Jet Kayak RC components

[grindz145]

Almost ready, Just waiting on a shunt for the cycle analyst in the mail!!!

@hillhater: I was just wondering what it could do on that size of boat, I have only seen them used on small fishing boats and kayaks, good point though

The rule of thumb for gas engines, and displacement hulls (at least for sailboats) Is about 1 hp per 1000 lbs, to achieve hull-speed (for my boat that's 5.9 mph). This trolling motor is one of the largest made at 105 lb thrust, any many people use a 25lb thrust to 1hp rule of thumb as well. That would make the trolling motor equivalent to about 3-5 hp motor, even though it technically only uses about 1.4hp.

Another cool aspect of that, is if I use a regen controller, I can charge while sailing! For the casual sailor who doesn't do long distances, the electric motor would be all you need to get in and out of the harbor.

[mikebikerad]

Nice! Thanks for the info.

Here is an article about a sail boat with some thin film solar laminated onto the sail. Cool idea but it doesn't mention how many watts it produces or if it decreases the effectiveness of the sail.

http://www.celsias.com/article/polar-explorer-raises-worlds-first-solar-sail/

[grindz145]

Cool concept, and it might actually be worth it order-of-magnitude wise. But man, I don't want anything else increasing the cost of sails! Those things are pricey enough. A big panel over a bimini or rear rail would provide quite a bit, a few hundred watts could be worth it, plus regenerative sailing, that's the benefit I think.

[mikebikerad]

Here is a quick video of the kayak running off the Rotomax 50cc fully submerged. This is with a small 80 amp controller, Ill be trying ti with a 200 amp controller soon. I am still trying to get the RC Cycle Analyst dialed in perfectly so it currently doesn't have the most gentle throttle curve.

[grindz145]

I'm curious how that would hold up being completely immersed like that. I can't imagine terribly long. Outrunners are perfectly suited for electric boat motors though. That's essentially what the motor guide version is that I have.

[coldfusion594]

I'm curious how that would hold up being completely immersed like that. I can't imagine terribly long. Outrunners are perfectly suited for electric boat motors though. That's essentially what the motor guide version is that I have.

What if someone with a lot of resources finds a way to wirelessly send energy to the motors?!?
Kinda like a handsfree bluetooth except with battery packs and a motor

-Karl

[grindz145]

OK Mr. Tesla...

[mikebikerad]

I was tempted to seal up the motor so the copper wouldn't be submerged, but I think that it is better to leave it all open so moisture can get out easily, just like in drilled hub motors.

[mikebikerad]

And a picture of the rotomax motor when I was testing the small 80 amp controller so you can see the primitive construction using a yakima roof rack channel

[Bazaki]

I have seen a pedal system for kayak's, it is a very light system, what if we just install a RC motor on top instead of the pedals ?
This in combination with a Flyak should get speeds of 30 km/h with only a few hunderd watts.


http://www.youtube.com/watch?v=jh_Rhkej ... re=related


And see attachment

[mikebikerad]

That is a great idea! The Hobie mirage drives are surprisingly fast and just putting the motor on top would eliminate all the issues of submersion.

[Jeremy Harris]

That is a great idea! The Hobie mirage drives are surprisingly fast and just putting the motor on top would eliminate all the issues of submersion.

The Mirage drive is OK, not that efficient, about the same as oars or paddles, a fair bit less efficient than a propeller, but much more efficient than a water jet. A friend of mine, Tim O'Connor, converted his Mirage drive powered canoe to electric power for a race last year, using a cordless drill driving a high reduction ratio gearbox and a couple of cranks. Here's a video of him (scroll to about 6:36 to see him, the white open canoe in the foreground): http://www.youtube.com/watch?gl=GB&v=t82OL0YObw4 Tim's boat went pretty well, it probably cruised around the course at about 4 kts or more, with the drive pretty much lashed together and fed with at best a couple of hundred watts.

[mikebikerad]

Just had a nice email from someone here.....

http://solarbootverein.de/#solarboot

Awesome German solar boat racing series!! Anyone know if there is something like this in the states?

[mikebikerad]

I wish I would have found this company before getting my graupner jets. The jet 80 will be my next present to myself!!

http://www.mhz-powerboats.com/Antriebe/Jet/

[dirkdiggler]

Wouldn't it be easier/cheaper to use an old Jetski impeller setup?

[mikebikerad]

It would be cheaper. Are there any jets from small jet skis that are not to bulky?

[dirkdiggler]

I have no idea as to the size of these. I'd think about 4 inch by 16 or so. I was hoping to use one on a surfboard if I ever get around to it.
Here's an ebay listing:
http://www.ebay.com/itm/Kawasaki-Jet-Ski-650-SX-TS-SC-X2-Impeller-Pump-steering-nozzle-/251220585858?pt=Personal_Watercraft_Parts&hash=item3a7de9ed82&vxp=mtr
$75 is alot cheaper than 600 Euros.

[mikebikerad]

I bought a pump for a small sized jetski on Ebay when I was ordering the graupner jets for $60 with fouled up bearings. I chose not to use it because it was so bulky and the size of the impeller led me to believe I would need to use a 30+kw inrunner motor to reach any type of efficiency which would just make the boat sink. 600 euros is painful but they are the perfect size for fast boards and kayaks

[dirkdiggler]

I don't know if you have seen this video:
Looks like they made the jet themselves out of PVC pipe. I can't figure out the size of motor they were using an 8hp Leopard. The biggest size I see for Leopard motors is 5692.
This guy built a boat with a 500cc size pump, again don't know what motor he is using. He says he wants to go bigger on the pump size due to the motor handling it well:

[mikebikerad]

I commented on that jon boat video(thanks for showing it to me), will be interesting to see what he is running. It looks like he is not getting any where near full thrust out of the jet, maybe needs more RPM? but still sweet power for a little boat.

I got one of these http://www.hobbyking.com/hobbyking/stor ... duct=19111 and played with it in the bath tub hooked up direct to a 3'' boat prop and it created a monsoon on 2s! The RPM seem perfect but the cheap 20c Hobbyking cells I was using made the esc cut out after a few seconds. Fun stuff.

[Hillhater]

I got one of these http://www.hobbyking.com/hobbyking/stor ... duct=19111 and played with it in the bath tub hooked up direct to a 3'' boat prop and it created a monsoon on 2s! The RPM seem perfect but the cheap 20c Hobbyking cells I was using made the esc cut out after a few seconds. Fun stuff.

How do you figure it was the battery that made the ESC cut out ?..Low voltage ?
Or did the ESC overheat ?

[mikebikerad]

The 2s pack was sagging to around 5.9x volts when the prop was loading for a few seconds, causing the esc to think it was a low voltage situation. The esc was slightly over ambient temp because I only ran it for a few bursts.