Bad Noise from PM 1340 GT

[INTJ]

Whenever I have the leftmost gear level in the "A" position I get the noise in the first video. No noise in any other position.

Also, whenever I run the feed in a "backwards" direction I the noise in the second video. When the feed turns the normal direction I have no issues.

What is up and how do I fix it?

 

[mksj]

Noise doesn't seem to be significant, in particular in the A lever setting which is only used for 4-7 pitch threads, so you would be running around 60-100 RPM. At higher RPM is would generate a lot of noise.

The second noise feeding in reverse, I had something similar to that and it went away as things wore in, but it could also have something to do with the feed clutch. See if there is a noise difference when using the feed rod vs. the lead screw.

The gears come with a lot of packing grease to prevent rust, the grease should be cleaned off the gears and make sure the gears are well lubricated with SAE 68 gear oil or Way oil. There are also some drip holes that lubricate the gears , some of mine were blocked from the packing grease. I ended putting a pump oiler system to lubricate the gears (just built one the other day for another 1340GT owner). I had a friend weld up a drip tray for under the gears, but one could also use a small disposal aluminum pan.

Pm1340gt Gearbox Pump Oiler System

The PM1340GT is very nicely built, works very well, and I have very few bones to pick with its features and overall quality. One area that did concern me when I was revising the front control switches, was the oiler system for the open Norton style gearbox. The current system (which is probably...

www.hobby-machinist.com

Also I had an issue with my gearbox selectors where the engagement pin did not fully engage in the gear alignment hole, you could see the lever walk up and down and rattle a bit in the hole which gave a similar noise. If I put some light hand pressure on the lever the noise and walking stopped. I ended up using a file to trim about 1/16" on the flats shown below which moves the locking pins forward into the alignment holes. This was one of the early 1340GT, so things may have changes. I would only suggest this if the locking pins are not fully seated in the hole and after discussion with QMT.

 

[INTJ]

Thanks Mark! My "A" lever has always walked as well and I really don't need it. It also is quiet at lower rpm. I was only using it for running the apron back and forth after lubing the lead screw and feed shaft and notices the noise.

The other noise is definitely the feed clutch, I just didn't know if it is an issue. When I have the feed direction to the right and run the lathe in reverse (lever up), it clicks. When I have the feed to the left and run the lathe forward (lever down), it also clicks. I just wanted to make sure it wasn't hurting anything.

 

[szenieh]

I just finished putting my quick gearbox back together. When the left lever is in the A, C, or D positions, I get a "knocking" noise much like what you are hearing and the lever "rocks" up and down or tries to "walk" up. I discovered that there is a serious interference between the casting of the lever and the larger gears- i.e., B and D. Unfortunately, I did not take a picture of the interference when I spotted it, but I have pictures and a video showing it cleared away- I had to file an 1/8" to get it cleared. It is rather annoying that this interference is there. I wonder if others have it.

 

[szenieh]

I just finished putting my quick gearbox back together. When the left lever is in the A, C, or D positions, I get a "knocking" noise much like what you are hearing and the lever "rocks" up and down or tries to "walk" up. I discovered that there is a serious interference between the casting of the lever and the larger gears- i.e., B and D. Unfortunately, I did not take a picture of the interference when I spotted it, but I have pictures and a video showing it cleared away- I had to file an 1/8" to get it cleared. It is rather annoying that this interference is there. I wonder if others have it.

Here are some photos-

and a short video after the interference is cleared.

 

[davidpbest]

I had similar issues with mine, and mostly turned out to be the feed clutch shaft and excess filler/paint that had gotten into the indexing holes for the lever selectors and into the bronze bushing on the right side of the Norton gearbox. Part of the problem in my case was a plugged drip oil tube to that bronze bearing, so like Mark I too installed a single-shot oiler system described here.

Your noises sound to me like poorly seating index pins in the first video, and the feed clutch in the second. I'm attaching the process I went through to deal with a frozen clutch feed shaft in the Norton gearbox which might help given you've got the gearbox disassembled.