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Re: [EVDL] Wooden Electric Cat and MC

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Re: [EVDL] Wooden Electric Cat and MC

Hi Mark and All,

I'm still around but some days are better
than others. Went downhill this spring/ early summer but
doing better now.

Glad to see the Ecat is being eff. I've
been thinking about it more and have a better design that
would work better for you with more weight carrying ability,
better seating, etc, and possibly your inboard twin E-tek
motors to solve the motor problems and increase speed, eff,
lower amps.

If you like and can come down this fall
we could build another, better cat in 4-5 days with you
doing finish/painting/etc, work at home. I'd do my part for
free with you just buying materials and doing much of the
labor as I can't do much anymore. But it's an easier, faster
design to build so could finish all the structural parts

On a wooden boat one really shouldn't use
foam and have very good ventilation as those problems that
you had would show up. I'd use yellow pine plywood too which
has better, longer life though grainier surface. Very
resistant to dry rot though and what I built the Ewoody from
which lasted 10 yrs outdoors, no garage/carport in rainy

When I can, work 10-15 minutes, recover,
I'm building an aero cabin 2wh MC EV from a KZ 750
suspension with a wood/epoxy body/frame from parts I have
lying around including from the old E Woody for the motor. I
found some really beautiful grained ply for the body so
should be a show stopper.

I talked about someone should build one
so I'm doing it. If it works out I'll sell my EV trike and
use that to build another to sell. If it doesn't I'll change
it into a EV trike with a golf cart transaxle for a 45mph
one. But rather have the 80mph 2 wheel version.

Cost is really low as little money but
already had the MC, $300 I bought a yr ago, the EV drive is
mostly used or other parts lying around and 4-6 12v/72lb
cell phone tower take out batteries, $18 each. All together
I'll have about $700 in it.

Jerry Dycus

----- Original Message Follows -----
From: Mark Hanson <[email protected]>
To: <[email protected]>
Subject: [EVDL] Wooden Electric Cat
Date: Mon, 30 Aug 2010 10:47:10 -0400

>I also have a wooden boat, a Cat built by Jerry Dycus
>(havn't heard from Jerry, is he ok?) which from what I've
>measured is about 28% more efficient (V hull) than a O or U
>shaped hull pontoon or displacement boat. My max speed 1.5
>x sqr-root of 18' = 7mph which is about it with 16ea 200ah
>(actually 100ah with 32 60A fuses buddy pairs) of
>ThunderSky 50V $5k worth of batts, 200lbs total. The cat
>weighs 1700 lbs. I hasd solar panels on top but due to the
>displacement/HP formula in Dave Geer's prop handbook, I
>found it was more efficient to orient them on my house and
>plug into the solar panels when I got home from the lake
>(saved 127 lbs). Weight is the enemy especially on a cat
>for efficiency, HP, displacement.
>I'm presently drawing 80A at 50V about 4kw or 4hp with
>efficiencies factored in on the E-Tek PM motor with my
>homebuilt controller & charger. The uWave oven transformer
>charger secondary was tweaked to allow 1/2 amp final taper
>at EVcomponents Dave Kois recommendation of 3.8VPC for
>Thunder Sky LiFePO4 batts. The only problem I see with the
>balancers as previously pointed out, is if one dies, that
>cell can either jump up in voltage, frying it or a scwartz
>if the fet gets stuck on. Fortunately that hasn't happened
>but secondary monitoring would be good to add. Keeping
>final taper charge current low at 61V (final at 16 x 3.8V)
>1/2 amp keeps things subdued if a balancer goes bonkers. I
>also have a battery scanner while driving so I can see if
>any cell drops below 2V. So far knowing 15 mile range with
>a Garmin GPS, I havn't gone below 3.0Vpc even after this
>week-end of lake bar hopping, from the Marina with live
>bands, to an sandy island with ice cream, to a tiki bar
>(with !
> a Mississippi style paddle-boat), then a beach area with
>slides, dinner at a China restaurant & floating dock
>putt-putt golf and back to the put in 10am - 8pm on SML.
>Sunday we went on lake MooMaw wilderness lake, lotsa
>wildlife but the 1.5khz eeeee scared them away, so usually
>just ron in bypass (may bump up switching freq or change
>BTW, I tried Minnkota trolling motors but reliability for
>electric drive wasn't that good (for one season) but was
>improved with copper impregnated brushes. The E-Tek Briggs
>& Stratton 8x8" prop has been very reliable about $1.5k and
>was cheaper than the Ray $5k 48V with a 12.5 diam x 10
>pitch prop (Curtis & GE GC motor). I'm thinking about
>trying a used outboard with the Etek-RT 2k rpm at 48V with
>a 2:1 reduction. I tried the inboard drive with a 16x16"
>prop but it wasn't more efficient despite the claims I
>found in boat books I also measured 80A at 7mph so i took
>it off & saved the weight. A larger slower turning prop
>would be quieter (like the Ray).
>Have a renewable energy day,
>Mark in Roanoke, VA
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