Mechanically almost there

I had a few days off this week so I got right to it cutting up the bike frames, and removing the parts i need.

First I needed to cut out the pedals and rear forks that I'm going to mount at the front of the boat to peddle with and mount the first sprocket that I will use to change the gears like riding a bike. I'm also leaving the front derail er on as well so I can have the ability to change all of the gears. Once that was complete, I cut out the bottom bracket from 2 other bikes which I will use as the lower units for eh propellers. I'll mount the propeller on one side and a sprocket on the other which will connect to the drive train of the boat.

After carefully cutting and grinding away 99% of the metal I don't need, it was time to start making the metal bracket to mount all of my parts onto a separate sheet of 1/4 inch plywood. This way, it will minimize the number of bolts going through the boat body.

The mechanics

The more I read, the more I searched online for more information. Building this HPB has become an obsession to put it in nice terms. I started drawing out ideas. Each idea allowed for more ideas in mounting everything and how it will work together.

I started thinking about how fast the propeller will rotate (RPM) and how can I figure this out. I want my boat to move, not just putt but move. It doesn't have to be lightening fast but certainly faster than an electric trolling motor which will move a 12 foot boat 6km/hr and 1600 RPM according to Minn Kota ( research into possible propellers I had done).

I also began thinking about gearing. Using the sprockets from mountain bikes so I can switch through the gears if I want to go faster or slower without changing my cadence. I also started thinking with additional sprockets, I could bump up the RPM. The largest rear sprocket on an 18 speed has 28 teeth. the Smallest sprocket has 14 teeth which will give me a ratio of 2:1. By putting several sprockets in line with each other with the chain going from the largest sprocket to the smallest sprocket on the next sprocket would double my RPM. With this information in hand, I had to find out what the "normal" RPM would be on a bicycle. I could easily keep 20km/hr on my mountain bike when cruising on the roads so I figured that would be a good cadence to measure all of this with.

The avg mountain bike tire is 26 inches so all I had to do is figure out how many inches were in 20km, how many inches a single rotation of the tire covers and how many times the tires rotates in an hour... the answer without boring you with the math is 640RPM. I later found this information online on a different site, however it's nice to see my public education wasn't a total waste.....LOL With my current configuration of sprockets and running dual propellers, I'll be running over 5000RPM, however this doesn't include the resistance of the water on the propeller, on the boat etc. I may find out that I can't even move the boat at all but time will tell and this IS an experimental boat and if this doesn't work, then i can at least say I tried and start changing things around to make it work. whether it be removing one of the propellers or changing the number of sprockets to lower the gear ratio and rpm.

I placed a few ads on Kijiji.ca looking for bike parts, and I found a couple of gents who had bikes for me to pickup. I made sure to explain to them my plans for teh bikes and that they would be cut up and used for the so no one would come back to me and say hey, that was a great working bike........ now its a great working boat...... lol All joking aside, it was great for tehm to give me these bikes. If not I would have had to pay for the parts, and after everything is said and done, I will price up what this would have cost, had I bought everything brand new.

I read an interesting article the other day about propellers and propulsion and one of the key points in the article was how dual propellers that turn in the same direction will cause the boat to track in that direction.... so I've encountered a good problem to think about. I have to make my propellers turn in opposite directions.... having the chain run in a figure 8 on the sprockets came to mind and when i tried to twist the chain it of course wouldn't twist they way I wanted it. I took it apart, then laid the chain on the sprockets the way I wanted and joined them together. When the chain was taught, it was pretty rough with the links rubbing and catching each other, but when i moved the chain to a lower gear with lots of slack, it ran perfectly, and never derailed with all of the slack..... I was impressed.

I think this is the most time consuming part of the project, taking aparts the rear sprockets to take the spokes off of teh hubs so all thats left is the axel, hub and sprocket. My son is learning very quickly about ball bearings..... lol

The Boat Plans

I've spent almost as many hours researching various websites for free boat plans as I have searching for HPB sites and trying to find anything that will aid me in building my boat.

I found a few sites that offered free plans if you signed up for a newsletter, (which I did and the news letter is pretty informative for me who's never built a boat before) to totally free plans from the 1950's which in it self it pretty interesting from some of the neat plans they have. There are even plans there for jet ski's (only using an outboard motor).

Here are a few of the sites I've checked out (repeatedly):

http://www.svensons.com/boat/

http://www.boatplans.dk/ (great newsletter and 2 free boat plans)

http://home.clara.net/gmatkin/freedes.htm

http://www.unclejohns.com/skiff/Default.htm (this is the site where I've gotten my plans)

The plans look simple enough and the price was decent at $27.00 however, one day while downloading a spare set of plans, I got the plans that had all of the dimensions included so I really got the plans for free and there are so many photo's of boats that people have built, I figured this is the boat for me.

Every great Project starts with an Idea

Many years ago growing up around my grandfathers cottage on Grand Lake, I often thought about how cool it would be if I could build a boat that I could pedal around the lake like a normal boat. Being only 12 or 13, I didn't have the money for a real boat, and certainly didn't have the knowledge to get around the mechanical aspects of building a pedal powered boat. Several years after this, working for a family member in a garage, I thought back to this and mentioned it to a frequent visitor, who mentioned they used to build these for duck hunters but not many people bought them because they were slow and cumbersome.

Now many years later, and having sold my boat while I was in school 6 years ago to help pay for the bills, I've come back to thinking about building a pedal powered boat. When I starting searching Google, it was quick to see there are a lot of sites on pedal powered boats or more commonly known as human powered boats. The majority of these boats are built for racing using kayak hulls and single gear pedal to propeller setup. I've always thought a real boat ( 12 - 14 foot boat ) with seats to take passengers, fishing gear etc.

As I searched online I found more and more information on these boats, and some instruction sites on how certain aspects were geared up. From there I also found many incredibly interesting sites on human powered vehicles. From snow machines to 4 wheeled bicycles with car bodies, all giving me ideas for future projects.

After many many hours of researching on boat plans (there is an abundance of free boats plans from popular mechanics from the 50's to private businesses that will sell you designs cheap and very simple to build. I downloaded a set of plans for a 12 foot wooden boat that uses 1/4" plywood and fiberglass cloth and resin to hold it all together. Pretty simple. I found another site ( I should say THE ONLY site I found) on how to build a propeller from scratch. Most of the Human powered boats (HPB for short) use remote control air plane propellers as normal boat propellers (what I've read from a mulitude of sites) are very inefficient for HPB's not to mention extremely expensive.

The other mechanical challenge I was faced with, was to find a way to turn the chain 90 degrees so I could connect a propeller to it. Sitting sideways (facing out the side versus facing forward) wasn't an option to me. I came across a site that talked about the compact twisted chain theory. If the chain is long enough, you can twist the the sprocket/chain on one end and the chain will stay on. there were some other points on this site about using a tube and a specific sprocket so that the chain wont derail or use miter gears which can be costly again from some of the sites that I've checked out.

After taking a lot of time thinking, dreaming and drawing things out, I decided I would go ahead and try and build this project with my Son who's 10 and very mechanical for his age (not to mention he can't get enough time with my tools and things he can take apart without getting in trouble....LOL) and we call it Project Green Marine........

Here are a bunch of sites on HPB's

http://www.humanpoweredboats.com/

http://www.pedaltheocean.com/

http://www.adventuresofgreg.com/24hour.html