pedaled powerd prop fishing boat?

First i will so HELP!! I am formost a fisherman before i moved i waded the shallow creeks around my home with minimal gear fishing.Now my new home provideds deeper creeks so i bought a 12 ft pungo kayak rigged it for fishing and loved it.But do to them paddeling i got tennis elbow and doctors told me to stop doing things that both it.So i sold it a bought jon boat and motor.This has made fishing a hassal and made it lose the peace i enjoyed in a yak.So this is my ideal if you can help our have better ideal thank you.Do to being young with a family i am not rich so high dollar gear boxes and fancy props will not work.The plan is to take either a 10 foot jon boat our build a gavin atkin design v bottom mouse.both plans include using chain or belt driven gears to a prop on a shaft.Rudder steering and reverse is a must not trying to break speed records but must be able to cover ground.I figure 15 to 1 gearing driving a 16x16 model airplane prop.I am 200 lbs and am wondering about draft,is a 16x 16 prop 16 inchs?,speed,shaft angle,and over all can this be done!

 

The 16 x 16 prop works well. An APC prop costs USD13. It will work on an inclined shaft but the blade loading is poor. It is best to have the shaft aligned with flow.

Fiddling around with anything but a precision gearbox like this:
http://www.mitrpak.com/product_datasheet.php?product_id=27
requires a lot of experimenting and learning. Helps if you can weld and do a bit of machining if you want to experiment.

Open gears like the attached picture are a bit cheaper than a gearbox but are more difficult to set up. Cheap right angle drives for drills will not stand up to the loads.

Unless you can guarantee that you will operate in weed-free waters an inaccessible prop will annoy the hell out of you. It only takes a single piece of weed to kill the prop. A 10ft cat will have easily to build hulls, will propel much easier than a jon boat, will be very stable and the prop can be lifted up to clean it.

Something like the Waterbike could be built for maybe USD500 if you shop around:
http://www.castlecraft.com/water_bike.htm

You need to decide if you want to go fishing or spend a couple of years developing and proving a pedal design that uses unproven parts.

These drive units have been used successfully:
https://www.msu.edu/~pengchun/
They are not as good as you could do with a little box and APC prop but they are reasonable.

Rick W

 

MY honor to git your replie i have read many of your post.I am able to weld and to also have machining done at work. i love the cat ideal but the raw size of such boat would be far to big for easy travel to and from water with both of the designs i am looking at 33 inchs is the widest.And i have seen some weed gaurds what do you think of them. also what do you mean by little box?

 

also would love for boat to be 80 lbs or less and i would love to have very little draft maybe a tunnel hull design

 

There is a link to a Mitrpak gerabox in my post above. This is the little box I am referring to. I tried all sorts of things before I purchased my first right angle gearbox. I now have 8 of them in various sizes. I wrecked two little ones trying to go too fast with them.

The human engine can sustain about 120W if in fair shape. That is 1/6th of a horsepower. It is not much. Anything in the water offers a lot of drag and you have to force it through the water. It will rob a good deal of the small amount of power available.

You can build cat hulls very light. They do not need to be any more than 3 to 4mm thick ply with some internal corner stringers. I expect 10 to 12lb per hull. So total boat weight 45lb.

The cat does not need to be very wide. 3ft is OK.

Rick W

 

Thank you agian any ideal were i could git plans for somthing like that.And i know this might sound weird but i figured that if the twist chain or belt did not work i have a rear end out of a yard tractor i could use for my 90 it would also allow me to use gears since the rear end provides reverse.also since i have read that gears do not have much use on water even though i do not understand that is i have the lower end off a evenrude 2.5 motor this would give me presion bevel gears that i could not break and i would be my 90 also how long would the cat have to be

 

Setting up a twisted chain drive that works reliably can be very frustrating. The little Mitrpak box weighs 2lb. Have you weighed the tractor box? Reverse is just a matter of pedalling backwards. There is no real point having more than one forward gear.

I have been through this discussion with many people and I can think of six people who have actually built drives. I have only convinced one guy to get a gearbox before going through the frustration of trying other things. There are still two guys using the Chinese twisted chain drive but the one guy who tried my boat wished he had bought a gearbox. It is a matter of how you value time. I expect it will take a year of fiddling to get a twisted chain drive perfected that will work both forward and reverse. The gearbox costs USD189 plus postage.

The hulls are very simple. Not much more than sealed boxes with pointy ends. For economy you would match the hull length to the ply you can get. Attachied image shows 8ft but is a bit short for your body weight plus a good catch. I would go at least 10ft - 12ft preferred. Probably aim to build it from 5 sheets of 6x4 ply.

There is a simple open cockpit hull shown on this thread:
http://www.boatdesign.net/forums/boat-design/camping-kid-build-raft-race-28311.html
The idea started out as a cat but you can see how it progressed. The hull was easy to build.

Rick W

 

not to be un greatfull but money is a big factor 200 for gear box marine grade ply wood goes 90 a sheet here and i figure 300 for prop shaft and other odds and ends puts us at 900 to 1000 usd.i can buy alot of diapers with that kind of money lol.garden tractor rear end wieghs 10 pounds welded lower end of the outboard is about 7 pounds i know this is going to be hard and if i could i would still be paddiling that was perfect

 

The gearbox should be the most expensive part.

I can get 4mm marine ply in 8X4 sheets for AUD32. I prefer other materials so I cannot comment on the quality as I do not use it these days. Others in the US could give you leads on this. You would need 4 sheets of 8x4 rather than 5. If you have a local door maker you might get some 1ft wide by 8ft offcuts. Not marine ply but will be weatherproof glue. I used to get these for AUD3 per piece before I started using composites. Would need anout 14 lengths but heavier than really needed.

Need to rescue an old bike from the local dump for the cranks, chainring, sprocket and chain. Usually cost nothing.

If you can weld or braze you can make a decent drive frame using the bike and gearbox. 10lb is a ridulous weight for a drive box on a boat like this. It will cost you half your power just turning over the shafts.

The 16x16 APC prop costs USD13 plus postage.

A decent pot of polyurethane glue and tiny stainless screws to put it together. Need some 15mm square timber beading for the stringers.

Best shaft is 8mm spring steel but 10mm machinable grade aluminium also works. Maybe USD16. Preferably roller bearings for the shaft strut but nylon bush is OK. Need a rudder.

It is a matter of shopping around for the best buys.

Forget the disposable diapers and use washable ones like my kids wore and wife washed to enable me to go sailing. (Can you still get washable ones??)

Rick W

 

Well i must be looking in the wrong places here smallist marine plywood around here is 1/4 inch and 90 dollars.And not much is made in the states anymore i cant even find some one who makes doors around here in the phone book.Would i be better of just adapting a kayak with some other form of perpulsion i would rather fish than enginer.i was hoping to have somthing done by april and this is not on a very good pace.any other drive systems with out paddeling?

 

Have you though about a little Minn Kota electric.

The neatest twisted chain I have seen is shown in the attached photo - built by Bill Goldthorpe. It uses 1/4" pitch chain and an APC prop. The ply boat is 12ft long and wide enough to be stable for fishing. It gets along quite nicely.

I have seen a gearbox and prop shaft in a plastic canoe that worked quite well. I would need to chase up a photograph. The key component was a litlle gearbox like the Mitrpak one linked earlier.

You could ask someone like Allan White using a private email to see if he can suggest economic ply supplier.

Rick W

 

I assume you have seen the Hobie mirage drive system:
http://www.hobiecat.com/kayaking/index.html
These are proving popular for fishing but are well beyond you budget when new. I have not seen what they go for in the second hand market.

Rick W

 

i have seen them but they have no reverse and that is a must i think i am in a hard place dont have time to devolpe it and cant afford to buy it.thought this would be a little simpler after seeing all the boats on here.

 

The key materials that you should keep an eye out for are.

Ply - marine ply is the best but outdoor ply with waterproof glue will give good service when glued up well and painted.

Used Bike - It is amazing how little use some bikes have that end up on the scrap pile. The pedals, crank, bottom bracket, crank, chainring, chain, minor sprocket and frame can all be used.

Right angle drive - I have seen unused boxes sell for half price and used one go for a fraction of original cost. It is worth keeping an eye out on Ebay. For example:
http://cgi.ebay.com/Andantex-Right-...ultDomain_0?hash=item4a98e767b9#ht_500wt_1122

If you want to have a go at a twisted chain drive I can give you more information on it and some contacts who have made good ones.

Where there is a will there is a way. Circumstances change so keep an eye out for the right materials and you might get the opportunity to put it together.

Rick W

 

I have the complete bike and will look for gear boxes any info on twist chain would be nice.I hate to keep bothering you but ow much do you think i would draft?