Prop shaft, tube, cutlas bearing and stuffing box

[O'Possum]

I am looking for insructions on how to build the drive works, especially the prop shaft, tube, bearings and stuffing box for use on a very small power boat that will use a 5~10 HP motor.

I have looked in several books from the library and looked on the internet and have not found that much information on what is required to do a hull penetration for a prop shaft that won't sink my little wooden boat. If some one can poke me in the right direction, I'll thank you greatly!

Gerald
AKA: O'Possum

[Dave Fleming]

Got a drawing of the deadwood or transom to hull connection?

[Ian McColgin]

Chappell's lovely old Boatbuilding should give you some useful thoughts.

[nedL]

Yep, First need to know what kind of boat. ;)

[O'Possum]

Originally posted by Dave Fleming:
Got a drawing of the deadwood or transom to hull connection?The boat isn't realy designed yet. I've got a pretty good idea of what I want though.

I think I can handle the outsides of the thing. Basicly I need a piece of pipe long enough to go through the bottom and cary the prop shaft, bearings and Stuffing box. I'm pretty sure I can handle the outsides of the thing. It's keeping water from running through it and keeping it turning I'm worried about.

[Bob Perkins]

Take a look at the Glen-L (http://www.glen-l.com) site. You can see a very nice selection of bits and pieces.

They also have a book on inboard motor installation that would help.

Take Care,
Bob

[Philip Maynard]

About 5 years ago I built "Cerlew" in Edwin Monk's reprinted 16 small boat designs published by Dover. I was also reading Ruel Parkers Sharpie book at the time and I decided to put in an engine. I stopped by a local go-cart shop and they had a Tecumseh 5 HP OHV sitting new on the counter and I measured it and figured I could get it to fit. I did not know anything about inboard installations and I went to Billings Diesel in Maine. I gave them the overall dimensions for the shaft and they did the rest. It's direct drive, goes about 4+ knots in idle and 5+ knots full power, (it sails faster). It really has more power than I need but it also does not get slowed down in head wind and waves. Th engine bed is just a wood wedge glued directly to the hull plywood with embedded throughbolts holding the engine down. I have a 7" protected propeller in a sailboat that draws 10" water. Im showing 2 photo's and I'll leave the rest as links so everyone does not have to download every photo.

http://www.pmaynard.lunarpages.com/temp/rudder.jpg
http://www.pmaynard.lunarpages.com/temp/skeg.jpg
http://www.pmaynard.lunarpages.com/temp/engine-bed.jpg
http://www.pmaynard.lunarpages.com/temp/engine-height.jpg
http://www.pmaynard.lunarpages.com/temp/engine-length.jpg
http://www.pmaynard.lunarpages.com/temp/seat.jpg
http://www.pmaynard.lunarpages.com/temp/prop.jpg
http://www.pmaynard.lunarpages.com/temp/cerlew.jpg http://www.pmaynard.lunarpages.com/temp/shaft-parts.jpg

[ion barnes]

This topic brings to mind, an idea that was shown to me years ago and have always wondered why it has not been picked up on. Specifically, a simple transmisson/clutch for small engines.

As I say, it was years ago, that I was shown a trans/clutch assembly used in railway scooters. They had to be inexpensive and cheap to repair.

The design consisted of a flywheel just as most you would find on a engine with a dry plate clutch, however the engine would be mounted so the flywheel is in-line with the centerline of the boat. The prop shaft is long enough to extend across the face of the flywheel, and has a keyway or splines cut corresponding to the diameter of the flywheel. Sliding on the keyway is a rubberfaced wheel that rides on the flywheel face, and the position is controlled by a yoke. A deprssion in the center of the flywheel for the mounting bolts is also the neutral position. Move the yoke and small wheel either side of neutral and you have foreward or reverse.

[PeterSibley]

That's a good system Ion, I've seen it used in rider mower drives and in big stuff like drive works on saw mill carriages. I wonder what the best material to reduce slip would be ?

[Stiletto]

I think old belt drives used resin to enhance grip, I wonder if it would work here.

[ion barnes]

Yes, sounds simple but have not been able to find one to examine. The couple of locomotive guys I have talked to know what I want but its a no-keeper as compared to other kinds of railway machinery.

[O'Possum]

have not been able to find one to examine. I have seen the type of transmition you talked about on a Snapper Rider mower. Just look for someone who has one of the rear engine Snappers in their shed.

You can stand a Snapper rear engine mower on its behind and peer at its bottom. The works are visible that way.

Snapper, Forrest Gump's favorite brand! I wonder what that cost 'em?

O'Possum

[Ron Williamson]

Ion
I have seen the same type of drive, on a snowblower.

It's called a brush plate,BTW.
R

[ion barnes]

Mowers and Snowblowers bah! Women's tools! But worth going to look at. Thanks

[Ron Williamson]

I agree but am still going to build a lathe drive that way,if I ever get around to it.
R