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[chris_suffolk]

Hi,

Back to building a tug, running dual props. Prop shafts etc fitted many years back when the boat was initially started, but they are just tubes with shafts and no bearings (though as I recall they were from a reliable model seller of prop shafts at the time). Have packed with marine grease, and in the bath I get no water in. Props and motors turn easily, with no vibration, and revs are quite low, even flat out spinning in air = guessing about 1000rpm or less given spec (pitman 24v geared 6:1, running on 12v batteries)

Should I be worried I have no bearings?

Guess things have moved some-what over the years as all props seem to have bearings these days.

Any help gratefully received.

Chris

[Tug-Kenny RIP]

If there are no leakages and she runs smooth then I would tend to leave it as it is.

Hope this helps

Ken

[chris_suffolk]

Thnx.

Taking the shafts out, there is an 'indent' on the inboard end. I.e. the tube thins slightly about 1/2 cm from the end (definite ridge as I push the shafts back in) Is this what they call a self lubricating brass bearing?

Anyway, feel happier now as it means the shaft is wider down its' length than at the (inboard) end, so grease should hopefully stay put, washers each end helping to hold it in too.

[malcolmfrary]

Packing the tubes with grease has probably created a brake.  Oil for lube, just a plug of grease to keep the water out without introducing a lot of drag.