For sale by original owner: 16' electric-powered pocket fantail launch designed by Stuart Reid of New Zealand and professionally built in 2010 in St. Augustine, Florida. Located near Jacksonville, Florida. $8,500. Home
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Hi everyone,
I swear its easier to weld up a contraption than it is to assemble photos and up load a "show and tell" presentation, but I did it...hope you see this without a hitch or glitch
I've built a big trolling motor...about 100lbs, will run my boat 5-6kts at 1650watts through a 36volt planetary geared-down motor from a floor sweeper machine that powers an 18inch X 18 pitch bronze prop. it rides in the rudder gussets of my RK21 day sailer/cabin sailboat.
I am a sculptor, so have a tig welder and scraps of copper/stainless/silicon bronze....everything is made of these non-corroding materials.
two wheel chair batteries..50AH @12v will run this boat 6mph for miles on just a straight connect....I have been running it on 48v through a pwm.controller
I get a lot of curious looks from all the fossil fuel burners on the lake....cruising with my family @ 5-6 kts is just fine, no hurry, no need to water ski, just blissing out cruising and fishing. might add a solar roof later this season
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My latest electric drive project is for a Cat27 (1981) that i picked up at auction real cheap-- $360. , mostly because it had no diesel engine left in it....PERFECT! I tried to pull dampener/flywheel off its 1 inch bronze shaft, but it wouldn't budge, so I removed prop and pulled prop shaft out into boat...might as well re-stuff the stuffing box and buff the old bronze shaft up eh?. So I had a 8-10hp electric motor that i decided to gear down to about 1000rpm for cruising.
The power-shaft of my build was an old Chevy axle which i cut down to 24", I mounted it inbetween off -the-shelf pillow block bearings and spun it via an old washing machine motor and belt, then took a 5 inch grinder to it as it whirled round at 1700 rpm, I worked the metal down like I was sanding a spindle on a wood lathe. The out of balance shaft was soon a gleaming, balanced shaft with a flat faced flange and inset to recieve dampener...the thing looked like it came fro a machine shop! I scored a line at exactly 3.25 inches, and with dividers marked off quadrants to get the location of the 4 bolt pattern. I struck them with a center punch and drill themon my drill press and ...perfect! they match for a smooth balanced bolt up
The motor is held on a tripod support with tighteners to tension and adjust the roller chain side-to-side. I used the old diesel motor mount isolaters to carry the assembly and slide it in for a bolt up.
"EZ - DC" (that's the name of my boat)
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Just read about this manufacturing breakthrough that purports to cut in
half the cost of producing lithiun ion cells.
From what I understood, it allows the electrolyte layers to be thicker
and manufactured in a continuous roll and avoid drying times. I
especially like the $0.10/wh projection by the year 2020. At that cost,
lithium will be the best thing going by any metric for electricity
storage in boats.
My existing 5kwh pack cost just about $2500, including BMS and battery
packaging (straps, buss bars, etc). Others here have also said under
$0.50/wh is achievable. To bring the cell cost down to the $0.15-$0.20
at low-volume retail level would be just absolutely amazing. On a
per-usable-ah level, that is on par with wet-lead in price even
including a basic BMS, but still has all the volume and weight
advantages of lithium.
http://newsoffice.mit.edu/2015/manufacturing-lithium-ion-battery-half-cost-0623
--
Jason Taylor
--
S/V Fugu
1978 Beneteau First 30
Electroprop PM-20
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Just read about this manufacturing breakthrough that purports to cut in
half the cost of producing lithiun ion cells.
From what I understood, it allows the electrolyte layers to be thicker
and manufactured in a continuous roll and avoid drying times. I
especially like the $0.10/wh projection by the year 2020. At that cost,
lithium will be the best thing going by any metric for electricity
storage in boats.
My existing 5kwh pack cost just about $2500, including BMS and battery
packaging (straps, buss bars, etc). Others here have also said under
$0.50/wh is achievable. To bring the cell cost down to the $0.15-$0.20
at low-volume retail level would be just absolutely amazing. On a
per-usable-ah level, that is on par with wet-lead in price even
including a basic BMS, but still has all the volume and weight
advantages of lithium.
http://newsoffice.mit.edu/2015/manufacturing-lithium-ion-battery-half-cost-0623
--
Jason Taylor
--
S/V Fugu
1978 Beneteau First 30
Electroprop PM-20
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Tom,
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I have two Alltrax controllers. One is a AXE series in a 15' launch running @24V. The other is an SPM series, also at 24V in a small launch.
I'd recommend the SPM, it has an integral heatsink and fan, cable connections are better positioned, and the programming cabling is simpler.
You'll pay about $250 for it.
Great products, made in the USA.
-Tom (who has no monetary interest in Alltrax, just a happy owner.
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Excellent question.
I have no idea, but perhaps someone who repairs electric forklifts, os sells them, might point you to a source for (second hand) controllers .. ?
My experiences with industrial stuff is that its either real cheap, or real expensive.
Ie old stuff not in vigue is real cheap, and new stuff sold by current installers / repairers is ridiculously overpriced.
Im really curious about the forklift-level controllers prices myself.
Please let us know if you solve this, and at what cost..
Curious minds want to know..
I think the motor came from a forklift, so there must be some manufacturer out there making controllers for this motor, but I have a hard time wading through all the info online. The only criteria is being able to reverse the motor.
Any recommendations on a good controller for this motor?
Thanks!
-- -hanermo (cnc designs)
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Great post !
I think your expectations are pretty much spot on.
Hope it works out.
Well done !
I estimate 2000 watts-2500 watts will get me to 80% hull speed, (like 5 knots). but we will see in trials in the coming weeks.
just want to say hey to another sailboat converter...you can do it, gear down your electric motor to run prop @ 1000 rpm. , use voltage 12- 24-, 36-, 48v to choose your speed in a slow-low-medium-high switch....you will save so much more over a high amperage motor controller.
I'm using 50 AH wheelchair batteries AGM type, 25 lbs apiece, Under $90 ea delivered for power. My 21 foot electric sail boat (rk21) ran over 6 miles at 1600 watts/5knots on mostly just two battteries more than adequate for you Baltimore harbor needs
go electric!!!
-- -hanermo (cnc designs)
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Hi all,
About to start an electric refit of a Tartan 27 sailboat. I have a friend with a Advanced DC K91-4003 motor - series wound brushed DC motor who will make me a deal on it. It's got plenty of power, and I have no problem with brushes (it would take me 20 seasons to wear out a set - I sail more than motor), but I'm having a hard time finding a suitable controller. I think the motor came from a forklift, so there must be some manufacturer out there making controllers for this motor, but I have a hard time wading through all the info online. The only criteria is being able to reverse the motor.
Any recommendations on a good controller for this motor?
Thanks!
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Or, you could just take the damn thing to a prop shoperic SV MeanderHave you tried measuring the voltage to the motor from the kelley controller when it runs at or close to 40A?
I'm not sure how a regular digital multimeter would handle the PWM chopped waveform. Would it read max voltage experience (ie: 24V) or would it average out? Perhaps an analog gauge would work a little better in this case.
Anyway, the voltage from the kelley controller to the motor will tell you what duty-cycle the PWM is working at and therefore the effective voltage being sent to the motor at max amp-draw.
If you have the rpm/volt constant for your motor, you can then obtain RPM and coupled with boat speed in knots you can determine the effective pitch of the propeller (assuming a perfect prop with zero loss). AT that point, it's anybody's guess as to how efficient the Kipawa props are. Personally, I never assume more than 50% efficiency. So double that number for the resulting pitch.
To recap:
1) get rpm/volt constant of your motor.
2) Determine effective volts from controller to motor when operating at 40A
3) get speed through water reading in kts, or use GPS speed averaged over two marekd-distance runs in opposite directions.
4) calculate!
a) (speed in kts) * 72913 / 60 <== This converts speed from kts to inches per hour, divide by 60 to convert to inches per minute.
b) (motor constant rpm/v) * (voltage from controller to motor) This gives motor RPM value
c) divide a) by b) to get real inches advanced per revolution.
d) divide by 50% efficiency (divide by 0.5 or just multiply by 2) to get a good estimate of prop pitch.
This is an exercise that can be done when you know the real pitch but want to know the efficiency at various speeds. A good thing to know for your boat, in my opinion. It will allow to objectively quantify improvements to your drive system over time.
Cheers,
/Jason
On Jun 18, 2015, at 5:09 PM, gwest@... [electricboats] wrote:
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> I have a Minn Kota Endura 40 turning a 314 Kipawa prop on a small 16' launch. I have had that configuration for probably five years now. The motor is connected to a 24V Kelly controller (and two AGM batteries in series) and the controller is programed to limit 40A to the motor so the motor wouldn't burn out. The prop spins faster and moves the boat significantly faster than the normal Minn Kota at 12V, and the controller lets the motor on my boat run at 18 or 19V usually before hitting 40A. On a lighter boat, it would probably let is spin faster. (As I understand the Minn Kota names, the 40 is usually designed as pounds of thrust, but it also seems to represent the maximum amps to the motor before it burns up.)
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> When I described this on this listserv a few years ago, I remember that a few people seemed to think it was a really bad idea and that the motor wasn't desi gned for higher volts and higher speeds. But it seems to run faster fine as long as I limit the amps. And if I have to replace a cheap $130 motor every few years, it's not the end of the world. (As an aside, I have the Kipawa on the boat under protest, since I really hate that the company will not disclose any information at all about the prop specs except that it "increases speed." I certainly asked, even nicely at first, for information about the prop, but to no avail.)
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