Hafco AL960-B gear noise

[MOA]

OK so instead of hijacking welder's thread, I thought I'd start my own...
So initially I wanted to see if 0.0015" over the circ of my chuck was excessive, it seems not as the runout follows the chuck, not the spindle. Then I mentioned the noisy gears. I have run the lathe at 900RPM for 20mins and the gearbox temp was just above room temp at a guess. No where near uncomfortable. But while the lathe was running on the High speed gear (960rpm and 1400rpm), it gives off a ringing noise. At low speed (160rpm) it gives a tumbling kind of noise. And at neutral it sounds fine.. I'll try to attach 3 sound files in mp4 to see what you think. I have been under the impression that I need to change the main spindle bearings.
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[Michael G]

If your lathe has straight gears made of steel in the head then they will ring, especially if there is some backlash present. The tumbling noise is probably the same teeth hitting teeth noise but at a lower speed. Not much you can do about it really. A decent thick grease may help if they otherwise run dry. Whether attaching (gluing?) something on the side of the gears to deaden them may kill some of the ringing as well?

It could be bearing noise but I would expect the bearing temperatures to be up if that were the case.

Michael

[Gavin Newman]

If your lathe has straight gears made of steel in the head then they will ring

It does, and they do. My AL960B is noisy on the fast pulley as well. At low revs on the slow pulley I also get the "rumbling" noise. It's been like that since I got it new 5 years or so ago and it doesn't seem to have changed in that time or when the gearbox oil was changed so it seems that this is normal for this model lathe.

If you put your location in your details you may find someone nearby with one of these lathes who might be able to provide an onsite visit to judge the difference in noise, if any.

[.RC.]

Does it make the same noise under load... I have seen stuff grumble away with no load as the gears clash, then under load it goes silent..

Also was the change gear quadrant disengaged? Change gears can be very noisy if not meshed properly..

[MOA]

Ah right. Thanks to you both for the replies. I'll update my profile soon. I'll have to get stuck into it and go through the manual step by step to set it up properly in the coming weeks/months. I've just been making sure it's well oiled and cleaned for the last six or so months. Happy to know the noise is normal :) I'm in Townsville QLD. I'd love to know if anyone up here is doing hobby machine work. Someone with experience on a similar lathe would be a bonus!

Cheers.

[MOA]

Does it make the same noise under load... I have seen stuff grumble away with no load as the gears clash, then under load it goes silent..

Also was the change gear quadrant disengaged? Change gears can be very noisy if not meshed properly..

I've taken some light cuts on some minor jobs as I don't have a coolant pump set up yet, but I didn't notice any change in noise level at those times.
Change gear quadrant not disengaged. I'll have to take another look after work tomorrow to see if that changes any noise output. Thanks for the tip.

[Gavin Newman]

Are you using the power feed, the gears in the quick change gearbox (QCGB) are quite noisy at high speed.

[Ugotdan]

Ok so I've run the lathe with the change gear quadrant disengaged. This is definitely the source of the ringing. It is actually pleasant to hear the lathe operating this way. It seems to be the middle gear making the noise. The same noise occurs wether the power feed or the lead screw engaged. I'll have to make an effort to clean up the gears and set them correctly to see how that goes.
I vaguely recall dampers can be applied to gears to stop noise?? Could this be a viable option do you think??

[Jekyll and Hyde]

Ok so I've run the lathe with the change gear quadrant disengaged. This is definitely the source of the ringing. It is actually pleasant to hear the lathe operating this way. It seems to be the middle gear making the noise. The same noise occurs wether the power feed or the lead screw engaged. I'll have to make an effort to clean up the gears and set them correctly to see how that goes.
I vaguely recall dampers can be applied to gears to stop noise?? Could this be a viable option do you think??



Sent from my iPhone using Tapatalk

Putting a good smear of grease on the teeth of all the gears stopped the ringing on my AL335. Afterwards I replaced the bearings in the big compound gear, which also seemed to help a little... Worth noting also that the mesh shouldn't be too tight, I think some people use a sheet of paper between the gears to get the right amount of mesh - should give you a ballpark idea.

[Gavin Newman]

But by removing the gear-train at the rear of the headstock you've also isolated the QCGB so the noise could possibly still be coming from there. Do you hear the noise with the gear-train in place but without the QCGB engaged?

[MOA]

Sorry about the post from another username. I forgot I even had one when I posted on my phone, I've been lurking a while.
Anyway, I disengaged the QCGB gears and the ringing is still present. It's definitely the middle gear on the change gear quadrant. I'll have to spend some time (between kids and work...) to clean it all up and set it up properly using the manual (literally! :p). Nice bit of kit, I just got to put some effort in.
Thanks for all the help. A lot of great suggestions and tips from you all.

Cheers.

[Gavin Newman]

I use Rocol Open Gear Spray Grease for those change gears and it seems to do a good job and doesn't get thrown around the place like normal grease does. It's a bit hard to find sometimes but a can lasts for ages.