Hot motor

[ashley needhamParticipant @ashleyneedham69188]

Chris. There’s no right or wrong here in my view. Any method is valid, and these things don’t need the ultimate in lubrication.

Cant remember where I got them from, but a bearing firm I found did very thin “top hat” Teflon bearings and I used them on the dog-leg drive on the pontoon boat. Would be ideal for p brackets. Of course if P brackets are brass and have a reasonable thickness, they are self-bearing’d and obv water lubricated.

No, leave the thrust washer (nylon ones the best) as they have a job to do…mainly reducing wear on the prop-bearing face. Water will leach into the shaft, don’t worry about that!

Ashley

[Colin BishopModerator @colinbishop34627]

The washer provides a seal when the model is going forward, but at rest and when going astern enough water will be there to lubricate the joint. No need to worry.

It is also important that the whole of the threaded part of the shaft be outside the tube. Usually the prop itself plus locknut and washer will take care of this. If any of the thread is inside the tube it can act as an Archimedes screw and literally pump water into the model!

With regard to boats with P brackets, a plain tube is OK as the thrust should normally be taken by a collet on the shaft where it enters the hull tube (also using a washer!). The P bracket bearing is fully water lubricated and needs no grease.

Colin

[James Hill 5Participant @jameshill5]

Just out of interest, these were the bearings fitted in my Surfury. I bought half a dozen at the time. They were from America I believe and made to an imperial size. They are split down their length and close up to the shaft size when fitted. They were advertised as frictionless and are white metal lined. Provided a white metal bearing is well lubricated with clean oil , they will last a long time.

In my working days we used to re-metal white metal journals for shafts 10" in dia and then have to hand scrape them to a final fit. How things have changed!

Jim.

[Ray Wood 3Participant @raywood3]

Hi All,

As this is currently the only show in town ! I thought I may as well chip in

All the stern tubes I have used over the last few years have been Raboesch, Caldercraft & J.Perkins all came with metal bush's and work perfectly well with a drop of oil on the dry end as Colin said. I'm slightly surprised Greenpeace haven't raided model boat clubs for using oil tubes as a source of pollution

Perhaps they have bigger issues to deal with ?

Regards Ray

[GrumpsParticipant @grumps]

A quick postscript. First sailing at Sheringham boating pond went very well. My granddaughter Wren seemed very happy with her new boat. The 385 is more than adequate without a tube full of grease, giving more than scale speed. The boat shipped a teaspoon or two of water through the stern tube, which I suppose is acceptable. Guess it means frequent oiling of the top bearing though, as the oil will be washed out on each run. Thanks everyone for the sage advice – it is hugely appreciated!

[ashley needhamParticipant @ashleyneedham69188]

Well done Grumps, success…and all down to removing a bit of grease! (More or less).

A drip of oil, just one drip, before each sailing on the inboard bearing should be more than enough. Two teaspoons of water…nothing to worry about at all.

Ashley

[Author]

Posts