Noisy Gears on my PM-1236T

[Just for fun]

After a switched over to the ELS system, I set the gear selectors at D and 6. They seem to be somewhat noisy compared to the to where I normally had them set. Anyway, I thought I would open things up and see what things look like. I decided to put a little grease on the gears just for the heck of it and see if it made things better. I do add oil every time I use the lathe, but to my surprise the grease made a huge difference in the noise. I'm not sure how long it will last but it sure helped.

 

[Ulma Doctor]

As gears wear , the backlash increases, increasing the noise of the gears in mesh.
The grease is taking up backlash until it is pushed out
You can’t really adjust the backlash on the QCGB , so the noise will continue to increase

 

[mksj]

Just be aware that the oil also lubricates the bearings and shafts, the grease is only the gears. You might consider a pump oiler system, I would do 2-3 pumps whenever I started using the lathe gearbox. I also like to use Vacuoline 1409 or similar oil with tachifiers so the oil would be more likely to stick to the gears. I assume to some degree you might be able to use both. On the change gears I used impact grease which would not fly off the gears, made it much quieter under the belt cover, but not an issue here..

 

[rabler]

Just wondering if you could be getting some stepping noise in the gear train, as stepper motors "pulse" the torque especially at lower RPM. One test you might try is turning the current limit down temporarily on the stepper driver to see if it makes a difference.

 

[Just for fun]

Randal, That very well could be what going on. It's not bad but it's more then I think there should be. I took the cover off to check things out, I don't see anything wrong, but the gears are looser than what I remember in a truck transmission.

The noise is kind a raddling sound if you will. It's more pronounced when I turn the feed rate up, or I think when I have it set for low number of TPI (I need to check that again to make sure that's when it happens).

Before the ELS: Being that I'm still learning, I haven't really moved the feed rate much off of the slower settings. I've cut a few different thread counts, nothing below 11 tpi.

After the ELS: I have played with different setting, feed rates, TPI changes and that's when I really noticed the gear noise. On the ELS setup I'm using gear selection D and 6 and I'm not sure I have had the lathe in that position before. So, I thought maybe something was up with those gears.

After looking things over I don't believe there is a problem, I think it is just the looseness / backlash in the gear train, and I think you are probably on to what is causing it to make noise.

 

[Mr Mike]

My understanding is the 1236T doesn't have hardened gears, when I asked about that I was told it would be a none issue in a hobby use setting. lol I don't even have my 1236T set up yet - Its still in the crate, guess now would be a good time to ask if I can order a spare set of gears just in case...

Hope all is ok with your lathe and its just the stepper motor causing some extra chatter, Fingers Crossed for ya.