| ||||
|
#1
| ||||
| ||||
| Hybrid human/electric 2-person catamaran ... and now for something completely different? This may be silly and completely unworkable, in which case I apologize for the waste of time, and hope you at least find it a little amusing... Some here may know I've been trying to work up plans for a zero-emissions ferryboat for harbour service... and I've been trying to understand a bit about electric propulsion. On a completely different tack, I would also, someday, like to have or build another pulling boat for myself, suitable for guest and picnic... Anyway, I have been reviewing some of the message traffic (1999 to present) among the good folk over at the Human Powered Boats Mailing List - much of their discussion involves highly efficient hull shapes and propulsion systems, and many of the posters are obviously highly skilled with many years of experience. They have me thinking now, about chucking the old oars, and going pedal/prop. But because I am so ignorant about so much of this, I get to think "outside the box" <grin>... probably way, way, too far outside the box, but anyway. Here's my last post to the HPV-Boats people (via the eBoaters). Go ahead, it's OK if you have a good laugh... From: "lockhughes" <felixkc123@h...> Date: Sat Aug 10, 2002 7:29 pm Subject: [hpv-boats] Air vs Water props, cadence,transmission efficiencies,faq, etc etc! Yeooooo eboat folk... call me crazy, everybody else does. I've been reading up, postings from the HUMAN POWERED BOAT universe... Can you think of anyone more interested in hulls and propulsion efficiencies? Here's my post to their Mailing List: To: hpv-boats@i... Two weeks in the lab can save an hour at the library. Anon Thanks to Bob Stuart for this little tag line that I stumbled across. I've been reading the HPB-boats archives for the last (ohmygawd) 5hrs... started back in 1999 and I'm only up to August 2000 so far! ARGHHH! I started out trying to make notes about some of the *excellent* posts I have been reading. I wanted to start this msg by posting some thank yous - but there were just too many - so, thank you ALL, who have been contributing to the list over the years. I'm *supposed* to be working on an electric ferryboat, but you guys have got me completely off on another tack at the moment - curse you all, and THANK YOU ALL, again <smile> I have an idea (now) for a hybrid HPVessel for two persons, which I hope is not OT here, because I will try and address some of the design aspects you good folk have been considering - stuff like cadence and transmission losses and weeds and ... I see air props have been verbotten at events. I understand concerns about safety. Other than safety, what other concerns might there be, considering an air prop vs water? As a long-time sailor, I am aware of parasitic drag in rigging and topsides,etc., but wouldn't this drag (air props, *cages*, support structure) in the air be less than the drag of rudder and struts, etc in the water, because of the different densities of the two mediums? I'm guessing too though, that props in the water are more efficient, because of that same higher density, of water? You see, I like that Decavitator!... and yes, I know the derivation of the boats name! I wonder if the safety concerns and bans would explain the lack of apparent interest in this List, or are there other reasons? What if the air prop was smaller, and there were two (or more?) of them, something like this: http://www.marlec.co.uk/products/prods/rut503.htm Don't know if all can see that - it's a wind generator with a smallish propellor with a ring at the prop tips. I have read a *lot* of msgs all about problems with rudder/strut/seal/propellor designs and practical considerations. If everyone were using air props, I guess there would be a different set of problems to face!!! About cadence, and transmission losses... here's my thought: I'd like *my* HPV boat to have an electric dynamo connected to electric motors driving the air props - two props at least. You pedal the dynamo and the energy is transmitted by wires to the motor. Not by u-joints or shafts or chains. Catamaran configuration. 2 persons, plus picnic. drink holders. Recumbent, so it's easier to reach stuff like picnic and drinks... and perhaps to reduce a little windage. My objective is not some speed record... It's comfort and distance. Perhaps a 5-6kt cruising speed, with possible bursts to 10K range in frisky mode. The electric motors and dynamos I'm talking about here are one and the same. You spin the motor and it produces electricity. I've have been trying to educate myself a bit lately about electric motors. Today we have available rare-earth, permanent magnets mounted on a rotor, inside wire windings. These little (and big) motor/dynamos have ONE moving part, and are claiming efficiencies of over 90%. I can buy ones off the shelf today which will run just fine, fully submerged. So for my little HP cat, I'm guessing an efficiency of 81% between the pedals and the prop? I'd introduce bicycle gears that I can shift, so there's some more loss there too... But otherwise, it'd be an almost solid state propulsion system? No shaft seals, u-joins, gear boxes. ... and no rudder. With a little electronics, I would steer the boat by changing the speeds of the props. These little electric motors will spin in *reverse*, if the current is reversed. So now, I'm backing up, and turning within a boats length if I wish, just by twiddling the joystick - yeah, I'm steering and reversing by joystick. With this configuration, the weedy lagoons around here would not be so problematic. Now I fear I'm getting a little offtopic so *snip* here if you think so... You guys bring up cadence. And how two persons need to be "sync'ed", or - de-coupled, if they're of different strengths (or temperments <grin>) So at this point, I introduce a little bit more electronics, and a battery. If the two pedalers are driving separate dynamos, then they are free to pedal at whatever speed they wish. If the pedaling isn't smooth, doesn't matter, `cause the electric smooth out the power by the time it gets to the prop. If the plan is to go for a leisurely cruise, the one pedaler or both can still pedal at frisky speed - and STORE their power for later, in the battery. In picnicing mode - boats pulled up on the shore - if there's some wind, the props turn into wind generators, and STORE wind energy. Tired on the water and taking a break from pedaling? Props spin in the wind again. Anyway. I'll stop here. I would appreciate any feedback, very much!!! I'm probably wildly over or under estimating some simple fundamental law of physics or the state of current technology <pun intended>... I was *supposed* to be an engineer at one point. Went to University, but discovered I couldn't drink enough to ever succeed as an engineer <smile> Regards, and thanks, one more time Laughlin Hughes http://groups.yahoo.com/group/QCYCTender/ [end of my post to the HPV-Boat folks] EBoaters? Any thoughts? am I crazy? by the way, if you read over their posts for the last few years, you will find TONS, and I mean TONS, of FASCINATING STUFF, about hull design and construction, rudders and props, etc etc. as it relates to small and highly efficient boats, by a lot of VERY KNOWLEDGEABLE PEOPLE!!! http://www.ihpva.org/pipermail/hpv-boats/ Lock ps... If you're curious about the reference to "Decavitator", check this out: http://lancet.mit.edu/decavitator/ and don't overlook the videos, like this: http://lancet.mit.edu/decavitator/vi...Run.better.mpg |
|
#2
| ||||
| ||||
| Lock; Be careful of manufacturers efficiency claims. Efficiencies of "over 90%" are typically at optimum conditions, full load, low temperatures, ... Your results may vary. Before you get too far along, you might want to verify that you can actually achieve these results at the speeds that you intend to operate and without a cooling with liquid nitrogen. ![]() Cheers; Mike Schooley
__________________ Designing "Portager" a transportable passagemaker |
|
#3
| ||||
| ||||
| Quote:
Trying to read up on (air) props at present. I would be looking (eventually) for motor/dynamos optimized for the rpms,thrust,etc. I would need - might end up winding my own or commissioning something (LRK's?) Have the plans (and a cheap source for rare-earth PMs) for a d-i-y Savonious rotor wind gen, which sorta ties in anyway. Boat specs look like this todate: 200lb boat, approx.10ft. beam x 18ft lgth. (including 2 dynamos, two motors, four batts and picnic!), 300lb crew, so 500lb. all up, and can be disassembled for storage. Twin, 5ft. props port and starboard, at the stern. Beams and supports, windsurf carbon spars. (Debating bow or stern for the props - bow would be cleaner air, and might be nicer on hot days, but harder to light cigarettes <grin>) See my msg to Ted for more odd ideas re hull construction: http://boatdesign.net/forums/showthr...=&threadid=784 Cheers L ps Quote:
|
|
#4
| ||||
| ||||
| I believe I may already have my drivetrain: (stolen from the Yahoo Group "Power-Assist") Quote:
motors - I have enough bicycle parts to make the test buggy. Cheers Lock |
|
#5
| |||
| |||
| You mentioned using Bicycle gears? Do you mean like Deraileur gears? Not sure I can see the point of that. gears on bikes are really only for hills, to handle large differences in speed (Uphill vs down hill) In the water you obviously wont have any hills, and the difference in speed between cruising and flat out is only double at most. I would have thought that you should just set up a ratio that works comfortably at about 60-80 rpm for the pedaler. Anyone any other ideas on this?
__________________ Mat Newland |
|
#6
| ||||
| ||||
| Hi Mat Quote:
Quote:
I am, however, tapping about using *air* props, not a water prop. So I was *guessing* that the speed range of the props would be much, much greater than a water prop? Like... 860 times as great roughly? I'd love to be able to get rid of any gears, really. Lock |
|
#7
| ||||
| ||||
| Just a couple more links for this thread? Here's a commercial hybrid human/electric pedal/paddle boat (water paddle wheel rather than a water or air prop): http://www.2californiablonds.com/energydeluxepedal.htm and here's a little video of a (semi-?) commercial (?) pedal-powered one person catamaran with an air prop: http://www.angelfire.com/trek/boat/XTREK3.WMV as I understand the scuttlebutt, the maker sold off a limited production and is "negotiating with investors", last heard of... Lock |
|
#8
| ||||
| ||||
| Hey - here's an air prop electric propulsion system that takes this one-man vehicle to over 30kts at a sprint (on land). Spotted at the National Electric Drag Racing Assoc's "Nationals" event, yesterday: http://alan.batie.org/photos/nikon/020901_nedra/ Will find/tap with this gentleman, find out about rpms, etc etc. Looks like 4 batts in the stern. Lock |
|
#9
| ||||
| ||||
| I just wanted to use the pic to illustrate the little "test-bench" I want to play with on deserted island roads this spring... For the record, re the "craft" in the pic: It's a "Wind Wagon" by Bill Bruder. Some more details: He hit a speed of 39.17mph on Monday. Had to "throttle back" at 39+ `cause his frontend was going airborne. (A record speed though, for Bill.) It has a 62" ultra lite prop built by IVO prop. 36volt golfcart motor running at 48V but "capable of more". The current motor is series wound. About 2500 RPMs The rig dry weighs 247lbs. plus Bill. 4 batts, 48 V NAPA Orbital Deep Cycle Marine He did three runs down the track and about 30 min. of himself and others driving it plus cooling people off during photo shoot. This was on one charge. Bill figures at 3 to 6 mph he can most likely go two hours on one charge - but he has never tried a distance run (!) He says it runs well at lower rpms also. Cheers Lock |
|
#10
| ||||
| ||||
| Given up on water props... Here's another air prop boat (hope, at least, some here find this a little amusing): http://www.tricrides.com/flyboat.htm cheers Lock http://groups.yahoo.com/group/QCYCTender/ |
|
#11
| |||
| |||
| I saw one of those operating in Sardinia I think- it was way cool and flew very well! |
|
#12
| ||||
| ||||
| *BUMP* Ahoy all. Long time since alongside here. Just wished to add/update this thread... from 2002. Can't say us humans have evolved much in this time, but battery-electrics vehicles and vessels sure have. Can you say "LiFePO4"? <smile> Anywhoo, the subject is human-electric hybrids and air props for boats... OK, electrics, but with a human assist... so, on the electrics side of things: As the internet moves to audio-visual, more of the content is video, so here are a couple of videos that illustrate what folks are up to w/electric air props: Two videos of a "Razeebuss" in action: http://paraglidetv.com/video/paramot...o-moteur/index http://paraglidetv.com/video/paramot...ircrafts/index Hey, if you sail, I'm w/you. These things sound like food processors! But in flight they have to worry `bout chopping lines and legs... On the water, we can afford larger/slower/quieter props. There is a yahoo group where these bleeding edge fliers hang out: http://groups.yahoo.com/group/electricPPG/ So, while I am embroiled these days with lubbers that don't understand what personal electric vehicles are about, I haven't forgotten the really important parts of the world (the wet bits...) Fair Winds and Following Seas Lock Hughes human-electric hybrid |
|
#13
| ||||
| ||||
| *bump*
__________________ human-electric hybrid |
![]() |
| Thread Tools | Search this Thread |
| Display Modes | |
| |
Similar Threads | ||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| Building a Catamaran - Costs? | Friday | Boatbuilding | 46 | 03-30-2009 09:12 PM |
| TP52s | mighetto | Sailboats | 2052 | 09-06-2007 11:46 AM |
| Join in a Co-operative Catamaran Build Venture! | Neven | Marketplace | 0 | 12-17-2004 02:20 AM |
| 37' Racing Catamaran Hull/Deck Mold set | Mason Clifford | Boat Molds | 4 | 10-27-2004 10:04 PM |
| Electric motor revolutionizes catamaran sailing | Jason Stevens | Motorsailers | 0 | 05-11-2004 09:10 AM |