Does anyone know where I can get a propeller for a Beneteau 37? Mine has fallen off a couple of times due to use for a brass Woodruff key instead of steel. Brass is favored by the local propeller supplier and boat yard, since brass shears protecting the transmission. I did not realize that the design of the lock washer on this model makes the entire nut and prop come off, if the key shears. I now have the correct steel key from Beneteau, but the prop comes from France and may take 3 months. I'd appreciate any help.
Beneteau Propeller
- Thread starter Tony Bakke
- Start date
I don’t know where you can get one, but I do know the original fixed prop is measures 17x12 with 3 right hand blades for an ISO 25mm shaft. The suitable Flexofold replacement (which I recommend) is 16x12 3 blade. Any prop of those dimensions should work if you can get one fast than from France.
Hello Tony. Welcome to the SBO forum. I feel your pain losing your prop. There are several active members that are Beneteau 37 owners and I’m sure they will help out. If not maybe the rest could assist but only if you provide the specs on your prop. Shaft size, pitch, diameter, number of blades, composition and type (fixed/feathering/folding)?
As a start Olympic Propeller in Anacortes, WA are as good aa they get. Competitive pricing and fast and free shipping.
Olympic Propeller - Anacortes, WA
As a start Olympic Propeller in Anacortes, WA are as good aa they get. Competitive pricing and fast and free shipping.
Olympic Propeller - Anacortes, WA
I would consider a MaxProp feathering prop. Excellent reverse thrust, decent forward thrust and a streamlined profile when sailing that can add about 1/2 knot boat speed.
They will calculate the proper prop for your boat and shipped mine within a few days of my order.
www.pyiinc.com
Greg
They will calculate the proper prop for your boat and shipped mine within a few days of my order.
PYI Inc. | Max-Prop Automatic Feathering Propellers
Max-Prop is the leader in automatic feathering propellers. From 2, 3, 4 or even 5 blade designs we have a Max-Prop to suit your application.
Greg
Welcome !!
This may help with understanding the fitting process:
Lap-Fitting a Propeller to a Shaft - Marine How To
This may help with understanding the fitting process:
Lap-Fitting a Propeller to a Shaft - Marine How To
Changing the key stock alloy alone is probably not the answer. Remember the prop is driven by friction created by a well lapped joint between prop and shaft, also the prop cannot fall off unless the prop nut falls off too. The key and keyway are there to get you home in case the prop hits something. Beneteau "secures" the propeller with a tabbed washer. The tab goes in the keyway and the outer perimeter of the washer is bent to fit flat against one of the flats of the prop nut. This washer is a "use once" item. The two most common things that allow a propeller to move on the shaft and dislodge the nut are: 1) the propeller was not lapped to fit the shaft, 2) the propeller was key bound when installed. In other words, it was loose to start with.
The short of it is that the tabbed washer needs to be brand new every time, the key stock must be the right height, slide easily in the prop keyway, and fit very tight in the shaft keyway thus to avoid binding. And the prop bore must be clean and lapped fit to the shaft. 90% or better contact for maximum friction. Here is a good video: Just Got Shafted (youtube.com)
The short of it is that the tabbed washer needs to be brand new every time, the key stock must be the right height, slide easily in the prop keyway, and fit very tight in the shaft keyway thus to avoid binding. And the prop bore must be clean and lapped fit to the shaft. 90% or better contact for maximum friction. Here is a good video: Just Got Shafted (youtube.com)
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Thank you, everyone. I understand the process of fitting the prop now. Both times that we lost a prop, the Woodruff key was sheared off. When it shears, the bent tabbed lock washer does not hold the prop on, because it also depends on the key to stay fixed and not turn with the nut. I wish Beneteau had used a cotter pin instead of their tabbed washer. The last prop (an original Flexofold) was properly installed on the hard with correct lapping and the tabbed lock washer. It lasted 2 years. Should I have the next prop installed on the hard with that additional cost or in the water by an experienced diver? The diver says that he puts the prop all the way on without the key and marks the position, so when the prop is finally installed, he knows that it has gone on far enough for lapping correctly.
You beat me to it. I was just going to send the article.
If your prop is coming off, it is not due to the key shearing. that is only a symptom of another problem. The perfectly mated shaft / hub creates enough friction to hold the prop from turning. Case-in-point, the chucks on most machine tools like lathes and mills are just Morris tappers with no key at all. The fact that you are having so much trouble might be an indication that your taper is SAE and your props are metric or the other way round. The SAE and metric tapers are very similar and seem to be interchangeable, but they are not and will put much greater loads on the key than it was ever designed for.
The shaft on the boat is the original metric from Beneteau and the most recent propeller to fall off was original. The new one I ordered is from Beneteau for the B37. However, based on the excellent video in Marine How To on lapping, I plan to take the boat out of the water and go through the complete process. It is possible that the prop is not contacting fully and I want to verify.
