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

[T.S.Davis]

I just don't think there's anything more satisfying than building a wood boat. Engineering, science, and art combines into a grown ups play thing.............and it comes in a box right to yer door. Perfection.

Try a wood build fellas.

[DeltaAPmech]

Time for the top fixed sheet to be bonded on. There?s not much to it, but apparently it really stiffens up the hull so the directions say to make sure the bottom is flat, so it?s screwed back down to the jig for this step. I also turned some little wood plugs for the carbon tubes. I?m thinking if water gets to where these tubes are then if left open it could flow to the whole boat. Probably never happen but it?s easy and light.
Pete

im not sure why the pictures flip upside down sometimes and I don’t see a way to fix it sorry for making you flip your computer upside down to look at them :-)

[DeltaAPmech]

I got the top skin cleaned up and prepared for bonding on the sponson assys. It feels like a big deal to do but it wasn?t too bad. The dowels line everything up nicely, it?s just a matter of getting the epoxy consistency right, spreading a good layer on both surfaces, clamping and cleaning up the squeeze out. The jig once again gives me confidence that everything is straight and true. Once the clamps come off it?s going to really look like a boat !!
pete

[DeltaAPmech]

One skin down one to go. I sure do like the shape of the sponson. The top skin really makes it look great.
Pete

[Xrayted]

It does look sweet! I have to admire you for taking on a wood kit as your very first boat build. I may get around to building a wood kit one of these days after I retire. I also want to do a big scale heli build at some point to add to my heli collection, but didn't have the man cave space to do so since I lived in the city in a high rise condo on top of a hotel. Now I have all the space in the world in my new house I bought in the 2019, but now its the time to do anything that's missing since I spend most of it on a Delta plane going somewhere else

I'll get there one day! Good luck and keep the build photos coming

[DeltaAPmech]

Thanks ! I'm having a lot of fun building it. I have to be honest though, it isn't my first wood boat that I have built. This is the first FAST boat, I have a few others but all of their speed combined wont come close to what this one is supposed to be able to do.

I scratch built the sternwheeler as my very first boat ( ten years of time ). Its so big that its tough to get in the water and complicated to run so I scratch built the little steam launch for quick trips out. Next up was ditching any mechanical propulsion so I bought plans and built the schooner. Last boat was a bit bigger so I bought a kit and built it so had one to ride in !!

A scale Heli sure would be neat, Are you talking a Hughes 500 or a Sea Stallion maybe even a Chinook

Congrats on getting space to play!
Pete

[Xrayted]

That's right, I forgot about the big steam boat you told me about when we were at the club together. The hydro should be a piece of cake then compared to the complexity of that giant steamer! I have only managed to get by the club lake for less than one hour since were were last together there several weeks ago, so hoping for some time at home with decent weather soon.

Yes, most likely a big 700 sized Hughes multibladed heli, or Eurocopter EC135 with a Fenestron tail. Ive already built a 500 sized hughes years ago, but it was only scale on the outside. Im looking at full lighted instruments, carpet, etc on a 700 if I ever get around to starting one. Ive also had a scale Eurocopter Dauphin years ago that was also 500 sized.

Hope to see the hydro at the pond soon!

[1coopgt]

Whoa Mad skills . Those are beautiful.

[DeltaAPmech]

That sounds like a pretty cool helicopter project. I’ve never seen one with a full interior, just semi scale on the outside.
1coopgt - Thanks! I don’t know about mad skills just lots of time and plenty of mistakes learning how to do it ��

[DeltaAPmech]

I sanded down the upper skins of the sponsons and got the cowl trimmed down to fit in place. Wow this boat design looks great to me ! It looks like its moving fast just sitting on the table.
Pete

[DeltaAPmech]

Well I?m never one to leave something alone. I like the looks of the full scale unlimited hydros, I know this isn?t one but what happens if I put fins and a wing on this hull? Does it completely mess up its performance? The little turbine exhaust won?t hurt anything I?m sure and this one is just a quick see what it looks like. I?m going to make something that fits well. I could make the wing assy removable and just run it when I?m just messing around. Anyone have any experiences with a wing on this size hydro ?
Pete

[DeltaAPmech]

I decided to just glass the whole belly in one shot rather than lots of little pieces inside. Besides being easier to lay, it will protect the bottom from hits from stuff in the water. Long ago the guy that runs the hobby shop near me said to glass the bottoms of boats. If it?s only paint water will get into the wood and suck it up like a sponge with every little ding and nick in the paint.
I just used 1 ounce cloth and just enough resin to get it all wet. When I built my wood canoe the directions explained that if any more resin is used on a wet layup than is needed to wet out the cloth the glass will float off the surface. The weave of the cloth should still be visible with the right angle of light and can be felt. Once it?s cured, the surface is skimmed with more resin to fill the weave. It makes for a nice strong well bonded surface.
pete

[DeltaAPmech]

I sealed up the area behind the sponsons and that pretty much seals up the bottom of the hull. With that done I threw in all the parts to make it run and see where the stuff fits and balances out the boat. It?s my understanding that it needs to balance on the center of the turn fin. In the build pictures ML Boatworks has on its site the batteries are up front and motor aft. If I lay mine out like that it?s not even close to balanced at the fin. It works out fine this way especially with the wire drive. The nice curve in the stuffing tube comes out just about perfectly for the motor being located in the front.

Anyone see any problem with this layout ?

Pete

[Gary]

Looks awesome !! What's great about building like you are is you can make whatever modifications you want as you go along.

[DeltaAPmech]

Thanks Gary you?re right and this post is an example of that. I hope it works like I want it too !

So it?s time to quit staring at this boat and start cutting all the pretty wood up. It?s intimidating to slice into the hull. I used the trick Scott has on his YouTube channel to get an idea where the stuffing tube will pass thru the belly. Clamped the strut to a scale, set the angle of the strut to 1 degree and measured where the tube met the scale. It worked out pretty good. I ended up lowering the motor a bit to allow the shaft to be as shallow of a curve as I could. I ended up with about 5.5 degrees of tilt on the motor and it lines up great with the wire drive system. I?ll have to build a little enclosure for the spot the motor sticks down but it won?t take much. The other thing I?m working out is the motor mount. I bought a nice setup but it looks like any time it?s disturbed I?ll have to go thru getting the perfect angle and that?s tedious. I?m going to make the whole assembly removable. The last shot shows what I?m gonna try first. Seems like it will work. I?ll secure 4 tabs to the sides of the mount assembly and then those will screw thru the reinforced belly. Those screws will be there to keep the motor in place but the loads from the motor pushing forward are going to be absorbed by the blocks in front of the mount that fit real tight against the carbon fiber plates on the mount system I bought. If it doesn?t work I have more wood and epoxy 🤪
Pete