prop clearance on cd30

[Ben Thomas]

I posted a question a while back regarding prop (aperture) size on the cd 30, as I am thinking of replacing the two blade with the autoprop, a self pitching three blade that swivels when put into reverse to have the same attack angle as in forward also self feathering to reduce drag.
they have a website at www.autoprop.com with mpeg showing how prop works.
So I was wondering if any of you folks that haul their 30s out in the coming winter months if you could measure the size of the aperture from center of shaft to rudder and hull etc. Larry D. thinks its 7.5"
and I never thought to measure when milagro was out of the water last year. Let me know if you would be interested in doing this for the info to be posted for us all. many thanks, Ben



btlandscapers@imagina.com

[John MacArthur]

So I was wondering if any of you folks that haul their 30s out in the coming winter months if you could measure the size of the aperture from center of shaft to rudder and hull etc.

The aperture in my CD-30 measures 8" from the shaft center to both the top edge of the rudder, and the bottom of the hull in the aperture. My (original, I'm pretty sure) prop is 3-bladed 13" x 12" LH. This gives the blade tips 1 1/2" clearance, top and bottom. I just measured it, so this isn't "I think ...". Engine is Volvo MD7A. Hope this helps.



jmac@laplaza.org

[Ben Thomas]

So I was wondering if any of you folks that haul their 30s out in the coming winter months if you could measure the size of the aperture from center of shaft to rudder and hull etc.

The aperture in my CD-30 measures 8" from the shaft center to both the top edge of the rudder, and the bottom of the hull in the aperture. My (original, I'm pretty sure) prop is 3-bladed 13" x 12" LH. This gives the blade tips 1 1/2" clearance, top and bottom. I just measured it, so this isn't "I think ...". Engine is Volvo MD7A. Hope this helps.

Thanks John, that figure gives me another 1/2" which may change the size of new prop. autoprop is saying to go to a 15" prop. that can't be right? I think I will still take Larry's advice and jump in. as the auto prop blades move for and aft when changing direction. thanks again, this is a great board!! Ben



btlandscapers@imagina.com

[John MacArthur]

Thanks John, that figure gives me another 1/2" which may change the size of new prop. autoprop is saying to go to a 15" prop. that can't be right? I think I will still take Larry's advice and jump in. as the auto prop blades move for and aft when changing direction. thanks again, this is a great board!! Ben

The clearance from the trailing edges of the prop blades to the leading edge of the rudder is 4 inches, and is even less (about 3 inches) from the front of the blades to the hull. This might be marginal for a self-feathering prop. Also, it might work ok with the rudder straight fore-and-aft, and interfere when you tried to turn. I think the 15" prop would be out of the question. Hope this helps.



jmac@laplaza.org

[Larry DeMers (The Real On]

Ben, I will be hauling the boat on the 23rd, and can measure that clearance exactly for you. My estimate was from observation committed to memory...notorious for "Senior Momentitis"..

Cheers!

Larry DeMers
s/v DeLaMer
Cape Dory 30 ~~~Lost my Wind instruments in a near-gale this wknd~~~

I posted a question a while back regarding prop (aperture) size on the cd 30, as I am thinking of replacing the two blade with the autoprop, a self pitching three blade that swivels when put into reverse to have the same attack angle as in forward also self feathering to reduce drag.
they have a website at www.autoprop.com with mpeg showing how prop works.
So I was wondering if any of you folks that haul their 30s out in the coming winter months if you could measure the size of the aperture from center of shaft to rudder and hull etc. Larry D. thinks its 7.5"
and I never thought to measure when milagro was out of the water last year. Let me know if you would be interested in doing this for the info to be posted for us all. many thanks, Ben

demers@sgi.com

[Ben Thomas]

Ben, I will be hauling the boat on the 23rd, and can measure that clearance exactly for you. My estimate was from observation committed to memory...notorious for "Senior Momentitis"..

Cheers!

Larry DeMers
s/v DeLaMer
Cape Dory 30 ~~~Lost my Wind instruments in a near-gale this wknd~~~

Somehow this reminds me of the game show "Whats my line?" with whats his name as host. remember that famous line "will the real Larry DeMers step forward". then there was always the fake putting in their 2-cents which everyone then recognized as the imposter! hah!!

Many thanks Larry looking forward to the info.... steady as she goes, Ben



btlandscapers@imagina.com