PM1030 Change Gear Adjustment (noisy)

[r-mm]

Hi all

I'm noticing a decent amount of noise from the change gears. There seem to be two issues - one is backlash which I don't see an easy fix for. The other is the somewhat odd means of taking up thrust / end play. To the best of my interpretation there is a thick plain washer bearing on a non machined surface of the gear. The only realistic option I see here is to leave the assembly loose resulting in a decent amount of end play. Since the plain washer does not appear to be an oillite or other bearing material it predictably makes noise when snugged against the gear. I was going to modify this with a ball bearing and wave washers. Anyone else encounter this?

Thanks

 

[Jim F]

I have some wobble on the idler on my SB9, it is not an issue.
The backlash adjustment is set with a piece of paper between the gear teeth.

 

[KevinM]

I have a 1022 (same headstock as yours) that howls like a uh, uh, uh, howler monkey when I set the gears too tight. You need to experiment with backlash. From your picture it looks way too tight. I remove the cover safety prong and plug it in so that I can test without removing the cover 10 times, you should not do that because it is unsafe . My lathe needs quite a bit of backlash to run quietly. The gears will also need to wear in a little bit.

 

[Jim F]

I have a 1022 (same headstock as yours) that howls like a uh, uh, uh, howler monkey when I set the gears too tight. You need to experiment with backlash. From your picture it looks way too tight. I remove the cover safety prong and plug it in so that I can test without removing the cover 10 times, you should not do that because it is unsafe . My lathe needs quite a bit of backlash to run quietly. The gears will also need to wear in a little bit.

Not if correctly set.

 

[r-mm]

I will loosen all the T-nuts and the primary gear carrier and have a go at adjusting backlash for all of them. The lathe is new to me but not new so the gears have already worn in to each other.

 

[markba633csi]

Straight cut spur gears are inherently noisy by their nature, but anything causing excess friction or uneven running should be dealt with
I think installing ball thrust bearings might be overkill since most lathes do fine without it
-Mark

 

[Weldingrod1]

Tightening the nut should NOT tighten the washers against the gears. You want that stack to lock up solid with the gear free to spin. You may want to fab up an integral washer-sleeve bit that has the right length. Or, buy a shouldered oilite bushing and trim to length.
You need the stack locked so you can set the gear positions right and have them stay put.
My Hardinge has externally keyed sleeves that the gears go on that, in turn, spin on a shouldered bushing.

Sent from my SM-G892A using Tapatalk

 

[r-mm]

Understood. But the way the machine is designed tightening the 'special nut' does in fact tighten the plain washer to the face of the gear. I am stating that as my experience and asking it as a question to be sure I understand the machine correctly.

 

[markba633csi]

You probably need to modify the design in that area, agree with weldingrod in post #7
Shoulder bushings slightly longer than the gear width are the standard approach
-M

 

[KVan]

Unsure if you are aware, the "Adjustment nut" that you are holding stays on the shaft once it is all tuned. When you change gears you remove the entire shaft to swap gears out.