Noisey Gears?

[Martyn Nutland 1Participant @martynnutland1]

Hello

I have a new Proxxon PD400 mini lathe. There is a certain amount of noise from the gearbox and I wondered if other folk with this model had experienced that? I took care meshing the gears and have left just a slight amount of backlash. I’m wondering if I’d be better with none.

I spoke to Proxxon customer service who were very helpful. They said not to worry about some noise from the gear trains.

My other lathe is a Chester Super B and that does, and has always, run virtually silently. But then it drives by belts and pulleys whereas the Proxxon has gears. Maybe that’s it? Any reassurance would be much appreciated.

Happy Easter All   Martyn

[John HaineParticipant @johnhaine32865]

Gears make noise alas.

[DC31kParticipant @dc31k]

The phrase “noise from the gearbox” does not sit well with “took care meshing the gears”. I am not aware of many gearboxes where the mesh is adjustable. I suspect you mean the change gears.

If so, an option might be to replace one or more with tufnol or delrin items, so there is less metal-to-metal contact.

On a European-made machine, the gears will likely be a standard module, so the pointy part on the outside would be off the shelf, leaving you only to puzzle over the middle bit.

If you rarely cut threads and generally use just one ratio between spindle and leadscrew, timing pulleys and a belt are another option.

If they are noisy at high speed, and you only want to drive the leadscrew for a fine feed, a supplementary motor driving the leadscrew (possibleyfrom the tailstock end) could also be an option, then the spindle does not need to be connected to anything.

[bernard towersParticipant @bernardtowers37738]

If the  gears are set up with paper spacers and a LITTLE Ep oil added and they still make a noise then I would say its down to gear quality IMHO.

[halfnutParticipant @halfnut]

Did you put a strip of paper between the gears to set the backlash, then check it at several points around the full circumference of the gear for tight spots?

Not a lot else you can do really. Gears will be noisier than belts. And steel gears noisier than cast iron, due to ” ringing”.

Plastic or fibre gears would be quieter but not as strong. Might only need one gear at the spindle end of the train to be plastic or fibre to quieten it down.

[DiogenesParticipant @diogenes]

If it’s brand new it’ll almost certainly get quieter as you run it in – new gears are always noisy and the machine won’t have had anything but the briefest running (if that) before being sent out.

I’d be very surprised if the full train is metal.

[Michael GilliganParticipant @michaelgilligan61133]

There are several reviews of the Proxxon PD400 mini lathe on YouTube

… it would be worth skimming through them.

MichaelG.

[Graham MeekParticipant @grahammeek88282]

I apply a Moly based grease made by Rocol with a small artist paint brush on my Emco Compact 5 quadrant gears. I also set the gears with a strip of paper to ensure a constant clearance. Rolling the paper between the gears and then locking the adjustment. The paper strips need to be the same or slightly less than the width of the gear.

While there is the additional noise from the gears in my screw cutting clutch attachment, as well as the standard gear train, this is still a quiet lathe.

Regards

Gray,

[halfnut]

On halfnut Said:

Might only need one gear at the spindle end of the train to be plastic or fibre to quieten it down.

Putting it at the end of the train will only quieten the noise betweeen it and the one above. Putting a non-metallic one in the middle of a train is twice the noise-reduction for the same price.

[old martParticipant @oldmart]

You could try a squirt of motorcycle chain grease, anything fairly thick should help. And try increasing the looseness of the meshing, I find that tight meshing makes the most noise.

[Howard LewisParticipant @howardlewis46836]

Each mesh should be set by running a sheet of paper (About 80 gm is good) through it as it is set set up

I always start with the Leadscrew / Idler mesh, and then swing the banjo to set the Idler/Driver mesh

With a little grease, or thick gear lubricant, the noise level is acceptable.

Meshing too tightly, will cause noise and wear.

Howard

[old mart]

On old mart Said:

You could try a squirt of motorcycle chain grease, anything fairly thick should help. And try increasing the looseness of the meshing, I find that tight meshing makes the most noise.

Despite some folks’ recommendations for only using oil, providing the gears are in a reasonable dust free enclosure, I use the same.
Note the comment about aerosol grease as opposed to motorcycle chain wax; both are different to normal lithium bearing grease.
You might even find that a commercial chain lubricant is cheaper; I’m still using a supply I bought designed for industrial Reynolds roller chain; presumably similar stuff, but without the motorcycle price markup.
Alternatively Wurth HHS 2000 is similar and also designed as a high pressure lubricant, plus it might be more suitable if you have plastic gears in the mix.
Both have quietened down the gear trains on my Myford & Warco lathes

Bill

[halfnutParticipant @halfnut]

I use modern teflon-based motorcycle chain lube. Much less mess than the old grease and wax types. Spray it on and leave it to dry overnight before running the machine. It sets up into a nice high-tack but non-sticky coating. So it sticks to the gears but swarf does not stick to it.

[JasonBModerator @jasonb]

Also check the correct sideways spacing as not getting that right can cause the sides of the gears to rub even if you have set th emesh with the right backlash.

[old mart]

On old mart Said:

… try increasing the looseness of the meshing, I find that tight meshing makes the most noise.

Me too, and so does an overly loose mesh.   Like others I use paper sheet to set the gap, and experiment showed a double thickness of 75GSM laser printer paper gets best results on my Chinese lathe.  A 3 sheet gap is too much, and 1 sheet too little.  I don’t normally bother, but fiddling with the exact mesh between all the gears finds a sweet-spot where noise is noticeably less.

Although paper is recommended for spacing change gears, keep an eye on the type used, because paper is inconsistent.   Newspaper is much thinner and squishier than the heavy gloss used in posh magazines.

Gears are inherently noisy!   My lathe’s larger steel gears ring like bells, the sharp edges of the teeth audibly stir the air at certain speeds, and slight inaccuracies in tooth form and wheel diameter cause clatter.

One or more plastic gears in a train reduce noise considerably.   But opinion is divided: many perceive plastic gears as cheap fragile rubbish to be replaced with metal pronto versus those who want plastic gears to keep the noise down.  And apart from noise, a plastic gear in a train might be protective.  Hobby machines aren’t built to gouge metal quickly and a weak plastic gear in the train is one way of protecting a delicate tool from heavy handed owners.  The hope is the plastic will break, like a shear pin, before something more expensive. If metal must be removed quickly, buy a big machine, ideally industrial!

Final tip, only engage change gears when the lathe is fine-feeding or threading.

Dave

[Martyn Nutland 1Participant @martynnutland1]

Many thanks for all the advice and observations. Methinks I should re-check the mess with about two thicknesses of laser printer paper. But erring on the side of clearance rather than tightness definitely seems best. Then use motorcycle chain grease sparingly.

Thanks again. Happy Easter machining.   Martyn

 

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