[hpv-boats] Dennis Adcock - New Pedal Boat

[Rick Willoughby]

Dennis
I would have expected better than 6.8kph average.  8kph should be  
easy and 9kph possible for that length.  The slip is very high  
indicating the drag must be still quite high. I wonder how much the  
transom is dragging.  Filming a short video of the wake can be  
instructive or watching someone of similar weight in the boat.

Also what do you mean by "simple" GPS?

The 380mm prop I have on the V14 hull has about 3% slip.  The 520mm  
on the V15 is just over 1% - not really measurable but that is  
calculated.

Mike Lampi has started building the 6m version of my V15 design.  He  
is using 4mm ply that will be finished with glass cloth.  The ply was  
machine cut so saves a lot of work making and cutting panels.  He is  
updating his blog on the project:
http://hpb-er.blogspot.com/

I have been pushing the V15 boat to see how the new box would hold  
up.  I broke it last week end.  It failed at the torque level Mitrpak  
advised, which translated to around 350W on the boat.  It was not the  
shear pin that failed but rather the output shaft where it has a  
shoulder to support the small gear.  The ID of the gear is only 8mm  
so it is not unexpected when I back calculate.  This weekend I will  
start doing some long distance testing at sustainable power of 120 to  
130W to see how it all holds together.  That gets the boat between 9  
and 10kph in the current set up with outriggers set a bit low for my  
weight.  Their height can be adjusted but not easily.


If you can email me a drawing of the hull or photos showing the shape  
I can do some drag predictions for you.

Rick Willoughby


Re: Dennis Adcock - New Pedal Boat

Hi Rick
My new pedal boat "FAST 3" is now great at wave  hanging on the wake of
passing river pleasure boats.
The following mods. have been undertaken;
1.     2 off ball bearing races fitted to prop strutt.
2.     New flat bottomed out riggers set to be just clear of the  
water have
greatly improved the stability.
3.      Simple GPS fitted, but indicates very slow disappointing speed
4.    Prop calibrated, indicates 20% slipbased on pitch helix with no
allowance for angle of attack
5    Peak speed momentery 12kph average 6.8 kph  I think that my cat is
faster and will try the GPS on this.
6.    Rudder still to be sorted after many attemps.
7.     Folding prop is working well shedding weed, but failed after I  
hit a
rock as it jammed with one blade shut.

Your sisters boat looks good, with a good turn of speed for a boat of  
that
length.

Dennis