Rhodes Bounty 2 propellor HELP!!

[Bcsr]

Hey there cruisers

As a long term owner of a Rhodes Bounty 2, I have had two bouts of propellor hassles.

Firstly, the original prop was not up to the recently installed Yanmar YM30, and deformed until it started clouting the rudder.

Last winter I admitted ignorance and got a qualified mechanic to fit a new prop.

The result? When going in reverse last week with the rudder full over, the new prop wedged itself in the blinking rudder again. So Tiare is out of the water with a scarred rudder and deformed prop, and trying to source the right one is proving difficult.

So... Bounty 2 owners... is there anyone out there who has a three blade prop on their unmodified p&j? If so, can you tell me the size, pitch and feather?

Btw I know the pictures are of a two blade...

I hope you can help...

Ben

[SwellGuy]

I’m not certain what you think the problem or the solution is here, but it sure looks to me like you need to either adjust your rudderstops to prevent it from contacting the prop, or get your prop closer to the boat (shorter shaft, and switch to a prop nut zinc instead of shaft collar zinc since there will no longer be room for it) so the rudder has more room to swing before colliding with it. Shorter prop diameter will also increase the extent to which the rudder can move before colliding with it.

I’d say the easiest is just chock your rudderstops to prevent the rudder from being able to make contact with your present prop.

On edit, it looks like you’ve already killed prop 2 by smashing the rudder into it, so just get the geometry right for prop number 3... Gonna get expensive if you’re replacing your prop every time you make a sharp turn ��

[SwellGuy]

Also- the only way a sistership’s choice of prop pitch is going to be relevant to you is if they have a similar engine and similar reduction ratio on their transmission. If it isn’t obvious to you why this is the case, I suggest you get some qualified help.

[Sailmonkey]

We went with a jbc aperture propellor. Our boat isn’t a Rhodes, but we’ve got a similar problem.

[Bcsr]

Hi Swellguy, Sail monkey.

Thanks for replying!

I probably didn't explain very well. The previous prop worked fine, and it should be possible for a prop to work in the space with the movement on the rudder without limiting it. To be honest this one looked big in the space, and I should have trusted my own judgement. However, i relied on the application of experts, to my detriment.

The prop is unfortunately FUBAR, with cracks along the bend point.

I do know the prop will be different depending on the engine and gear ratios too. Hence mentioning the engine type- which is pretty common for Bounty 2s! If anyone has a Bounty 2 with a 3YM30, then please do reply, then we can chat ratios offline.

Thanks

Ben

[Aksailor14]

If you want to do the work yourself get a copy of the Propeller Handbook
by Dave Grerr. It has all you need to determine the size and configuration required for the aperture.

Good Luck!

[TrentePieds]

Every boat owner owes it to himself to be able to do these simple kindsa calculations himself. If he can't, how could he possibly monitor and verify the quality of work done by "professionals"?

So here, as a start, is a Propeller Calculator. Gather the input data. Enter that data, and accept what the calculator tells you. IF, but only if, your input date is correct, the calculator will tell you diameter and pitch of an appropriate propeller. "Propeller Adjusters", people who make their living fixing people's bent props, use this very calculator, so you, too, will be safe using it.

https://www.vicprop.com/calculator.htm

But remember that the "Bounty" design goes back to the early '50s, way, way before honest sailormen put humongous diesels in their boats. Notwithstanding that a designer of no less stature than William Garden adapted this venerable design for "mass" production in frozen snot, the propeller aperture on YOUR boat is apparently NOT what is should be.

Judging by your pic.s, the tip clearance is too small to start with. The distance from the aft end of the cutless bearing to leading edge of the cutout in the RUDDER is too little, and the blade clearance with the rudder hard against the stops - if indeed there ARE stops - is too little.

You will save yourself untold future grief if you modify the cut-out in the RUDDER to provide the requisite clearances. The cut-out in the "deadwood" - the aft end of the keel - is probably alright.

The original engine was an Atomic 4 gas pot which, if I recall, ran at substantially higher RPM than your current Yannie, although the rated horse power was the same, viz 30. The propeller required by the Atomic was therefore of smaller diameter than the one required by the Yannie. No doubt the boat was re-engined along the way, and the then owner might have been a little weak on the basic concepts, and have failed to modify the aperture to accommodate the new prop.

Now, without dimensioned elevation of the two engines I cannot know whether mounting the Yannie in the same position as the original Atomic might have positioned the tranny/shaft flange an inch or three further aft, thereby pushing the prop shaft aft just enough for the prop to smack the rudder. The pic. showing the shaft zink shows a reasonable protrusion of the shaft, so if the prop smacks the rudder, the only sensible corrective measure is to modify the cut-out in the rudder until that can no longer happen.

Hope that helps

All the best,

TrentePieds

[Scaramanga F25]

Are your engine mounts solid?

[sazarac]

Originally Posted by Bcsr

Hey there cruisers

As a long term owner of a Rhodes Bounty 2, I have had two bouts of propellor hassles.

Firstly, the original prop was not up to the recently installed Yanmar YM30, and deformed until it started clouting the rudder.

Last winter I admitted ignorance and got a qualified mechanic to fit a new prop.

The result? When going in reverse last week with the rudder full over, the new prop wedged itself in the blinking rudder again. So Tiare is out of the water with a scarred rudder and deformed prop, and trying to source the right one is proving difficult.

So... Bounty 2 owners... is there anyone out there who has a three blade prop on their unmodified p&j? If so, can you tell me the size, pitch and feather?

Btw I know the pictures are of a two blade...

I hope you can help...

Ben

I have owned my B2 1962 for 32 years. Yanmar 3gm30f 1988 new. About 4000 hrs. My prop works perfectly with boat, engine combination. The prop is a Michigan wheel three blade 16 x 12, diameter, pitch. At 2800 rpm in calm conditions 6.5 knots. About 3/4 gallon per hour. I will add the transmission ratio when I get to my manual.

[stormalong]

From the picture it looks like your prop shaft is too long. Is it possible that the new engine install resulted in the position of the shaft coupling being farther aft and the that the shaft needs to be shortened a bit?

[sazarac]

I agree your prop shaft is protruding too far. My hub is probably 1/2 inch from contacting the cutless. The rudder can’t be modified without basically building a new one. The rudder shaft is continuous. I had to take mine apart to repair the flange connection to the shaft. It also looks like your cutless may not be seated in the shaft log all the way. My boat is in the water right now so I can’t get a look with out a 60deg dive. Email: tlsazarac@yahoo.com feel free to contact.

[Bcsr]

Hi there!

Thanks for your comments and advice. Sarazac, as it turns out you are pretty much on the money. The shaft has been shortened as well!

Tiare goes back in the water in a week's time with a shortened shaft, a new 16x12 three blade prop and a new cutlass bearing for good measure.

Thanks again everyone

Ben

[sazarac]

Originally Posted by Bcsr

Hi there!

Thanks for your comments and advice. Sarazac, as it turns out you are pretty much on the money. The shaft has been shortened as well!

Tiare goes back in the water in a week's time with a shortened shaft, a new 16x12 three blade prop and a new cutlass bearing for good measure.

Thanks again everyone

Ben

Let us know how it works out.

[Bcsr]

Hey chaps.



Just a quick note to say that Tiare has been in the water for a month now, and we have done a hundred miles in her (in some pretty heavy blows) since "the event".


The new prop is much smoother and more powerful too!


Off for a sail to the Isle of Wight this weekend and anchor off the roman ruins of Newtown Creek for my birthday...


Thanks again for the advice and support.


Ben