Trojan Boat Forum

prowlersfish wrote:

Roll your eyes at me all you want. We can just agree to disagree. AGAIN.

No need to be snarky with me. I'm nice to you.

Commissionpoint wrote:

prowlersfish wrote:

Roll your eyes at me all you want. We can just agree to disagree. AGAIN.

No need to be snarky with me. I'm nice to you.

snarky ? me ? all in good fun

You now have a poll .

I repeat quadruple redundancy, taper plus 2 nuts plus cotter pin. IMO does not really make any difference, But I would go with big nut, little nut as jam and cotter pin and would forget it. If one is really worried use two big nuts the second one castellated and cotter pin.

after that weld it on!

Really the cotterpin is the coup de grace and cinches nothing coming off.

I agree with Commissionpoint on this one. I didn't go to Clarkson, but the University of Massachusetts teaches the same thing. The large nut keeps the propeller on the shaft, the small nut keeps the large nut from loosening. Keeping the propeller on the shaft requires more strength than keeping a nut from loosening, so the large nut is used first.

You can give a good argument both ways , Even engineers don't agree here . I real life I seen props say and props loosen boat ways .

It all comes down to a matter of perspective...

Think of it this way.

You are the Prop and you are on a shaft. We are turning you in a direction that you have to fight against to make my 17000 lb boat go forward. You being the prop will naturally want to climb up my shaft to avoid work. To keep you from avoiding work I will put a big nut on my shaft so you cant climb my shaft. And just to make sure I will put a smaller nut on my shaft to help the big nut keep you from climbing my shaft.

There you have it folks...

Big nut closest to the prop narrower nut helping the thick nut stay in place.

Barry

prowlersfish wrote:....After lapping in the prop , I install the prop using the big nut and tighten . I then remove it install the small nut retighten and install the large nut .

++1
Wow, somebody that does it right!
Small is left on first and large last. Tightening the large nut on the jam nut slightly distorts it jamming the threads. Having said that, walk through any marina and 90% of these are reversed in practice. I'm okay with that because I like getting paid to correct the results.

Big D wrote:

prowlersfish wrote:....After lapping in the prop , I install the prop using the big nut and tighten . I then remove it install the small nut retighten and install the large nut .

++1
Wow, somebody that does it right!
Small is left on first and large last. Tightening the large nut on the jam nut slightly distorts it jamming the threads. Having said that, walk through any marina and 90% of these are reversed in practice. I'm okay with that because I like getting paid to correct the results.

This is the way I do it also!!

In the case of a propeller, small nut first. Tightening the back nut last will remove some of the applied retaining force from the threads of the front nut. That being said, the rear nut will be carrying the bulk of the load which is why it makes sense to have the larger nut at the back.

The idea of using the large nut to seat the taper and then switch it out is a good one.

And put the darn cotter pin in!

larryeddington wrote:And put the darn cotter pin in!

First or last?

Big D wrote:

larryeddington wrote:And put the darn cotter pin in!

First or last?

pointed up or down

prowlersfish wrote:

Big D wrote:

larryeddington wrote:And put the darn cotter pin in!

First or last?

pointed up or down

Good one!