My first fast electric boat !

[DeltaAPmech]

Hi guys, my name is Pete Stankovich,
I am jumping into the world of boat racing for the first time and I wanted to share my journey with this forum. I have been reading lots and lots of posts trying to learn how these boats are built, setup and run. You all have taught me a lot and I appreciate all the information everyone shares. I am sure I will have lots of questions. I have gotten a lot of advise from a couple of guys at the Atlanta Model Boaters club near me which has been great too. I have joined the IMPBA and plan on joining the AMB club when I get closer to done with this build. I have been advised to build for, and run in the P Sport Hydro class so that is what I will do.

So here I go. Just before Christmas I bought a ML Boatworks GSX 338v2 hull and began building. I started with a jig to keep everything straight. I used the information Scott Meyers gave on his YouTube channel here - https://youtu.be/V_LqtFjgHHw?si=Kbx98xlMin0zNakz I have watched most of the videos on his channel that relate to model hydroplanes. It has been a great resource!

First up was bonding all the frames and formers that are laminated together. I used wax paper and lots of clamps or weights to hold them till the epoxy cured. I am using MAS LV with the slow cure hardener for this build. I had it leftover from a 17ft sailboat I built from Chesapeake Light Craft. I really like this epoxy, it doesn't require sanding between coats if its done within a reasonable amount of days.

This is also the first laser cut kit I have ever messed with and I am amazed by the precision that the parts fit together, everything just lines up perfectly.

I have more progress but this forum only allows 5 pics per post so I'll break it up.

Pete

[DeltaAPmech]

Next I took all those frames and assembled them on the jig and glued them all to together and to the belly of the boat which was screwed down to the jig. I used a lot of scrap wood and deck screws to hold everything in place till it cured. I followed that with the sponsons. Here I used superglue to tack the parts together and then followed that up with thickened epoxy fillets at all the joints. I went with carbon fiber tubes instead of the wood dowels just to make it lighter and stronger. The forward dowel is a bit longer than stock and that allowed me to add another brace that picked up the outboard stringer on each sponson. It made the sponson a lot more rigid when i got that glued in place. I doubt it needs it but its fun to make little changes. The Jig makes it easy to keep everything nice and straight and flat.

Pete

[DeltaAPmech]

I like to try to make as much stuff as I can its just what I like to do. I have a small lathe and mill and lots of scrap aluminum from a big machine shop at work. I'm no machinist but I have watched and learned from youtube university and I have messed up a lot of metal and scrapped a lot of parts in my attempts to shape metal. So I made my own turn fin bracket from a chunk of 7075 and a fin out of a sheet of stainless. The fin is just eyeballed from images and dimensions on the internet. I really think I have too much curve in the fin. I'm thinking of undoing a bit of it. Seems like it should drop vertically down for a while before it hooks. Any thoughts ? Im willing to alter it, I want it to work well. I know I could just buy the correct fin but it saves me a couple of bucks and its fun to try. If it fails I can always order something.
Pete

[DeltaAPmech]

Next up for me was the outer skins of the sponsions. Those are curved a lot and needed a ton of clamps to get them flush to the structure. Seems like they came out good and I added a few fillets of epoxy on the inside to beef up the bond after the first cure. I kept it all on the jig and secured to it to keep the boat straight. I am really glad I took the time to build that jig! I followed the outer skins up with putting the inner riding surfaces in place.

Pete

[DeltaAPmech]

I got a small sheet of carbon fiber to use for the two aft ride surfaces on the sponsions. Again, I'm sure its not necessary but it seems stronger and looks good.
The shots of the boat on the table are for show, the sponsion assemblies are just slid on the dowels. Long way to go before I glue them on.
Pete

[DeltaAPmech]

This slowed me way down. I have a lot of time in this silly rudder bracket. I bought the rudder blade from speed master. I haven't got the skill or tools to pull off the cooling water holes in that rudder. Also I don't have any idea of the dimensions of a proper rudder for this boat are. I'm glad I bought it, its a beautiful example of machining. I actually bought two of them in case I destroy this one or cut it too short when I get around to tuning the boat on the water.

So this was from a hunk of 7075 T6 aluminum and I just wanted it to look like it looks and positioned it on the boat where it looked abought right. Since I am brand new to this its all just guess work from what I have seem in pictures out there. It sits to the left of the prop, about the same distance from the transom as the prop will be. I didn't take a ton of pictures of all the stages of cutting it but you should get the idea. It has Two Delrin bushings on the bracket and a stainless pivot pin that is secured with a 4-40 set screw that is positioned in the slot that holds the rudder blade.

Pete

[Xrayted]

Looking great Pete! Hope to see it running at the club soon!

[1coopgt]

Looking great.

[DeltaAPmech]

Thanks guys ! I am looking forward to running this boat but nervous at the same time. The slow boats I have really have no chance of destroying themselves, but is feels like this one has that potential ��

The updates will come slower now. I have caught up to where it is now. As I build I’ll share the progress.

Pete

[DeltaAPmech]

Here is some more progress. I have the servo mounted, I put it forward on the left side partially in the sponsion. The thought is trying to keep weight out of the back of the boat for balance. I used a carbon fiber arrow shaft for for the majority of the pushrod and the ends have delrin blocks turned down to the inner diameter of the shaft and threaded for stainless rod cut down for 4-40 threads with ball ends. The delrin was epoxied in place and then drilled and pinned with a .128 dia carbon dowel thru everything to keep it all in place.

I also got the nose of the center section in place and pretty close to final shape. Just to make it take longer and be more work I removed a good bit of wood from the nose block . Its still plenty strong but lighter.

Pete

[DeltaAPmech]

Floatation foam was this evenings project. I used a homemade hotwire cutter. Its a piece of .020 stainless safety wire under tension and a model train transformer. The cutouts left behind on the laser cut sheets gave me great patterns for shaping the blocks of foam. I packed the sponsions full and also added foam to the aft part of the fuselage.

As far as I can tell the two blocks in the back can support around 3lbs and the two sponsions look like they have about the same amount of foam, maybe a bit less. That gives me 5-6lbs of displacement. Not sure what the boat will weigh when ready to run. I don't want it to be able to sink even if it completely fills up with water. I want it to be overkill because I know the boat can be damaged and missing something like a sponsion
When I know the all up weight I'll do the math to see if I have enough foam.

Anyone have any advise with floatation foam, or anything else I'm doing? Like I said this is all new.

Pete

[DeltaAPmech]

It looks like fiberglassing the belly of the boat is needed but what I am wondering is it ok to just glass the outside surface of the bottom in one big sheet? The pictures of the boat being built show lots of small cloth pieces being put on the inside of the bottom. It would be easier for me to do the outside and it seems like that would help protect the wood on the bottom in case of a hit from something in the water.
thanks for any advice
Pete

[1coopgt]

If you haven't watched or sub'ed to M5's channel you should . I haven't built a wood boat since I was a teen. Keep up the good work .

[DeltaAPmech]

Thanks, your right the M5 channel is a gold mine of information. I have watched lots of what he posted and I’m rewatching as I do specific tasks.

[DeltaAPmech]

Not much building progress to report except one coat of epoxy to the inside of the hull and I got something really cool in the mail !!
Pete