My first fast electric boat !

[DeltaAPmech]

Sorry it?s been a little while since I updated the build but life got in the way of goofing off. If you know what the pictures are of then you?ll understand the delay. My ?02 Jeep TJ had a badly leaking heater core. Well to fix it the engineers that designed the Jeep thought it would be great to make it so everything inside the Jeep forward of the seats has to come out all the way to the firewall just to swap out a 40$ part. Steering column and all. So I was busy. I got a little done on the boat after that so the next post will update ya.
Pete
It is nice to have a warm Jeep again !

[Xrayted]

Man that sucks Pete! Its like working on an old Jaguar. On some you need to remove the entire front clip, fenders and all just to get access the water pump bolts. Its as if there was no design consideration at all for any basic maintenance

[DeltaAPmech]

I used to like working on cars, but now it’s not as fun. I can’t believe the front clip has to be pulled for a silly water pump. It’s got to be in purpose to force you to the dealer !!

Time for the drive shaft install. I had to cut my build jig to allow the stuffing tube and strut to be mounted along with a hole for the lowered motor to allow the boat to sit flat. I made an alignment tool out of stainless to get the tube and the motor collet lined up to each other. Got it all squared up and secured the brass sleeve that holds the drive tube in place. I took a lot of time getting it as lined up as best as I could.
Pete

[DeltaAPmech]

I drilled and countersunk the mounting bolt holes for my modified motor mount and then got it in place. I?ll make a small cover for the motor. I built the supports for the two 4000mah batteries. I used a couple of small carbon rods to give a place for the battery straps to hang on to along with cutting slots in the beefy structure next to the battery. That should be strong enough to hold them in place. The batteries sit at a bit of an angle to clear the prop shaft.
Pete

[DeltaAPmech]

Not much progress to report. I had to go back to work, my shoulder is all healed up and now my wife and I managed to catch Covid for the first time so that?s kinda taking to zip out of me. Just before that happened I made the motor cover and got it secured and glassed over. Lots of cleanup work will need to be done. I?m also working on a cover to convert the air cooled speed control I have to water cooled. I?m going to see if 3D printing it will work. The jury is still out on that. If it doesn?t pan out I?ll carve one out of aluminum.
Pete

[DeltaAPmech]

I have been working on the water cooling jacket for awhile. My CAD skills leave a lot to be desired. After a lot of trial and errors I have one that fits pretty good. I got it to fit better when I started cutting up the test prints to see what was going on with the fit to the fins of the esc. I don?t want to cut any fins down at this point. I figured pushing the water back and forth thru the fins will give me a lot of surface area to work with. I am going to seal the cover to the esc with rtv and use zip ties or lacing cord to mechanically hold the cover down. I have seen water cooling conversions done like this to the castle truck esc?s before the hydra came out. I don?t see why it won?t work with this esc. The cooling fins are all one piece and my cover only involves that plate. The rest of the esc stays dry and it?s listed as waterproof anyway.
Pete

[Xrayted]

Looking good Pete! That's an interesting idea on the 3D printing, and water cooling the fins themselves vs using a cooling plate.

[DeltaAPmech]

Thanks ! This sure is fun building this boat. I sure hope it works! I got it RTV’d to the esc yesterday and leak checked it today. So far so good. It needs to hold up well, I’ll bet the boat would fill up quick if cooling water got loose inside the hull �� I printed it with PETG and at 100% infill so its pretty solid and should hold up to the temperatures the esc will create.
Pete

[DeltaAPmech]

Today?s project was to make a collar to keep the wire drive from leaving the boat if the wire breaks near the motor collet. It?s my understanding that when these fail it?s usually near the motor and when it breaks the shaft and prop will leave the boat and end up at the bottom of the pond. I?m sure I could have bought something to do the job but where?s the fun in that ? I made the collar the way I did to try to have it as balanced as I could. The 2-56 cap screws are stainless so they have some weight so I made everything symmetrical down to measuring the length of the screws to the thousandth. I didn?t want the screw?s themselves pinching the wire drive and possibly scoring it creating a stress riser so I made it so the aluminum collar does the pinching. The little hole is drilled to the same .098 diameter as the wire drive. I ordered my first prop from Dasbota ( an 1815-17 ) and it?s not the most inexpensive thing in the world so I?d rather be able to not loose it if the shaft breaks. 😁

[Gary]

Some strong advice my friend.....install some very good flotation.Most people will use some sort of foam but I ALWAYS have used spray foam only because I felt that every void in the sponsons needed to be filled to prevent any water getting in and it also offered much more structural strength. Your boat will be very heavy when batteries are installed and if it is fast 60 mph and up your chances are greater of a flip or blow over.
Your build looks fantastic and very well thought out....love it !!

[DeltaAPmech]

Gary I will do just that. Every spot I can get foam into I’ll do it. I wasn’t sure about expanding foams water absorption so I went with styrofoam. The sponsons are very full of it and the rest of the hull will get as much as will fit. Expanding foam making the hull stronger makes a lot of sense. It’s too late for this boat but I’ll keep it in mind for the future. Thanks for the sound advice !
Pete

[Gary]

Never too late LOL....you can shoot it right into any opening on the hull. It's the sponsons that really will hold a lot of water when an accident happens.
If you use the expanding foam be VERY VERY careful as to how much you use as it could possibly separate your joints and screw things up. Get the out door foam and do a little practice run in a can or something to see just how much it expands. I have been using it for years so I am used to it with no worries of hurting the hull.

[DeltaAPmech]

Earlier in the thread I had this shot showing the foam so far. I used the cutouts left behind in the laser cutting to pattern the styrofoam. It packed in there pretty tight. I?ll still add more when everything is finalized. Still got to run the waterlines.

[Gary]

Perfect !! Looks good. Like I said every place water can accumulate is weight on the hull to bring it down under.
Always expect the main entry to be the cowl and make sure it is VERY well secured to the hull.I only speak from the many times mine has cracked,broken off and what ever else but....I am also talking about a boat's that are going faster in the 60,70 and up mph range. My cowl on the PT-45 has 7 thumb screw downs and is well taped up before every run.

[DeltaAPmech]

Thumb screws is what it takes ? Guess that messes up my plan. I set up magnets to hold it in place and was counting on tape to do the heavy lifting of keeping the hatch in place when running. Watching M5 performance on YouTube he runs magnets on his hydros. I added a couple of formers to bend the cowl just a little so it flushes out better with the hull. I plan on filling the cowl with foam too.
Pete