Re: Change Gears

Roger Bickers

Eddy, while i can't say with a definitive yes, i suspect the Rotella 15w40 i use (i own several 7.3 Powerstrokes)  has an additive that promotes a stickiness, unless its just a natural characteristic of the oil. Most times i apply with my lathe running and very little gets thrown off and it lasts quite a while.  My gear boxes get it too. Now to quieten down that god awful motor hum. Lol  roger

On Tue, Nov 20, 2018 at 9:34 AM, eddie.draper@... via Groups.Io
<eddie.draper@...> wrote:
Hi again all,

Roger has mentioned using SAE 15W-40 multigrade oil on the open gears of a lathe.  At 40 degrees C, a 15W oil has about the same viscosity as a ISO 32 straight oil, which I suspect is what SB oil for this application is already.  One hopes that the high temperature properties that relate to the 40 part of the description won't be relevant in this case.  I don't think that engine oil usually contains any tackiness additive.

I see, however, that a medium chainsaw oil typically has an ISO viscosity of 100 cSt at 40C, and does contain tackiness additives.  Doesn't need to be one of the posh expensive ones, so why not try that for quietening the gears if you have that problem?  Personally, I use a steam loco bearing oil of ISO 220 viscosity which also has a tackiness additive, for everything on the S/B because it is a stock item in quantity, except for the wick feeds to the headstock bearings (ISO 22) and the works in the saddle (ISO32 which happens to be a hydraulic oil).  In cold winter conditions, the saddle felts may also get the 32 instead of the 220.

And yes, the motor hum is one of the predominant noises except when the tumbler is engaged with the headstock on top speed (it's a 14.5" toolroom, 4 step flat puleys).  Single phase, you see (50 Hz, 230V in the UK).  The only reason I haven't fitted a 3 phase motor yet to make it quieter is that none have fallen into my lap.


On Tuesday, 20 November 2018, 13:43:05 GMT, Roger Bickers via Groups.Io <mr.concrete1964@...> wrote:

So you want to quieten down your lathe gears? Instead of using some cheap form of a gear, why not cushion the gear with a better oil that clings to the surface? Try a dribble of 15w40. 
Next thing youll wanna do is quieten down that damn motor you now hear hummimg. Lol Roger

On Mon, Nov 19, 2018 at 10:31 AM, yggsson . via Groups.Io
<yggsson@...> wrote:
Some pertinent points, in response -

None of that addresses the fact that people are usually much better off using a Form Mill ( Involuted Gear Tooth Mill ) and milling a Gear our of plastic than using a 3D printed gear.

The reason is simple - both are not actually proper Involutes. So accepting for the lack of them, the milled gear of solid plastic will be hands down the better prospect.

I’ve over a decade working in the 3D printing field, professionally. STLs are a compromise. The files available are more oft than not in accurate as well. And neither of those even address the fact that the machines themselves are simply incapable of creating an accurate Involute. And now, we’ve added in the fact that the equipment being used is not the most capable to begin with.

Making all this even more dismal is the fact Fusion360’s little free gear generator doesn’t actually output correct Gear Tooth forms, either. So doing all of this simply disadvantages the individual before they even get started.

If one is going to be accepting of a half measure, then the best choice would be to at least pick the half measure that is the better, more correct, practical choice.


Zahnrad Kopf
American Machine & Gear Works
Milwaukee, Wisconsin

> On Nov 19, 2018, at 6:40 AM, benjithestupiddog via Groups.Io <> wrote:
> Hi all,
> I'm a big fan of 3d printing also and lucky know a bit more about printer than I do lathes, otherwise this post would be worthless.
> Infill is ok, I wouldn't use hollow teeth but there are much more efficient infill patterns that the good old honeycomb, just a ton of perimeters and top/bottom layers should (no actual proof) be fine.
> I have only made one myself and not for a lathe, but I found PLA was fine its pretty resistant to oils, though high temps could be an issue for some the US members that actually get to see the sun (I'm in the UK) more than once a year as PLA will start to deform at hot summers day temperatures.
> If you need an odd size gear Fusion 360 has a feature that basically makes the gear for you, just pump in the numbers and its rendered for you, then just export and print.

Join to automatically receive all group messages.