Search found 55 matches

by bobkart
Dec 02 2021 4:35pm
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

We got out on the water a few days ago with the transom lowered one inch. At first it would still ventilate at top speed, then I trimmed the motor in five degrees and that pretty much cured it. It was windy and rough, as can be seen in this rear-facing video: https://www.dropbox.com/s/kmsuo94jgmygke...
by bobkart
Nov 26 2021 2:24pm
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

I'm all for going faster/further on the same power/energy. Unfortunately, my searches for aftermarket propellers for the ePropulsion Navy 6.0 Evo don't reveal any sources. Of course someone could measure the mounting pattern and integrate that into a new propeller design, but that someone would not ...
by bobkart
Nov 16 2021 9:28am
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

And try an even larger/higher pitch prop to see the difference. Unfortunately, there's only one other pitch of propeller available, and it's lower pitch, not higher. The control for the motor includes an instantaneous watts readout (and speed). I will definitely plot those two values at various wat...
by bobkart
Nov 15 2021 7:43pm
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

Hi again SlowCo! The motor comes with two propeller, differing mainly in pitch. I'm using the higher-pitch propeller, due to the pitch involved being more in line with my expected top speeds. The lower-pitch propeller has about 30% less pitch, so would likely only achieve around 10-11mph. I could se...
by bobkart
Nov 13 2021 10:41pm
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

The 6kW motor arrived last week, and we got out on the water with it today. It worked well; good power and speed. But we experienced ventilation (also referred to as cavitation) approaching top speed. Transom could be a bit lower. Also, ePropulsion makes an 'anticavitation plate', so that's another ...
by bobkart
Nov 02 2021 1:02am
Forum: Electric Watercraft
Topic: making a generator
Replies: 6
Views: 272

Re: making a generator

I've looked into a series-hybrid approach for my electric boat build. Here's what looks like a decent DC Generator that can be fueled by propane (LPG): https://dcautogen.com/product/v5-autogen-48v-dc-generator-charger/ Propane creates much less pollution than gasoline or diesel, and can be stored mo...
by bobkart
Nov 01 2021 2:35pm
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

Any day now on the 6kW motor. In the meantime, we got out on Lake Sammamish this last weekend.

https://www.youtube.com/watch?v=4aVHY3oM3pY
by bobkart
Oct 29 2021 12:49am
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

The good news is that these motors come with two propeller sizes (low and high pitch). At maximum propeller RPM, theoretical speeds for the two pitches involved come to 12.5 mph and nearly 16 mph. I understand that I'll likely not achieve that RPM, and that there will be some slip percentage. 10.x m...
by bobkart
Oct 26 2021 5:57pm
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

6kW motor shipped today . . . should arrive either Sunday or Monday.
by bobkart
Oct 22 2021 10:21pm
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

Great result :thumb: Now build a solar roof on top of it for extra range and charging during a trip. Yep, that's on my list. I estimate there's room for between 1kWp and 2kWp worth of panels. Using flexible panels, the added weight could be around 60 pounds (for 16x TP Solar 100Wp panels). That's b...
by bobkart
Oct 20 2021 8:48am
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

Got a smaller motor I had laying around installed (2.2kW Hangkai). Came as a tiller model so had to fabricate steering linkage and wire throttle/etc. for remote use. https://www.dropbox.com/s/586i59m154nuxu9/Electra-full.mp4 Seeing just over 7mph top speed, and would run for 4.5 hours at full power,...
by bobkart
Oct 12 2021 7:35pm
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

Order placed for ePropulsion Navy 6.0 Evo: https://www.epropulsion.com/navy/ I should see about 14mph top speed. With the 10kWh battery I have, should get 1.5 hours at that speed, with 10% battery capacity to spare. So 21 miles of range. At half power, I should see close to 10mph. So three hours of ...
by bobkart
Oct 01 2021 1:11am
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

It took six months to ship (because of the pandemic), but the boat should arrive this weekend.

https://www.rowingsolutions.com/
by bobkart
Apr 18 2021 12:47am
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

Thanks for joining the conversation, kerosene. I was hoping for more like 10mph from these hulls, but it looks like 6mph is it. So I'm back to the 12V trolling motor and will be trying the remote steering idea next (swivel seat to turn). Then possibly go to a three-hull version for two-person capaci...
by bobkart
Mar 27 2021 10:45pm
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

https://www.youtube.com/watch?v=sWwlXnG69yA Either my cellphone speedometer is off or the speed increase due to the more powerful motor was underwhelming. I only saw 10km/h, but it felt faster. Definitely too much weight at the rear, made worse by the high thrust below the waterline tipping the bow ...
by bobkart
Mar 23 2021 8:25pm
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

Thanks for the advice. I bought one after first hearing about that option (3-blade 8" x 6" pusher), but haven't tried installing it yet. The drilling-out part seems easy enough, but making the groove I'm less sure about. A file sounds like a good idea for that. I'd be interested to see a p...
by bobkart
Mar 22 2021 4:25pm
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

GOPR9016.JPG I'm top-balancing a dozen 40Ah LTO cells. The plan is to make an 11S battery from them, to approximate the voltage profile of an 8S LiFePO4 battery. Then I can combine this with half of my 48V-nominal LiFePO4 battery, and come in under the weight limit for two hulls (200 pounds per hul...
by bobkart
Mar 14 2021 3:07pm
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

Thanks for the link, SlowCo. I've seen that brand mentioned before, and Kipawa. I contacted Kipawa and they don't make a model for my motor. I may reach out to Small Town Bassin at some point, but now I'm lined up to try the 2.2kW motor. I have another half-dozen of the 40Ah cells coming, and can co...
by bobkart
Mar 13 2021 2:25am
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

https://youtu.be/7WQX1tzHJJw https://youtu.be/SU6iHd3dLsE Changes since the previous run include: - motor back to original rear-facing thrust - aluminum crossbars and knobs - quick-release deck pins - better seat I also tried some 40Ah LTO cells (5S). Seemed like less voltage than 4S LFP, so may try...
by bobkart
Feb 27 2021 10:48pm
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

Today went pretty close to how I expected it would. There were a couple surprises: - the boat sat lower in the water that I was hoping (basically to the black tape line) - the front-steer approach worked poorly Less surprising: the bow was heavy (as I was concerned it might have been). Control in th...
by bobkart
Feb 27 2021 1:25am
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

It turns out I didn't need the extra crosspieces, because when the deck is installed, the hull crosspieces are enough to prevent the excess deck plank deflection I was concerned about. So I'm at 117 pounds before motor/battery/seat/pilot. https://i.imgur.com/EO4P80d.jpg I turned the deck around so t...
by bobkart
Feb 26 2021 1:12am
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

Looking to head out on Saturday to a nearby small lake (nearby river is running too fast for comfort for a maiden voyage). https://i.imgur.com/vYRnuY4.jpg I'm going to start with the smaller motor though (that's the 2.2kW motor). https://i.imgur.com/fRz5VcZ.jpg Deck comes to 29 pounds so far, but I'...
by bobkart
Feb 21 2021 2:32am
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

I got a better scale and see a baseline weight of 35.23 kilograms or about 77.7 pounds. Picked up some Western Red Cedar and am playing with deck configurations. https://i.imgur.com/PaVBswT.jpg This is close to what I'll likely start with, but I need to make the transom wider, as I'm getting more fl...
by bobkart
Feb 16 2021 10:03pm
Forum: Electric Watercraft
Topic: Getting Into Electric Power Catamarans
Replies: 84
Views: 3956

Re: Getting Into Electric Power Catamarans

The knobs finally arrived today (weather delay), and I was able to get a baseline weight reading of between 80 and 81 pounds (just with a bathroom scale). So that 445-pound number I guessed at earlier is holding as the remaining capacity I have to work with.