring bar too far into the bushing and hitting the chuck jaws. Did you check and see if you had any damage to the chuck jaws at the inner diameter you were turning on the bushing? If you were feeding by hand, then the feed mechanism was not engaged, so I can’t see how any of the gears or a safety clutch would come into play.
Click to expand...
It is possible, I did look at the chuck jaws and did not see any damage or signs of contact to them
 
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