• 14th May 2007 - By adventuresofgreg

    [youtube=http://www.youtube.com/watch?v=W_DGttuv6gE]

    I got my new prop yesterday and hauled everything out to the lake for a quick test and training session. Rick Willoughby made it for me and it only took about 1 week to get here by mail. From Australia!!


    I could tell immediately that it was different because my cadence to produce power was about 10 rpm slower than my prop. It was also faster! On average .5 kph faster at 150 watts. I did some speed intervals on 10 watt increments and here is the result as compared to Ricks estimate:
    We’re getting much closer. I still think the remaining gap is due to the hull shape.


    On the agenda for this week is to get my HID headlight installed on WiTHiN. We’re still waiting to hear back from the city of Calgary as to weather I will be allowed to use the lithium polymer batteries for the light on the reservoir. My proposal to them is to have the batteries tethered to the boat or the dock at all times.


    I also need to deal with the hydration IN/OUT systems. A water bag for hydration, and a ‘dirty water’ bag for outgoing. This bag will be handed off to the crew about once per hour when I circle around to the home base dock where I will pick up a new water bag and what ever food i require. For comm, I have decided to just use my cell phone instead of my two way radio. It’s lighter and the battery should last all day.

    I am testing out my Trimble Recon PDA. It features a GPS with moving map software. I downloaded a detailed photo of the Glenmore reservoir from Google Maps and added it to the Fugawi GPS navigation software. It worked perfectly!

    I also want to experiment with a video iPod, or portable DVD player. This would be a great way to take my mind off the monotony of going around and around in circles for 24 hours. The advantage to a DVD player is I can just stick any DVD in to watch it on the big screen. The disadvantage is poor visibility on the screen during the day, and poor battery life. The advantage to something like an iPod video is a bright screen and good battery life, but here in Canada, you can’t buy any video content from the iTunes music store – that sucks.

  • No Responses to “new prop – 1/2 km/hr faster!”

    • Ryan on May 15, 2007

      As someone mentioned in another comment it might be worth considering building a streamlined cover for your body. I know the wind can really kick up on the reservoir. If you are pedaling into a 10kph headwind (which I would expect to happen for some time any day in Calgary) that would be 20kph wind speed which could really affect your speed. Also, looking at your drive leg the gear box seems like a huge drag. I would do everything i could to try and reduce its size perhaps even changing to a drive shaft even though it is less efficient and something you haven't dealt with before. It looks like you have a fairly good computer model for speed, what happens if you change the parameters of the drive leg in the computer model? Perhaps it is too close to the 24hour record attempt to mess around with that, but it might be something to consider for next year.

    • ryan on May 15, 2007

      One other thing, have you considered reducing your rudder size. Judging by the video, you don't have any problem turning. Maybe build some smaller rudders until you reduce the drag as much as possible.

    • Anonymous on May 15, 2007

      In response to Ryan on the drive leg – You are correct. I could not tolerate the drag of the gearbox/chain combination that Greg has opted for but it is a compromise to enable use of the SRM power meter. The power meter is useful for development purposes.

      It would be possible to reduce the drag on the leg substantially by using another box for pedals rather than the chain. The drag on the leg would be around half the current 30W at 9.5kph. So a saving of say 15W. This would get a speed gain of about 0.5kph.

      However the aim with the current hull is to verify that we can predict performance with some degree of accuracy. An optimised longer thinner hull would do about 12kph with Greg's output but it would not be suitable for making an ocean going craft for testing ideas for a crossing boat.

      Greg is considering a reduction in rudder size but the gain is very small – probably 3W at best but it is easy to do.

      Rick W.

    • Buzz Powell on May 15, 2007

      Would it be legal during the 24-hour record attempt to use a small solar panel placed on the bow to trickle charge the onboard batteries of peripheral items like the DVD player and the iPod during daylight hours?

    • Alex on May 22, 2007

      Perhaps some people might baulk at the idea but do you actually need a "dirty water" bag? Couldn't you just errr pee over the side so to speak? After all fish, and little children, do it all the time and I doubt you'll be producing that much you'll pollute the lake.

    • Adventures of Greg on May 22, 2007

      Alex: It is the city of Calgary's drinking water. You are not allowed to swim in the reservoir, no motor boats, no inflatable boats, no batteries, no wind surfers.

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