The noise may be caused by incorrect meshing of the gears. Too little backlash will cause noise and premature wear. Too much backlash will cause noise and an inconsistent feed rate.

The gears should be meshed with a piece of card or paper between them, about 0.003" (0.075 mm ) thick to set the correct amount of backlash.  Obviously, remove once the meshing has been set.

You must expect some noise. Even precision ground gears emit some noise.

Heavy grease will reduce noise, but as you say, should be kept away from belts and pulleys.

The gears on your lathe are unlikely to be as precisely manufactured as those in your car gearbox, and they make some noise.

Howard

Edited By Howard Lewis on 22/08/2020 12:22:20

Um, metal change gears are noisy so could be normal.

However, the amount of meshing between teeth can make a big difference. I set each gear apart on the banjo with strip of thick paper (or a strip of ordinary A4 printer paper doubled over). Setting the gears too close makes grinding noises and having them too far apart causes banging and rattling. A mixture of too close and too far apart on the same train is the worst combination. Too close can cause problems if a pair of gears aren't quite circular because they can cam together at certain points, adding to the racket and stressing the teeth. Experiment with different thicknesses of paper.

Change gears aren't precision, nor are they ground to reduce whine at high speeds like a car gearbox. Functional rather than ear-friendly. Plastic gears are much quieter.

Dave

As well as correct meshing close attention should be paid to the washers that fit between banjo and gear as they are different thicknesses, if you get them wrong the sides of the gears can rub giving a ringing sound. Thin washer should go against a large gear and thick washer against a small one.

I find it easiest to adjust the gears on the banjo first starting by the last gear on the train. Using the paper method is good but too fiddly so I just make sure there is some backlash by eye and feel, you will soon get used to it after spending some time on it. As Jason mentioned above pay attention to the side clearance as well, apart from the washers, moving the banjo in and out will also effect this clearance.

My modified Kaimac 180 lathe feed geatrain makes to much noise when feeding 0.083mm at 1000 rpm,but is not objectionable when thread-cutting at 60-90 rpm.

I would like to have finer feed for most jobs and I do not like the lubrication monkey buisness for first gear contact and the special stud that have been nessecary.

I is maybe worth asking You engraving for a quote on a solid say 76/20 compound gear in Delrin running on a special 12mm stud.

Not a lot lubrication close to belt and noise very much lower

What not to like?

Edited By Niels Abildgaard on 22/10/2020 16:39:23

You Engraving is Nom du Guere for a gentleman that offers very reasonable ,well made gears to order via E-Bay.

I think I recommended him to Bernard two months ago and gave a link that was confiscated by our never sleeping guardians of good conduct.

A little winded

Edited By Niels Abildgaard on 22/10/2020 17:44:39

Oh for gods sake this is ridiculous!, how come an Ebay supplier selling decent products is 'verboten' I'm thinking of getting a Delrin gear but have to trawl the net to find said supplier?

Tony

Found him

Edited By Tony Pratt 1 on 22/10/2020 18:10:52

Please excuse my bad memory.

ME had not confiscated a link to You Engraving

It must have been something else.

Bernard :How did You unite the 20 teeth Module One Delrin gear with the 80?

The normal Bush/Key system is 12mm dia and key protudes 1.5mm that leaves ca 1.4 mm Delrin between key and bottom of tooth-gap.Has it stood test of time?

Edited By Niels Abildgaard on 24/10/2020 16:16:51

Edited By Niels Abildgaard on 24/10/2020 16:18:15

.

But Bernard wrote [in this thread] :

as advised contacted You- Engraving .com.

… which is what I was querying

MichaelG.