I had planned to change my 15x15 two blade prop for a three blade 15x11 on my 1986 H34. However, I have located a 3 blade 15x12 prop. Would the 15x12 work ok or should I have it re-pitched to 15x11? Many thanks for your advice. Bob
H34 Prop Question
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Bob,
Don't get stuck on that diameter. Go for as big a wheel as can clear the hull. But gawd man, why do you want to install a fixed bladed prop? You'll be towing a bucket under sail.
Don't get stuck on that diameter. Go for as big a wheel as can clear the hull. But gawd man, why do you want to install a fixed bladed prop? You'll be towing a bucket under sail.
careful with the prop sizing!
The gap between prop blade tip and hull should be at minimum 15% of the prop diameter. As far as the pitch goes, Michigan Wheel's website has a prop size/pitch tool. I'm attaching a link to it. There are also other prop sizing tools around the Internet if you look for them. Fred's right about the fixed prop though. A three blade fixed prop will add significantly to drag under sail. I'm currently considering a folding or feathering prop for my H30.
The gap between prop blade tip and hull should be at minimum 15% of the prop diameter. As far as the pitch goes, Michigan Wheel's website has a prop size/pitch tool. I'm attaching a link to it. There are also other prop sizing tools around the Internet if you look for them. Fred's right about the fixed prop though. A three blade fixed prop will add significantly to drag under sail. I'm currently considering a folding or feathering prop for my H30.
15x15 is my current 2 blade prop
Fred, My current prop is a 15D x 15P 2 blade. I am a senior citizen and find that I am now doing more motoring than sailing. In reviewing 3 blade recommendations for the H34, seems most use a 15Dx11P 3 blade prop. Having a 15D x 12P 3 blade, I can use it like it is or have it repitched to a 15D x 11P. Just wondered how much difference the 12 pitch would make. Thanks, Bob
Fred, My current prop is a 15D x 15P 2 blade. I am a senior citizen and find that I am now doing more motoring than sailing. In reviewing 3 blade recommendations for the H34, seems most use a 15Dx11P 3 blade prop. Having a 15D x 12P 3 blade, I can use it like it is or have it repitched to a 15D x 11P. Just wondered how much difference the 12 pitch would make. Thanks, Bob
When I purchased mine 3 blade I started
with 15" * 12" which was only getting me to 2900 rpms at WOT... I had it re-pitched to 11" ..now I get 3400 rpms at WOT which is where you want to be. So yes get it re-pitched to 11.. I learned it the hard way since I ordered the prop new and when for 12" and blew it... By the way it made a HUGE difference in vibration. Hey Fred, I realize there is more drag with a fixed three blade but I don't race..Motor sail often "I'm on a mooring and need to charge the batteries" so it's not a big deal to me.. The boat is still fast enought to suit me. and man it made things MUCH smoother no more rattling of the cockpit seats locks and so on.
with 15" * 12" which was only getting me to 2900 rpms at WOT... I had it re-pitched to 11" ..now I get 3400 rpms at WOT which is where you want to be. So yes get it re-pitched to 11.. I learned it the hard way since I ordered the prop new and when for 12" and blew it... By the way it made a HUGE difference in vibration. Hey Fred, I realize there is more drag with a fixed three blade but I don't race..Motor sail often "I'm on a mooring and need to charge the batteries" so it's not a big deal to me.. The boat is still fast enought to suit me. and man it made things MUCH smoother no more rattling of the cockpit seats locks and so on.
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