Pedal Powered Boats

[Guest625101138]

Originally Posted by I57

Have been working on a new drive that has the flexible shaft on the side of the boat. Gear step up is 13.5:1 but there is a lot of resistance with the cranks hard to turn. The setup is a 192mm dia bike crank turning a 62mm dia gear which in turn is connected via a universal joint to a Involute gearbox at 3.3:1 step up. Looked good in theory, the prop is 200mm dia. I have too much reistance with a lot of effort to turn the prop. Can it be made to work better or am I going too high with the gearing.

Ian

Ian
The involute is really a heavy box. My view is that you will have a compromise drive using it just as the right angle drive. However you do not need to gear it more than say 2:1 if you want a smaller side mounted prop.

You will introduce a chain which will create a corrosion risk for salt water operation.

Another option to overcome the draft constraint is to use a lift-up skeg mounted off the stern that allow the prop shaft to come right up to the hull. You need to work out placement/size of rudder to avoid hitting the shaft when operating but this set up allows you to beach easily.

Rick

[Guest625101138]

Photos show my new CF tubular frame.

The video is Jeff testing the frame. He was pleased with the stiffness and the taller gearing with the larger 60T chainring driving the 14T sprocket. The day was calm although the smoke haze last weekend gives an orange tinge.

He is able to hold 12kph with heart rate between 150 and 160bpm. This is his sustainable level. He could hold 16kph for a long period but the tapered collar on the prop shaft started to slip.

Mike - The tube I got is 2.1mm thick and also high modulus. OD is 40mm. It is stiffer than the 0.9mm tubular steel used on my recumbent frame.

From the response you got it seems the tube you have is only 1.2mm thick?

Rick

[MLampi]

0.063 inches thickness for the inner tube and 0.065 inches for the outer tubes, so about 1.6 to 1.65mm.

The inner tube is 1.25" OD.

Michael

[Guest625101138]

Mike
This is the place where I got mine from:
http://www.cstcomposites.com/stock_on_hand_web.htm
This is their "In Stock" list. I got two offcuts that enabled me to do what I wanted without waste. The prices are in AUD which makes them a bit better in your dollar.

What I like about this place is the range of sizes. You can also get different modulus layups. I guess this is achieved with different types of CF and higher proportion CF to epoxy.

I made the mistake of placing the order in early January and dealing with one of the shop hands rather than a sales person. He screwed up the cost and charged more than the listed price. I am still to get it settled. It should have cost AUD306 plus postage.

Anyhow I am very pleased with the frame and believe I have close to the best possible set up now. It can all be made without any welding. If you force the epoxy curing you could make a frame in a day with only a couple of hours actual work.

Total weight of the frame with complete drive and seat can be done under 5kg. I also intend to make the outriggers a slide fit into the extended tube beneath the seat. This will take out about 1kg from the outrigger support.

Rick

[MLampi]

For several months I've been using a foil profile aluminum rudder based on an extrusion that I bought from a surplus vendor on the Internet. That rudder was much smaller than the spade rudder that is normally shipped with the Cadence pedal boat. In spite of its smaller size it turned the 19 ft. 3" boat with much less drag than the stock rudder and handled itself very well in ocean waves and chop.

Unfortunately, that same small rudder was an extremely poor performer when the boat was going in the reverse direction. The stock rudder worked quite well in that situation, so much so that even with a light wind one could parallel park.

Anyway, at last weekend's race around Jetty Island by the Port of Everett, WA, I managed to hit a submerged rock with both the prop and the rudder.

The propeller shows absolutely no damage, but the rudder broke cleanly from the spindle right at the welds. Apparently it wasn't quite as compatible as I thought with the 6061-T6 spindle.

I'm going back to the stock rudder - at least for a while. We'll see if having the better reverse steering is as nice as I remember it, and if the drag in the forward direction is not much different from the foil rudder.

Michael Lampi

[I57]

Had an idea for modifying my boat by making it into a proa.
Main reason is to enable me to raise the flex shaft out of the water and launch off the beach. Also reduce friction from the shaft rubbing in the centreline slot. The hulls will be 2m apart so should be ok for stability, anyone know the best position for the rudder?

[MLampi]

Originally Posted by MLampi

I'm going back to the stock rudder - at least for a while. We'll see if having the better reverse steering is as nice as I remember it, and if the drag in the forward direction is not much different from the foil rudder.

Michael Lampi

It's been a couple of races now and yes, steering in the reverse direction is now possible and quite good.

It is hard to determine if there is any reduction in the conversion of the prop vortext to forward thrust afforded by the flat plat rudder vs. the foil rudder. There seems to be, but without real measurements and a consistent motor powering the vessel from test to test it is really conjecture.

All I know is that it seems harder to exceed hull speed.

At last weekend's Lake Whatcom race, which is about 12.5 miles long, we had a good headwind for the first half with waves up to 1 to 1.5 feet. I wasn't making as much headway into the wind and against the other racers as I expected and averaged only about 6 mph. The return trip with the wind was a fairly hot slog and my average speed was only 6.5. The waves were traveling slower than the boat and turned into speed bumps.

At the end I summoned the last of my energy in a sprint to catch a double FSK, but it was too little too late and they crossed the line before me.

I think I'll try another foil rudder, but this time it'll be bolted to the spindle. Reverse steering is nice, but I can use my canoe paddle. In racing it is 99.999% forward that matters.

Michael Lampi

[Guest625101138]

Originally Posted by I57

Had an idea for modifying my boat by making it into a proa.
Main reason is to enable me to raise the flex shaft out of the water and launch off the beach. Also reduce friction from the shaft rubbing in the centreline slot. The hulls will be 2m apart so should be ok for stability, anyone know the best position for the rudder?

Ian
The problem with the single outrigger is that you rely on its weight for stability in one direction. I will be surprised if you do not have an unintended swim if you are out in the bay in a good breeze. Outrigger canoes have paddle and foot steering to help keep them upright.

Also with a single outrigger you are always dragging the outrigger. With twins you can carry the outrigger weight on the main hull.

Rudder works best where you have it. Higher aspect is more efficient but you also have to consider draft - 300 deep by 80 long and 20% thickness should be enough.

Rick W

[I57]

Rick, reason for trying the proa is to enable me to lift the shaft out of the water. The centre of the gearbox is over the edge of the boat giving the shaft a clear run. Need to make a bigger outrigger but apart from that I don't need to rebuild anything. With the current layout the two outriggers are always in the water and is virtually a trimaran, this way eliminates two short hulls for one longer one.
With the boat now there is friction on the shaft in the centreline slot as well as drag from the skeg, so new layout has to be better. Other point is standing in cold knee deep water to launch the boat is not good going into winter.

Ian

[Guest625101138]

I have finished V14 hull.

The build was very simple and did not take a lot of my time although waiting for the epoxy to cure slows the process.

Overall I spent approximately 38 hours to make the hull. This was done over 5 weekends and does not allow for the time taken for epoxy and paint to cure.

A rough breakup of the time is:
Week 1: Make CF-Klegecell flat panels including cutting - 10 hours
Week 2: Build stations frame and join panels - 8.5 hours.
Week 3: Fair the hull - 4 hours
Week 4; Sand hull, set mounting points - 4.5 hours
Week 5: Paint and fit drive and rudders - 11 hours

The bare hull weighs 11.5kg. The boat with drive frame and rudders weighs 19kg. The outriggers add another 3kg. It is heavier than my target but lighter than V11J. I have also made the outriggers so they plug in rather than swing up. This means for handling I have an extra trip to the car but I can actually carry the main hull with drive in one hand.

Rick W

[Guest625101138]

Took V14 out on the water for the first time today. I am very pleased with how it went.

Taking a few kilograms off the weight and reducing length by 1.2m makes for a much more manageable boat.

It all works well with just a bit of tuning now.

I am not in top condition right now so hard to tell how it performs against V11J. I will not know until I have spent time to build back my condition. It pushes up to 11kph quite easily but then seems to get harder to sustain above 14kph than I recall V11J. Above 15kph I get the impression V14 wins out though. I have already got above 17kph and my condition is not real good after 7 weeks of doing little exercise.

Rick W

[I57]

Rick, new boat looks good, must be easy to transport and setup which would be a plus. You mentioned the outriggers plug in, how do you secure them?
I'm still carving up my boat and making it into a proa, have removed the centre slot and patched the hole. My aim is to launch off the beach and am fitting a swing up rudder which has meant modifying the stern. The outrigger is 3m long x 76mm wide and 2m out from the hull. Will be using the involute gearbox with a 8mm dia. steel shaft which can be pulled up out of the water.

Ian

[Guest625101138]

Ian
I slide the square of the outrigger into the CF tube that supports the seat. I have a piece of nylon either side of the square tube but rounded to match the round tube. The tubes are held together with a bolt and small threaded hand wheel.

Rick W

[Guest625101138]

Ian
How are your boat mods coming along?

Lysterfield Lake is shedding a lot of weed right now with the cold weather. I decided to give your area a try. I spent a couple of hours at the Aquatic Centre near Carrum.

Is this where you go for testing?

It was a fresh morning but OK once warmed up. The wind came in about an hour after I got there so some variation in speed depending on the direction. I did 5 full loops so a total of 20km in 2 hours. The lack of weed and reasonably long run helped the average.

Rick W

[AmbitiousAmatur]

This is not quite as portable, but an interesting design nonetheless. It would be great at campgrounds on the water.

http://www.autocanoe.com/