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Message |
    
newinertia
New member
Username: newinertia
Post Number: 1
Registered: 11-2008
| | Posted on Sunday, October 18, 2009 - 04:57 pm: | 
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Hi, Im from the midwest, therefor ignorant of all things nautical... well not really. I have been designing a classic looking boat that I would like to build and install a CPP on, but would like to find the simplest, and most reliable. I am handy with a lathe and there is a foundry locally, so I would like to build from scratch from silicon bronze. I have studied numerous patents from 1903 to 1983, and really dont know what is PROVEN in the maritime community, and what will hold up to a large torque load at low RPM. Id really like some input on this, and if you let me duplicate your system, Ill send you duplicate spares for free!
Skip- newinertia@yahoo.com |
miro
Senior Member
Username: miro
Post Number: 399
Registered: 11-2001
| | Posted on Sunday, October 18, 2009 - 09:12 pm: |
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While I agree that the challenge of pattern making, casting and machining a reversing prop is stimulating, you might be wise to consider the use of a Kitchen rudder.
Elsewhere on the OME Discussion board, you'll find a good deal of info about it.
And frankly, it's more efficient and much more fun.
I some pictures of a reversing prop mechanism, and it looks fragile to me. The reason that I have the pictures, is that the prop mechanism had to be re-built because of the wear. This was its second re-build.
miro |
newinertia
New member
Username: newinertia
Post Number: 2
Registered: 11-2008
| | Posted on Sunday, October 18, 2009 - 10:11 pm: |
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Thanks miro- Is that a Dippy in your pic? I have a copy of 'The Greatest Little Motorboat Afloat'
the story of the Dispro - Still read it once a year! I do understand your reasoning, but there were and are MANY models of the C.P.P.(controllable pitch propeller) made, and they are still the prop of choice on larger fishing boats, BUT modern systems cost $8,000 for a small ten to twenty horse system. Kasten Marine recomends them for all their boats. They really are robust with a shoe and skeg setup- the reason I want one is for efficiency, and low speed manovering, I cruise the Muddy Mo here in Kansas City, and the current is swift. I am not in any way trying to change your mind about what is ideal for you, but it is ideal for me. I have 45 or so original copies of patent drawings for this type of system, but patents dont tell you how many units were sold, what the drawbacks were to each model, or wich one is the one everyone swears by! That is why I joined this group, research and the very valuable input from you folks that have been there, and done that.
I do apreciate the Kitchen Rudder design, but it is not as efficient as the CPP. I now am using a 17 HP KOHLER vertical shaft mated by dual b section belt to the lower unit of a Johnson 50- see pic. With this, I get 36 mpg at 5.5 knts.at 880 rpm and have over 1000 miles of cruising on it in a year. total cost for the boat, electrical system, engine, drive sys, and Harley exhaust is $1000. I will be building my next boat nicer, but my little 'Sardine' just keeps amazing me with its feats of durability, and economy. |
newinertia
New member
Username: newinertia
Post Number: 3
Registered: 11-2008
| | Posted on Sunday, October 18, 2009 - 10:30 pm: |
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boatpaul
Member
Username: boatpaul
Post Number: 13
Registered: 05-2009
| | Posted on Monday, October 19, 2009 - 11:59 pm: |
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newinertia,CP wheels have their place,but on inland waterways with high levels of silt, their life would be short.In the best of conditions they are maintenance intensive and lubricants need to be enviromentally friendly.It would definitely be a great machineshop project though.
Goodluck! |
billschaller
Senior Member
Username: billschaller
Post Number: 304
Registered: 12-2003
| | Posted on Tuesday, October 20, 2009 - 10:14 am: |
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if I was going to make one, I would make a Roper.
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miro
Senior Member
Username: miro
Post Number: 400
Registered: 11-2001
| | Posted on Wednesday, October 21, 2009 - 08:46 am: |
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Yup - that is a DisPro in the picture.
Since you are familiar with the book, the back cover has a collage of 12 pictures - 6 of them are of my DisPro - Emily.
It is also the only DisPro in the recent wooden boat book - Wood and Glory.
BAck to your prop question - I haven't seen variable pitch props for on small boats except at antique marine flea markets.
And I hasten to add, I haven't seen many Kitchen rudders either.
Could it be that most folks just give a darn and put up with inefficiency and lack of maneuverability? If their boat goes straight and fast - that's all they care about .
I'll see if I can get some of the guys I know to take apart their prop system and let me take some pictures. Now that the cold weather is setting in, most boats around here are out of the water.
miro |
newinertia
Member
Username: newinertia
Post Number: 4
Registered: 11-2008
| | Posted on Thursday, October 22, 2009 - 12:20 pm: |
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Thanks miro- All Good Stuff! Thank you for maintaining Emily- I hope she can be enjoyed for generations to come. If you ever come across a dippy housing, Id like to have it.
Skip |
newinertia
Member
Username: newinertia
Post Number: 5
Registered: 11-2008
| | Posted on Thursday, October 22, 2009 - 12:28 pm: |
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Bill- Why do you like the Roper design? It looks interesting, but maybe overcomplicated with four blades? Thank you for posting it, do you know the patent #? |
steamroy
New member
Username: steamroy
Post Number: 2
Registered: 08-2005
| | Posted on Friday, October 23, 2009 - 05:02 pm: |
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Hi there,
I might have something that would interest you. It is a 20 in dia , 3 blade affair.
It is now at the Granenhurst Grace and Speed Museum, so it might be a while before I can get at it again.
Roy |
newinertia
Member
Username: newinertia
Post Number: 6
Registered: 11-2008
| | Posted on Friday, October 23, 2009 - 11:01 pm: |
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Roy- Would definately be interested in more info-
Do you have any model or mfg. info on it? What motor was it behind? 20" 3-blade would be nice for a Listeroid system- (ahem)....non-commercial of course!
The Boat Im designing is a Doosey- If your interested. I really appreciate you guys having an interest. |
bgoss
Senior Member
Username: bgoss
Post Number: 131
Registered: 12-2007
| | Posted on Sunday, October 25, 2009 - 05:20 pm: |
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Sorry to mess with this thread, but it's good to hear that you're back in the mix Roy.
Blair |
newinertia
Member
Username: newinertia
Post Number: 7
Registered: 11-2008
| | Posted on Monday, October 26, 2009 - 11:27 am: |
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Roy- Thanks for the info on Granenhurst Grace and Speed Museum- I went to the website, what a great thing for the preservation of all things nautical! I really appreciate it, and thanks for helping by preserving and donating, we will all benefit from that! As an inventor, one of my most prized posessions are a complete set of Popular Mechanics from 1938 to 1980, You can never come up with anything new, unless you know what has already been made! Keep on preserving. |
miro
Senior Member
Username: miro
Post Number: 405
Registered: 11-2001
| | Posted on Sunday, November 01, 2009 - 10:02 pm: |
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I tried to upload a video of SteamRoy's variable pitch propeller to You Tube, but didn't seem to work - and I tried to email you the video but my ISP indicated the file was too big.
miro |
jb_castagnos
Senior Member
Username: jb_castagnos
Post Number: 489
Registered: 07-2002
| | Posted on Monday, November 02, 2009 - 02:01 am: |
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There was a local company that made a boat called the Waymaker, used a Subaru engine mounted over the shaft with multiple belts driving the prop shaft. This arrangement allowed the front of the propshaft to be open. The control for the variable pitch prop came out of the front, attached to a control lever by a thrust bearing. He made his variable pitch props out of stainless, had a patent on the hub that made it weedless, the blades were mounted into a machined step that didn't allow the weeds to catch on it. The advantage of the prop is that it would remain weedless in forward or reverse because it always rotated the same way. |
miro
Senior Member
Username: miro
Post Number: 406
Registered: 11-2001
| | Posted on Monday, November 02, 2009 - 08:03 am: |
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Success with You Tube :-}
Here's the link to the prop at the Gravenhurst Grace and Speed Museum.
http://www.youtube.com/watch?v=gHcT8l8hCE0&feature=player_embedded
miro |
searcher
Senior Member
Username: searcher
Post Number: 367
Registered: 10-2004
| | Posted on Monday, November 02, 2009 - 08:38 am: |
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Very nicely done demo. Thanks. |
newinertia
Member
Username: newinertia
Post Number: 8
Registered: 11-2008
| | Posted on Monday, November 02, 2009 - 11:04 am: |
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Miro, Thank You! Great video! Just seeing it have the gears in my head turning, SteamRoy- That is one really great display! I am thinking this is the model I would like to duplicate. It is awesome! I hope you get better soon, just heard about the wreck. Best wishes and prayers.
Skip |
bgoss
Senior Member
Username: bgoss
Post Number: 132
Registered: 12-2007
| | Posted on Monday, November 02, 2009 - 07:26 pm: |
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Thanks for putting the effort into that Miro. How many words is a video worth? |
