Running in metal gearboxes .... Best advice ?

[Wildboar44]

Hi Tankers .........

I have heard a few comments regarding "running in " metal gearboxes , I refer to the HL metal type (Not black gears ) .
I am sure I have read using tooth paste on a cleaned set of gears for several hours running backwards and forwards on
the bench . Also I am sure I read using T-cut an automotive cutting compound for paint or the type of cutting paste used
for grinding in valves on a car engine ?.

I have noted that some HL metal gearboxes are quiet and some are just plain noisy !, any advice you can offer for running
in metal gearboxes ?

Regards

Gordo

[Tankbear]

Hi Gordo

Ive tried runningin those gearboxes with everything from toothpaste to cutting compound and nothing made a difference. The metal must be to hard.

On mine I found the cogs to be inperfect one of them the axle was slightly off centre. So put that together and spin round at highspeeds equals noise.

Best bet if you want quiet you cant beat plastic just glue the slipping clutch.

Back to running in I normally run in the motors (not so much gearbox) at low power with no load I.e. gearboxes on bench fed directly off battery with both motors in series so get 3.6v each and only load is gearbox friction. An hour each direction should do to bed in the motor bushes.

Ian.

[jonger]

I found most of the noise is because of the play in the gears, which I reduce by shimming them, I posted a "howto" with photo's
http://www.rctankwarfare.co.uk/forums/v ... =38&t=9841

[Wildboar44]

Thanks for your advice Guy's ............


Thanks for the link to the how too jonger ......... those washers , are they 3mm ,as in M3 diameter ?

[jonger]

The washers on the shafts are 4mm (M4) as M3 are too small (they can be made to fit by filing them out) thats why I had M3 washers available to use on the bracing.
I found that most of the noise with those metal gears is not the teeth meshing but the gears rubbing against each other as they revolved, by shimming them in this way they do not touch and it gets rid of the "ringing" sound and the running in just makes the meshing a bit smoother so they run easier, doing both makes them a lot quieter.

[Wildboar44]

Thanks for your help once again Guy's , a shimming I will go !

[Wildboar44]

Just a quick update , the post was originally placed on advice on running in my new Sherman gearboxes which seem noisy ,
not got round to it yet but tonight I did pull apart the gearboxes on my current Tiger 131 build. After following your advice
jonger I placed brass M4 washers on the shafts and had to use M3 washers on the brass spacer bars .

Well I can say that this in a great tip , with the insulated sound covers I have in place and your modification the gearboxes
are super quiet !. Thanks again jonger , a great simple and low cost ( £2.55 Pk20) improvement . 10/10 Ace