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[sparkey]

  Over many years I have been experimenting with different types of lubricants for my prop shafts,I am now using a mixture of oil and grease ratio of 4:1 makes it thinner than grease thicker than oil which gives less resistance than grease and does not run out of shaft like oil,the mixture of engine oil and grease works for me and I have had little bush wear since using this method that are your thoughts on this,Ray    

[john44]

Hi Ray,
that is the mix I have been using for a long time now.
I mix mine in a plastic bottle, with a paddle made from dowel & plastic
just make a hole in the bottle top for the paddle/mixer shaft to pass through
fit the bottle top, fasten the paddle in an electric drill, a quick burst and the mixture
is thoroughly mixed with no mess, and you pour what you need.
I just draw the mixture up into a large syringe which I take to the lakeside with me.

john

[radiojoe]

I always use Raboesch waterproof shafts/tubes a bit on the expensive side but good quality, you don't need the plugs of grease so no drag at all, but I do coat the shaft with grease on final assembly and in service just put a drop of oil on each end bearing / a-frame bearing, being waterproof there is not the need to have the inboard end above the water line, so the motors can be kept lower, I try to keep weighty bits below the water line if I can, I know some guys do fit standard shafts below the water line and rely on the plug/plugs of grease to keep the water out, but after all the work and expense I would consider that a bit risky . Joe

[Stavros]

straight grease thats all i use nothing else never had problems with shaft wear



Dave

[mersey dave]

On my Arun Lifeboat I used marine grease and up to now I have not had any problems.
Regards Dave.

[Peter Fitness]

straight grease thats all i use nothing else never had problems with shaft wear
Dave

Me too, Dave, and I've never had a problem either. I use outboard motor grease which is less likely to emulsify when in contact with water, although ordinary grease should be fine. Personally, I don't believe that any drag caused by grease has a noticeable effect on performance, particularly on scale models which run fairly slowly.


Peter.

[kiwimodeller]

I use a fishing reel grease from the local sports goods shop. Comes in a squeezy tube with a nozzle which makes it easy to apply, it is fairly fluid which means it flows in to the bushes well and water has no effect on it. Plus its cheap! What more could you ask for?

[Shipmate60]

Peter,
On my Graupner Prinz Eugen the 3 motors pulled 11 amps in AIR.
On regreasing the shafts with  fishing reel grease they now pull just about 4 amps.


Bob

[Peter Fitness]

Very interesting Bob. I have had a number of people tell me that grease puts too much of a load on a motor, but your observation knocks that argument on the head. Thanks for the info .


Peter.

[radiojoe]

I did note that Bob said REGREASING the shafts lowered the pull on the motors from 11 amps to 4 amps, that would suggest to me that the previous grease at 11 amps, did indeed put drag on the shafts.

[derekwarner]

Guys.....I read this a little differently after a lifetime in industry 

1. irrespective of the type of grease previously installed.........after sitting unused in cooler UK ambient temperatures I could see the actual lubricity between the shaft & the bush/s as being compromised/reduced...afterall, the grease has been previously spun off the rotating/stationary elements
2. cleaning & installing new grease between these same rotating/stationary elements will immediately increase the lubricity
3. Dow Corning 'Rubber Grease' is friendly to the environment....as is olive or vegetable oil  .............Derek

[kmmbcwebmaster]

I use a mixture of gear oil grease and copper slip mixed to a creamy consistency always worked for me 

[John W E]

hi all
 
firstly I am like many others - I use a mixture of grease with either a drop of 3 in 1 oil mixed in with it; or, a touch of gearbox oil but I dont fill the prop tube right up.   I only put about 1/2 inch of grease in and then load the shaft through the tube - run the prop shaft and run the shaft n motor in open air/under no load for about 10 - 15 mins.  I then remove the shaft, wipe excess grease off and then replace it.   Done that on many a model over the years and never had any problems.
 
What you need to careful of is if you put too much grease into the prop tube - that would cause drag.   
 
When I was working at Formica - we used to have a machine called the Steinemann Sander and we had problems there with what they call the main contract drum bearings over heating and burning the bearings/rollers out.  After we had replaced 3 - 4 sets we decided to call the manufacturers in - as we had done what was in the instructions.  (i.e. putting a new bearing in and filling it with grease).   
 
Anyway when the manufacturers engineers came - they replaced the bearings - they only put a fingertip smearing of grease on the new bearing around the rollers and what we were doing is literally filling all the bearings with grease =- i.e. as you would on MV Hibernia supertanker's main prop shaft bearings which went out of the River Tyne when I was working at the dockyards  another story....
 
Consequently too much grease in the bearings at high rpm was causing them to heat up and overload and seize.
 
aye
 
John