Little airboat motor.

[martyv]

Check it out...there is another one out there. http://anchorage.craigslist.org/boa/3049410060.html

And for all you doubters...I haven't tried mine out yet. Hope to next week. After getting it running well I'm a little afraid of it. not afraid of tipping over but of sticking my hand in the prop.

But I have to try it first.

 

[greythorn3]

Check it out...there is another one out there. http://anchorage.craigslist.org/boa/3049410060.html

And for all you doubters...I haven't tried mine out yet. Hope to next week. After getting it running well I'm a little afraid of it. not afraid of tipping over but of sticking my hand in the prop.

But I have to try it first.

u gonna take it up knik river? i can come record the even for you.

 

[Sid]

I do hope you try it out in a lake frist just to get the hang of it with life jacket you might need it , but lots of weight in the bow to help make it stable
my 2 CTS SID

 

[martyv]

I'm going to try it out in Jim Creek/Mud Lake area. Not going in a big river. I don't expect it to push me more than 5-8 mpg. We will see. If it works even half way decent I'll take it into the shallow lakes off of Jim Creek.

 

[rifleman]

Check it out...there is another one out there. http://anchorage.craigslist.org/boa/3049410060.html

And for all you doubters...I haven't tried mine out yet. Hope to next week. After getting it running well I'm a little afraid of it. not afraid of tipping over but of sticking my hand in the prop.

But I have to try it first.

martyv,

Be sure to cage and screen the propeller so nobody gets hurt. I’d recommend 1/2 inch mesh or finer to keep fingers out. Really, any solid object getting into the prop arc could cause part of the propeller to separate. This would cause a severe imbalance that could produce a catastrophic disintegration of the rest of the propeller and spinning hardware. It would all happen in the blink of an eye.

I hope the project is a success, but be careful!

 

[martyv]

martyv,

Be sure to cage and screen the propeller so nobody gets hurt. I’d recommend 1/2 inch mesh or finer to keep fingers out. Really, any solid object getting into the prop arc could cause part of the propeller to separate. This would cause a severe imbalance that could produce a catastrophic disintegration of the rest of the propeller and spinning hardware. It would all happen in the blink of an eye.

I hope the project is a success, but be careful!

Hmm. 1/2 inch mesh. I like the idea for safety but won't that block a lot of air and decrease effiency?

 

[rifleman]

Hmm. 1/2 inch mesh. I like the idea for safety but won't that block a lot of air and decrease efficiency?

martyv,

I just looked up some specifications on livestock fencing. Some of it uses 16 gauge wire to produce the mesh. I found a calculator that calculates 16 gauge to be .05082 inches in diameter.

So I took a theoretical area 10 by 10 inches (100 square inches). It would have about 20 vertical wires and 20 horizontal wires at 1/2 inch spacing. Thats 200 vertical linear inches plus 200 horizontal linear inches. 400 linear inches total times .05082 inches is about 20 square inches. So 16 gauge wire would block 20% of the intake area at 1/2 inch spacing.

The part of the cage beside the propeller tips would not block airflow, just the part of the cage upstream of the propeller. However, there would also be some turbulence introduced into the airstream by the mesh which would reduce propeller efficiency.

You could use a coarser mesh of 1 inch which would block about 10% of the airflow instead of 20%.

You might be able to measure the actual penalty with a fish scale by tying the stern to a solid object onshore and measuring pounds of thrust produced both with and without the cage and screen. Then, you could evaluate if the performance penalty is worth the safety benefit.

 

[greythorn3]

forget all that jazz, its been working for years no need to reinvent the wheel!!! you guys are the reason kids wear them stupid helmets now to ride a bicycle.