Alpha Gary! Finally got the other Tri launched. Check out latest video. Tried texting you but maybe you have different number now. Hope you are well and are able to get back on the water in some capacity around Sonoma.
With the much, much larger waters at such close proximity, do you have any plans to attempt Hanalei Bay, or outside? Maybe a ride down to Hanakapiai? I've done it on my NACRA 5.2 under sail. Its not exactly low stress, but the up wind leg back to Hanalei is do able. Your 'conversion is very interesting. I'd love to have a look. I'm considering a gasoline conversion to one of my NACRA's. I sail out of Kalapaki, so when re entering Nawiliwili with a following sea, you have to have more speed than the swell to avoid a broach. Will your electric manage it?
I built it mainly with for our rivers and winter boating season as I sail other boats in the Summer, but I take it out in the Bay all the time (when I can get out the river which is blocked at the moment) and have used it as my tender to get to my Trimaran during mooring season. I designed a Crab Claw Lateen sail rig for it with plans to do a Hanakapiai sail downwind motor back trip someday, but that was before I started building my 30’ version for ocean use. I’ve surfed bumps back in to the Bay from the bowl and the river can often be challenging when you have swell behind and strong current flowing out the river when the channel is narrow and you are trying to motor back up. I even sail my Hobie Wave out the river and back up to the ramp, so I know what you are concerned about. One advantage of this boat is the low CG and shifted CE since it doesn’t have a mast rig, and it weighs a lot more, so it tends to track better and is less likely to broach when picked up by swell. But, the motors are only so strong and props only so big and I use differential thrust to steer (no tiller or rudder) so for Kalapaki you would prob want more power and to retain the use of rudders/boards. If you go ICE with a Nacra, I would mount a 6HP. The 4/5/6 outboard legs give the best power to weight for something like a beach cat conversion. And make sure the leg is long enough to keep the prop from cavitating in swell. And as I always tell anyone looking to convert a beach cat -be mindful of weight and the placement of it. Hobie Getaways aren’t the lightest most high performance beach cats, but the rotomolded plastic hulls and their shape offer a tremendous amount of displacement thanks to their volume which provides capacity of 1000lbs. This is why I chose it as my foundation and why I was able to incorporate so much into it. Even then, I still used lightweight materials and designed a number of the systems to perform multiple functions. If you look at my other videos you can see how it rides out in the Bay and variations of features I have incorporated over the years like running with a camper shell for camping, the sail rig, etc..
Hi, I have seen in your previous video, you use caroute brushless motors. I'm also working on a similar boat. I wonder whether you use propellers spinning in the same direction(either cw or ccw) or have you found cw and ccw propellers?
I assume you are asking in relation to prop walk/torque steer, or perhaps efficiency? I have tried all kinds of combinations, and at this scale is isn’t an issue. My current props are modified Torqeedo. Since they are CCW the motors are run in reverse for forward propulsion. One noticeable affect of running a large diameter high pitch 2-blade on a light displacement boat like this is that you can feel the blades biting water at slow speeds and you lose some low speed maneuverability an will experience more cavitation when quickly reversing from forward versus the smaller diameter low pitch factory 3-blade.
@@shan7511 The props are the same rotation. Prop walk is more of concern when you have a displacement hull that needs to get on plane, and the props start biting water from one side causing the stern to walk. And torque steer is a mute point with my boat since I use the independent thrust of each motor to steer, which means I essentially use torque steer to steer. Having the motors well spread apart helps to ensure one isn’t causing the other to air-ate. If you had them close together running same rotation props, one could bite clean water while the other disturbed water which might cause issues.
@@kauaislash5 My boat is an autonomous catamaran skid steering, 18ft×9ft and weighs around 1500kg including payload. I have 2 sets of thrusters which can power the boat but steering is sluggish. So I'm trying to upgrade the motors to caroute. Which torqueedo propeller model have you modified and used?
@@shan7511 That’s pretty heavy. You would want to stick to smaller 3 blade (stock) props which are designed to propel and maneuver gear laden fishing boats. The props I use are too aggressive and would overload the motors trying to push that much weight. Not sure if by sluggish you are describing propulsion or maneuverability, but higher thrust and most especially lithium batteries will help with responsiveness in both departments. If you do end up switching to Caroute motors and are using them in a salt water environment, I recommend either disassembling them and greasing the main housing O-rings, or coating the entire motor housings in something like Plasti-Dip. With the exception of the big brand name outboard/drive manufacturers, the finish on the majority smaller name brand manufacturers just doesn’t hold up well over time. If the O-rings are sealing to a surface that is coated and the coating lifts, you lose your seal and will get water ingress in which case you are better off having a raw machined aluminum surface protected with grease. This is common practice in underwater connections. I also recommend while you have the motors apart, that you coat the housing bolts with Tef-Gel to combat dissimilar corrosion between the stainless and aluminum which will only speed up the possibility of finish lift under the sealing surface. If you don’t coat the bolts, you will have a very hard time removing them down the line if you find you need to inspect or service the motors as they will seize in the housing cap. I have recommended to Caroute that they do both, but don’t know if they have adopted the practices yet during assembly.
I'm just building a similar craft to yours (4.3m Paper Tiger hulls) and was very impressed with your engine mounts. Could I ask why didn't you just mount them on the aft cross beam just inside the hulls? Is there anything you would change about the battery and solar panel system? Thank you for the videos. John
A few reasons for my mounting choice. Outboards/props work better behind a transom/hull, and I use differential thrust to maneuver the boat (no tiller or rudder) so having the motors spaced as far apart and back as possible and just behind their respective hulls not only makes for amazing steering response, but also increases efficiency which is the name of the game with a small boat with limited displacement, surface area for solar, battery storage, etc.. with regard to range, speed, and carrying capacity. And the oversized anti-cavitation plates also act like stern extensions, so not only do they guard the props and keep the props from sucking air, but they increase waterline length and provide stern lift, and the longer a hull is, the faster its theoretical max hull speed. In my case, it allows for better top speeds at less power draw as they help to reduce wetted surface area while allowing the props to spin close to the waterline. Those are the major reasons. I also liked the challenge of designing a bolt on system that used the stock rudder gudgeon mounts since it’s a plastic boat and extra holes should always be avoided. On that note, building a boat like this starts with the hulls. They will dictate the rest of the systems. I chose the Hobie Getaway hulls because they have a bunch of volume and can float 1000lbs which allowed me to add all the necessary systems without it turning into a Submarine. So in your case, the low volume and short hulls of the PT will be your biggest design constraint. Weight adds up quickly. You’ll need to be very mindful of placement of systems to keep the boat well balanced, and use lightweight materials wherever possible. Battery/Solar wise, it all depends on your intended use. I designed for afternoon trips to destinations where I drop anchor and the bank recovers quickly, and I can cruise 5MPH on Sun only, but I have been modifying for higher top speeds and efficiency and will be building more powerful batteries soon and likely adding a few extra panels to offset the extra power draw. After that, I think I will have squeezed the most I can out of these hulls while still having a safe and reliable well balanced boat that is capable of doing everything I need it to do. When it comes to boat design, everything is a trade off. I always recommend identifying the most important attributes and then working backwards. For some that is carrying capacity, others range, speed, stability, etc.. It’s hard to strike a good balance if that is what you are after, not impossible, but definitely the most challenging. If you’re committed to using the PT hulls, you’ll definitely need to build around their attributes/limitations.
Thanks. Motors are 24v Caroute. They’re brushless, 120lb Thrust, and efficient -1500W in 1000W out @1500rpm. But cruising speeds is what I’ve built around. With the ESC still modulating, I get about 80% efficiency which allows me decent speed on Sun only from 600W of Solar.
