Pedal Powered Boats

Maybe titanium has a similar coefficient of expansion. Found Centa Corp., Westmont, Ill.

 

Carbon tube source

Rick,

You should have asked me. I can get five 6' sets of carbon tubes with perfectly nesting carbon tubes for that same price. They are made in Canada.

These tubes are used for paddle shafts or, in my case, akas. Very light, very strong.

Michael

 

Mike
Is there anywhere I can see a price list and sizes available.

I do not intend to buy any immediately but will probably buy more in the future.

Rick

 

New Boat

Took the boat out today with a 8mm steel flexible shaft, worked much better than the 6mm. When pushing hard felt a bit rubbery, would a 10mm shaft be better? Shaft is 2100mm long over a length of 2000mm and 600mm height, works very smoothly. The housing in the skeg is to keep the shaft in place and all the thrust is taken at the gearbox. Windy out today but boat handled well (nothing broke this time). Got an interested spectator to take the boat out so I could get some pics and see how it trims. Have put on a smaller rudder in an effort to improve performance, still working on outrigger supports and am looking at quick release clamps.

Ian

 

Ian
I expect the 8mm gal steel will have limited life. Maybe 200km. You should keep a log of hours so you know how long it will last.

If you go up to 10mm it will have even shorter life and you are starting to load the strut. A 10mm shaft may even yield with the initial bending.

Another way to reduce the rubbery feeling a little more is to alter the prop pitch so you spin faster. This may not suit your natural cadence though.

Rick W

 

Red Cross have updated the handicap results list for the 2008 Murray Marathon:
http://www.redcross.org.au/vic/murraymarathon_results_handicap.htm

I managed 49th on corrected time. I suppose the challenge is to do better next time.

Rick W

 

I went for a run down the Yarra River today.

Melbourne's on-water boat show is on this weekend so it was a good reason to journey down the River to Docklands where the boats are moored. The round trip was 29km on the GPS and it was a fun day. The middle reaches are leafy and cool and the river opens up to the port area after the city so a constant change of scenery with plenty of dragon boats, rowing boats and pleasure cruisers.

A very pleasant way to spend 3 to 4 hours.

Rick W

 

Yarra cruise

Rick your cruise down the Yarra would have been great, where did you launch? Did you have a problem with larger boats seeing you in the busier parts of the river?
Had the boat out last week and developed a leak which I didn't notice until I saw the draft marks on the outrigger had changed from when I started. I had sunk 30mm deeper in the water and couldn't lift the boat out of the water, took off outriggers and drive and punched a hole in the hull to drain the water, took about ten minutes to empty. There were several hairline cracks in the hull from when I dropped it putting on the rack in the garage the previous week. Didn't seem serious at the time but even a slow leak can build up over two hours. Problem with the current set up is the big fixed skeg 500mm deep, makes the boat awkward to carry and launch. At the moment with the hot weather wading out up to your knees is not a problem. As a result of all this I am putting a side lifting flex shaft the same as Ricks and a swinging rudder so I can launch in shallow water. Drive setup is a 192mm dia bike crank connected to a 62mm dia gear attached to 3:1 right angle gear. Once I have patched up all the holes and put it all back together I'll see how it goes.

 

Ian
I launched at Yarra Bank Reserve off Bridge Rd Hawthorn. There is a car park on the river. The bank is quite steep but I managed to get the boat in and out OK. There is a school rowing shed about 100m downstream but they are not open to the public.

I am going to look around for another more convenient spot. I was a very easy run because there is a plenty to look at. Not at all boring.

In the narrow sections you need to keep an eye out for rowers but once it opens out near the city there is plenty of room except under bridges.

I went to Lysterfield today but the park is closed because they are concerned about fires. I understand we got to 46.5C. That is close to what you could expect at Marble Bar.

Will see what tomorrow brings.

I thought you had taped your seams so they would take a bit of a bump.

Rick

 

Leaky boat

Rick, I did tape the seams and most held except for a couple of places but that was enough to take on water. It was more than a bump, dropped from 1.5m onto a concrete floor, maybe it could have been worse. I raised the outriggers 20mm on the last outing and could probaly go higher as the boat is still very stable. Should be ready in a week or two, the drive will be much easier to change as the right angle gear box can easily be changed as well as the prop without carving up the boat.

 

Drive Problems

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

 

Maybe you want to use an air propeller rather than a water propeller.

Even the Cadence, with its 8.5 inch diameter propeller, uses a 6.5:1 ratio. Some folks prefer 7:1, but no one wants a higher ratio.

Michael Lampi

 

Nimbus Paddles & carbon & fiberglass tubing

At long last I got pricing from Nimbus Paddles, the makers of the tubing. Here is the letter they sent me:

Note that apparently the inner tubes are actually sanded to fit inside. This is a rather nasty process when dealing with carbon fiber and they won't warrant the strength of those tubes as it will abrade the carbon fibers. Sigh...

Michael Lampi

 

High Gearing

Mike
I was trying the high gearing as I thought it would be easier for launching in shallow water, and less prone at hitting logs etc. Can't seem to get it to work so will go back to previous setup with 450mm dia prop and a 3.3:1 gearing. Have to carry boat into knee deep water to launch which is not a problem now that it's hot but trying to come up with an alternative for the winter.

 

you folks are AMAZING!

150 watts is NOTHING! Congrats on a world record, and congrats to all of you who have the perseverance to make your own boats, then make them GO!