Fitting propellors

[LooverlijnParticipant @looverlijn]

Again I'm jumping the gun here a bit 'cos I'm not actually at the stage of fitting props yet but this is something that has always worried me… namely I've always been worried that when tightening the lock nuts my grip on the actual prop is going to distort the blades thus causing imbalance. Is there a good/recommended way to support the the prop or am I just being a bit cack-handed here?

[LooverlijnParticipant @looverlijn]

What’s the safest way to tighten prop nuts

[John W EParticipant @johnwe]

 

Hi there to make tightening props a little easier for yourself you can make yourself a small prop spanner quite easily from a piece of of flat steel bar – say 1/8" thick by say 1 inch wide by 3 inches long and at one end drill a hole slightly larger than the boss of your propellers. Then drill 3 equally spaced holes of roughly 1/8 inch diameter to take the steel 1/8 pins set into them. This makes a form of claw spanner. The pins locate over the blades of the peop and hold it securely thus enabling you to tighten the prop and the locknut fairly tight. I have attached a scribble to show you what I mean.

Also you can place a piece of rubber insulation over the pins to protect the blades of the prop.

aye

john

 

Edited By bluebird on 15/10/2013 14:15:35

[John W EParticipant @johnwe]

[Gareth JonesParticipant @garethjones79649]

Hi

I made a very similar tool to John, and it is shown in the following thread. http://www.modelboats.co.uk/forums/postings.asp?th=43640

Mine was much shorter, just a disc with the three pegs to limit the torque applied to the propeller. I think my original problems were caused by tightening the propeller and lock nuts to an excessive torque, in combination with thread lock. I probably did the damage to the blades when I attempted to remove the propellers some time later.

Regards

Gareth

Edited By Gareth Jones on 15/10/2013 14:57:48

[LooverlijnParticipant @looverlijn]

Thanks Bluebird and Gareth, I now feel much more confident about fitting my props and am glad I did raise my concerns as it appears that the props CAN be damaged by careless tightening of lock nuts. Anyway, I shall be making myself a prop spanner as your postings suggest.

Paul

[Kimosubby ShipyardsParticipant @kimosubbyshipyards]

Hi Looverlijn,

whilst on this topic, and without hijacking it, can I ask what must seem a "stupid question" of you all. I've just fitted twin shafts to a boat conversion, and added 4 blade props, LH and RH . The shafts come threaded at both ends with the inner end having a nut and two washers, the outer a nut and single washer. The washer is to the tube at each. The shaft has a note to "grease the shaft before running".

The question is, are these nuts at each end to keep the shaft in its tube, as they tighten up to give just a slight movement longwise in the tube without catching. If they are for that, as thats how they appear, then do I require to add another nut to act as lock nut for the propeller (or as I normally do, rely on thread lock.)? Threads are M4 so no problem to find one.

I made a Gareth designed prop tool way back when he first mentioned it – very handy too. And I note my trusty Thames barge has a large prop with nut facings already on its rim, so two spanners lock it on using a lock-nut, without touching the blades at all.

Kim

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