Problems with Jet GHB-1236 metal lathe

A

akoldnav49

Registered
Registered
Joined
Aug 8, 2019
Messages
7
This lathe was bought new by me 2 years ago and has very little use. Suddenly the power feed will not engage. I can feed manually and the threading system works normally. I, after a long day finally got the top off the apron gear box but I don't see anything that I recognize as broken or out of place. Is there an actual shop manual for these or at least something besides the small operation and maintenance book that came with the lathe? Secondly has anybody here had the same problem and maybe steer me in the correct direction. I live in Anchorage and there is nobody that works on these left up here. HELP and thanks in advance.
 
I don't have that lathe. Sometimes on my lathe the lever for the half nut engagement prevents the carriage from being engaged. Try lifting the half nut lever and engage the carriage at the same time. Maybe the detents on the levers are off a hair? I think that's the problem with mine?
Cheers
Martin
 
^^ This ^^ There's a lever that drops into a slot to prevent engaging the lead screw and feed rod at the same time. Lift up on the half nut lever!
 
I have a similar lathe that is about 40 years old and the only time I had problems with the power feed a simple top off with ISO-68 oil got it going again.

Is the feed rod turning? Not saying you made this error, but I’ve actually seen people forget to switch the machine from lead-screw to feed rod. Only one can be engaged at a time.

Chris
 
Shadowdog500 said:
I have a similar lathe that is about 40 years old and the only time I had problems with the power feed a simple top off with ISO-68 oil got it going again.

Is the feed rod turning? Not saying you made this error, but I’ve actually seen people forget to switch the machine from lead-screw to feed rod. Only one can be engaged at a time.

Chris
Click to expand...
Yes the feed rod is turning, but I have discovered another problem related in the gearbox. The dials run 1 thru 5 on one dial and a thru e on another dial. The gears will only turn about 3/4 of a turn when shifted into 2 thru 5, but works properly when in position 1. I am going to send the gearbox module and the apron module to Uniwest in Illinois. I have taken them off and am now making shipping crated. It is hard to securely ship heavy items from Anchorage to Illinois so I am making wood crates.
 
Before you ship it off, have you removed the front of the gear box? Pulling the shifter knobs and the ID plate should expose the fasteners to open it up. (Don't lose the detent balls and springs in the knobs) I replaced all of the bearings in my BDB-1340 and it's fairly intuitive once your in there. The only tricky part about the job is reinstalling the shift forks and even thats not bad. Are they covering this under warranty?
 
You need more posts in order to post pictures so, keep asking questions! The apron is easy to diagnose as well. Was there a crash just before this problem started?
 
Here's an online manual, page 24 shows the gear box breakdown. It looks like you don't even need to remove the knobs, just the data plate. It sounds like the the gears are only meshing when shifted to a hard stop (#1), look for the problem.

Check the setscrews that hold the shifter knobs on the shift fork, might not be shifting. When you do shift, shift for engagement not what the indicator shows. Open the box and shift by hand while rotating the input shaft. Look for obstructions or anything loose.

POST what you find!

 
You must log in or register to reply here.
Back
Top