Weed eater engine conversion

[*Ender*]

Originally Posted by docott

Hello. I've really enjoyed this thread. Lots of innovative ideas to build on. I've read through the entire thread twice. I have a few questions, but I'll start with this one:
How do I connect/couple the tube (in which the drive shaft resides) to the engine? I understand that this is simply done by attaching it to bottom part of a string trimmer I place of the original tube, but what if I'm starting with just an engine, like one of the scooter engines? I saw where John O'neal fabricate a coupling device, and that the Thai kit includes one. I don't have the capacity for fabrication, so any ideas would be great, or maybe I'm just missing something that someone could direct me to.

Thanks.

See post #282

[hoytedow]

Post #406 on page 28 shows a very simple configuration.

[docott]

Originally Posted by *Ender*

For those considering Chinese scooter or similar engines with a 78mm clutch and are in need of a housing assembly, there is Honda part off the GX35 powered trimmers that is readily available. The complete Honda clutch assembly #22260-VL3-D41 runs $35+/- delivered and is normally available in less than one week. The assembly contains everything you need to mate a 1" OD drive tube with the exception of four 6x20mm mounting bolts; it is set up for a square male on the drive shaft.

Ender

Ender, do you have a link/source for the housing you mentioned, Honda clutch assembly #22260-VL3-D41? I am, of course, doing my own search as well, but thought you might have a source. Thanks.

Spence

[docott]

thank you, Ender and Hoytedow.

[docott]

Nevermind-answered my own question

http://www.m-and-d.com/HON-22260-VL3-D41.html

[Erich_870]

Originally Posted by docott

Nevermind-answered my own question

http://www.m-and-d.com/HON-22260-VL3-D41.html

Please post up if you order it. I was looking at all the parts that are supposed to be included in that assembly and I'm shocked at the low price! It's over a 50% savings compared to buying each piece separately.

Erich

[docott]

Will do. I, too, was surprised by the low cost. You're right- other similar parts seem to cost about twice that.

[tom kane]

I have made small propulsion drives from several conversions but would a post hole borer not make an easy conversion and be robust and push a heavy boat well.
The attachment shows the borer shaft turned end for end and stripped a bit.
I did experiment with an auger drive and was happy with the end results.
Some two stroke motors can have the ignition turned to give running in both rotations.

[hoytedow]

I think 43 cc would work very well. I wish the airboat motor I threw together had been 43 cc. It would have performed better than the 25 cc I used. See page 41 this thread.

[tom kane]

The price is NZ dollar an equivalent outboard would be thousands of $

[Mark Wo]

Originally Posted by tom kane

I have made small propulsion drives from several conversions but would a post hole borer not make an easy conversion and be robust and push a heavy boat well.
The attachment shows the borer shaft turned end for end and stripped a bit.
I did experiment with an auger drive and was happy with the end results.
Some two stroke motors can have the ignition turned to give running in both rotations.

There is a company in Iowa that is doing just what you propose (using an auger bit as the prop). They shave it down just as you intend. People who own one seem to be fairly pleased with the results. They use a bigger engine than you propose (I believe they start at 6.5hp). Can't recall the company name but I believe it starts with an "S". Maybe try "scavenger"

Mark

[pistnbroke]

45 cc does not equal 6.5 HP and the idea is that the auger screws its way through the mud providing propulsion ..you should always consider with these projects if a mouse can power your boat even when its wheel is geared down....

[tom kane]

The advantages I found with the auger prop was that it would give thrust in sand mud weeds and even with a lot of weeds around it it still managed to push.Having no slashing propeller meant that any damage was minimal and the drive just slid over rocks and logs. Speed would depend on the rotation speed of the auger and most post hole borers run slow. I had 30 HP on one of my auger drive with a 3 speed gearbox. I would just love to have it back now.

[Mark Wo]

I have an ice auger that will drill hole after hole until the motor would run out of gas. It is really geared down however and I don't think it would spin fast enough to propel a boat. I wonder if the motor was geared differently if it would go through mud like you are trying to do.

I'm not clear Tom, did you already build one of these with the 45 cc motor or are you going to build one?

Mark W

[tom kane]

I have not converted a post hole borer but I did use an auger (a progressive pitch from butter packing machine ) on a boat with a Ford 10 inboard and 3 speed gearbox. The pitch of the auger would determine the amount of water and the speed (pretty slow without a gearbox with high ratio) Great in mud and sand and has a lot of prop walk. The screw was not steerable just ahead and a rudder to steer which was not very effective at times. I wish I still had it now.