Rick:
I assume you are using Gates
Polychain or HTD belt...... Looks to be about 1.5"....... I like
your large dia low speed prop.... it's about what I would have
gone for. I also like the way you designed the prop mounting so
it could be brought up easily... elegant! My guess is that this
system is 1x all the way through.... which I like also.... It just
makes sense in so many ways in terms of R-number range gearing
losses, tip losses, etc.
I assume that your prop has twist,
though it is not obvious......... Prop twist is an interesting
topic. It creates a "groove"......... a speed where it all comes
together....... above or below that speed it is not optimal.
I have zero interest in
competition, but the fall out from it is of significant value when
used intelligently, for real world applications.... the reduced
effort level and improved speed and distance for the effort
expended is of significant value. I bicycled 30 miles a day in HS
to school and back........ across town (my choice of schools). I
ran a Crescent 531 frame bicycle with sew up tires pumped to over
100 psi, toe traps, etc (late 60's tech)........ built my bike to
suit me and minimize effort. It was an economy effort by a budget
conscious boy using hard earned money, but I could hold my own
with anybody except the pro athletes.......... nor did I care.
I often rode 150 miles, or even 200 in a day on trips........ it
drove my folks crazy!
As I said before, there is
something that strongly appeals to me about rowing with a full
body system that brings legs, arms, and shoulders all into
play........... I was never a high RPM pedaler............. I was
a power pedaler, who used the faster gears......... Lots of power,
not lots of speed. I couldn't run around the block, but I could
carry a pack in the mountains 20+ miles in a day, where the
runners could not............ A different kind of horsepower.
H.W.
On 8/29/19 6:29 PM, Rick Willoughby
rickwill@bigpond.net.au [harryproa] wrote:
The linked video shows the folding prop I have developed for racing boats:
The curved shaft here is a carbon shaft that I was durability testing for a high performance boat. I normally use a high strength stainless I get the props made in China and sell for USD110. They are good for 100N thrust and intended for very easily driven boats. The propulsion system is compliant so can take heavy hits on logs and rocky shallows without suffering damage.
The video shows the pedal drive belt and gearbox:Any pedal drive frames I build now use belt drives. A number of the pedal drives I have designed for the R2AK are also using toothed belts.
I will go through the links. Hid Figre 4 in the article opn shapes does not consider flared sides. The lowest wetted surface 3-panel section has a 26 degree flare on the sides. However wave drag is a function of maximum beam squared so the lowest drag 3-panel hull has variable flare; more flare in the ends than in the middle. I use GODZILLA for hull optimisation. It is a function within Leo Lazauskas’s Michlet program and very powerful optimizing function. It produces reliable results that I have confirmed over many years of testing.
Rick
On 30 Aug 2019, at 1:26 am, StoneTool owly@ttc-cmc.net [harryproa] <harryproa@yahoogroups.com.au> wrote:
Rick:Check this article by Mike Waters out......... a PDF download: https://smalltridesign.com/pdfs/W17ProBoatOctNov2017.pdfBelow is a snip of a web page with a bunch of his articles if you are interested,
I was unable to determine from anything I saw, what the propulsion system for the HPV boat in one of your links was...... You can see the pedals, but not the propulsion system. Is it a screw or the fin system like the Hobie Mirage?? Or something else? Pedal power makes sense for a dinghy, though I like the full body workout oars, especially with a sliding seat gives. If I lived along a flat water river or lake, I would own a rowing shell.
H.W.
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Posted by: StoneTool <owly@ttc-cmc.net>
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