My first RC boat build, modern day 1/8 scale brushless Hydro! WOO HOO!

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nicholashansen

Well-Known Member
Joined
Mar 1, 2015
Messages
126
[SIZE=14.6666666666667px]heh, excuse my excessive enthusiasm (if there is such a thing
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) as I have already completed most of the work in this project, much to my delight.... I want to thank anyone in advance that actually takes the time to read through this entirely, as I regret not posting this earlier in time. [/SIZE]

[SIZE=14.6666666666667px]As the title says, this is my first RC boat build of any kind, and I have practically zero experience driving anything whatsoever, sans 2 occassions of driving a traxxas blast more than a decade ago at least. When I first started this project, it didn't take long after recieving my hull to realize how far in over my head I had got. Mind you, im still in school trying to get a degree and currently working part time with my familys business, so time and energy are the most valuable of resources! [/SIZE]

[SIZE=14.6666666666667px]But its been over 4 months and with some patience and a little luck, I have thankfully reached the point I am now. When I say luck, I am referring to some of the amazingly generous individuals (one in particular whom I really cant thank enough) for lending me their extremely helpful guidance, insight, and constructive criticism. To really think how much help I have recieved, the money and time expended, and to still be over 4 months from when ive started without the boat even touching water yet, really is a testament to the difficulty and attention to detail that is required to build a 1/8 scale hydroplane (and in my opinion, brushless/lipo power constituting a massive change to the entire schematic of the build, which brings me to my next point). [/SIZE]

[SIZE=14.6666666666667px]I am still anxious and a little worried as to how the boat will run, especially considering my lack of experience in such. Ive lived in Seattle all my life and my father along with the rest of the family have always been avid boaters and fisherman, so I have a pretty good understanding of the overall performance/perspective of boat dynamics. That said, its obvious that hydroplanes, are far different from "normal" boats in relation to their center of gravity, ride surface, adjustments and tuning, etc. Knowing this and researching as much as possible before making any purchases, I knew I wanted to go brushless, period. That was a priority, along with a fiberglass hull. The latter priority I figured would save me a ton of work, as I am not exactly the best craftsman and I ignorantly assumed that fiberglass is always "better" than wood (boy was I wrong!). Although it took me a while after having my hull laid up and recieving it, and consequently building into it for some time before I realized why with an FE setup, a wood hull is most likely the best option, but Im going to sum up my outlook on how I drew this conclusion with 2 simple things: Roger/Newton Marine and ML Boatworks. Being that ive lived in Seattle and I also frequent Offshoreelectrics and most other boating forums, I felt pretty darn silly every time I went to work on my nitro intended hull.....[/SIZE]

[SIZE=14.6666666666667px]I really put myself through alot of trouble through trail and error, tedious work and redoing things numerous times in order to simply emphasis a few key features that I believed were essential to making the boat run well as a nitro converted to brushless. Now to generalize, I did my best to achieve this by simply emulating the ML boatworks scale builds I have seen. There hasn't been a single time that ive seen ANY sort of ML boat that didn't run splendidly, and of course the growing pains previously mentioned are justified and in fact much preferred to the growing pains associated with a "bad day at the lake" so to speak. Ive seen alot of builds like mine that are fiberglass hulls meant for nitro, that attempted to run FE and one common trend ive seen is people placing their lipos where fuel tanks would go and putting ESCs in the/a radio box. So basically, they are trying to run the boat as if its nitro, with electric components, just because there is little molded lip in the hull somewhere and suddenly the entire layout has been dictated! no consideration to COG, balance, etc.[/SIZE]

[SIZE=14.6666666666667px]The first thing I emphasised was placing my lipos in the correct spot, as I knew they would be heavy. I quickly learned from viewing alot of the ML boatworks builds that they all would place lipos more forward in the boat than anything else, and always in the tub, not spaced apart under the decks. When I first noticed this, I thought "oh got it, good to know." Little did I know what a huge commitment this would require!! I made a mistake by purchasing my lipos very very late, after I bought the vast majority of other components and installing them too. Once I finally got my packs, I realized that I didnt even leave remotely enough room for them, not in width, length, or height. and not just in the space designated for them, there was now no room whatsoever! so I had to basically gut the entire boat. And at first that meant removing all the gear and tearing out the motor mount and the wood bulkhead and lip i made, but even after that I still felt like the batteries were just too honkin big for the front of the engine tub! So I started referencing some of the build logs i like to look at, and after a while I realized the key difference in how the wood kits are able to fit such large battery setups so far forward in their hulls. the floor and belly pan from the cockpit nose and back, runs much deeper than my hull! that simple! and considering the fact that a hydroplanes design with sponsons and the inside tunnel having plenty of space above the water, I figured, why not give my hull a deeper floor for that area?? so thats what I did. I proceeded to tear out a huge section of the floor with the dremel, going through 2 floors and a foam core to do it. I built a nice plywood belly pan and sanded the edges smooth, added some fairing filler, fiberglassed it, and faired over it all with some glazing putty and more fairing filler. This was the best thing I did for this build. Not only did I enable myself to use practically any set of batteries I want, I also was able to install my motor in a much better position as well, and now the COG can be lower and in much better position.[/SIZE]

[SIZE=14.6666666666667px]the 2nd emphasis was protecting my components. One observation that resonated with me at the beginning of all this was brushless boats having tape along the cowls/hatches to ensure a seal of ALL the of the excessive "inside" components (keyword inside). I never noticed this with nitro guys because obviously they only seal their radio box and usually they dont have to take the tape off for quite a while. Then, after looking at the ML scale builds, I really liked the idea of a "sub hatch cover" especially since I didnt like seeing tape or the idea of taping an oddly shaped surface. I personally feel like I dont see sub hatches nearly as often on boats that I personally think need them. Most sport hydros are already designed with flat edged cowls that can be taped easily. On top of that, having a "radio box" made no sense to me in an electric build, as if your sealing off the motor and ESC and batteries, why not just have the 1 single servo you need and reciever in there too? It would only make sense if you were simply skipping this step, or just are tempted to use the radio box molded into your nitro hull. Well I ended up building, tearing down and building a new lip and sub hatch cover 3 times, and made 4 different covers. The first setup I just didnt like as I did a bad job and used almost zero plywood, the 2nd I had to tear out as it sat too low as I realized when my lipos finally were bought and shipped to my house. My current setup, I really nailed and im very happy with. Now I have a nice flat edged, rectangle hatch that is under the cowling and is extremely easy to tape seal, and also, I dont need to permanently seal off my strut right away either as the water wont go anywhere but the small area of the back end of the boat tub. Every ML scale kit is designed this way and all the other kits at the least have square outlined cowls and step down lips along the tubs so the covers/cowls sit flush for tape.[/SIZE]

[SIZE=14.6666666666667px]Lastly, I have and still am concerned about weight management. I feel as though the boat is pretty heavy to begin with, and on top of my modifications and a tad bit of over-engineering on my part, im not going to be suprised if the boat is over 20lbs RTR. I used too much wood on the boat and thus used FAR too much epoxy sealing it all, as I had trouble getting into certain areas inside the boat and I could only have peace of mind that i sealed 100% of the wood was if I really gobbed epoxy into those hard to reach areas..... [/SIZE]

[SIZE=14.6666666666667px]However, all that difficult stuff aside, I am pretty happy now as to where I stand with the boat now, as I had temptations to just give up and perhaps restart with a different hull, or maybe just go and pickup a .67 engine from Stu Barr or even OPS (local), or go and get a UL-1 first and go from there (seriously lol). Thankfully, I didn't do any of those things! The learning experience and gratification of seeing the boat come to fruition have been great enough in itself that its been worth it to stick through. Not to mention, since posting pictures of my most recent progress socially, its been amazing how many people, especially local guys, who have reached out with a friendly hand. This really does seem like an awesome hobby!![/SIZE]

[SIZE=14.6666666666667px]I could go on and on about what ive done so far on this project and what ive got planned for my next project (i have a rather large package arriving tomorrow and ive been waiting a long time for it
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), but for now Ill just post some pictures of the builds major points along with the link to the original thread I made on offshoreelectrics. Ill make another post here soon with more pictures and document the progress in a more timeline oriented progression. I really encourage anyone that has any questions, comments, or constructive criticism to please post, as I enjoy any sort of discussion, especially if it involves science and engineering haha. Also, I have boatloads (yes a whole LOT of pun intended baby!) of pictures too![/SIZE]

*These pictures consist of the most recent state of the boat, I just put on the first coat of primer, Ill be filling a few more minor pinholes/imperfections then shooting another coat or 2. The first coat was brushed on
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heres some specifications:

-hull is a epoxy fiberglass and carbon fiber 1/8 scale T5 from Phil Thomas, with alot of modifications. To make the boat more scale accurate to a T6, I rounded off the tips of each sponson, narrowed the ram wing and reshaped it, and I shortened the picklefork depth and offset each side of the cockpit.

-Setup is:

Hyperion 4035 800kv Outrunner

Swordfish 240amp HV controller

Revolectrix 8s2p 5500mah

Octura x450 2 blade

-For Radio gear, I have a Futaba 3PL, but for some reason, I have really been feeling like getting a stick radio, particularly a Futaba 4GRS. I know this may sound weird, but it just seems like it would be more comfortable to me when I imagine it. Also, I have a Hitec servo, i forget exactly the model. It was 49.99 and came with a nice blue aluminum servo arm.

I also have a NEU 1527 1.5Y, with a very nice motor mount from Peter Zicha, but ill be using that in my next build, and I also have 2 packs for a 10s setup, and I have an MGM 25063 X2 series ESC on its way, its coming overseas so may be a little bit. Ill run an Octura x450 3 blade for that setup.

[SIZE=14.6666666666667px]Thank you![/SIZE]

[SIZE=14.6666666666667px]-Nicholas[/SIZE]

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nicholashansen

Well-Known Member
Joined
Mar 1, 2015
Messages
126
If your making it the T6 hull you will need to add the rear swim deck.
Well I wasnt necessarily trying to convert or register the boat as a T6 hull, I just didn't really realize until I got the hull and had observed numerous pictures that my hull was lacking a few key features that I felt were small changes overall but made a big difference in the overall aesthetic of the boat. From what ive seen, most T6 hulls from ML and Steve Gualtieris T6 hull have a picklefork depth of about 12", whereas mine was almost 16", a very big difference.

Which is the swim step again? is that the extension on the left side of the real boats? I wanted to do this to the back of the boat but it would have been too much work
 

nicholashansen

Well-Known Member
Joined
Mar 1, 2015
Messages
126
Here is some pictures of the hull when i first got it and some earlier in the project. Compared to the pictures posted in my OP, you can clearly see the difference in the front of the sponsons, along with the relatively flat surface under the hull by the cockpit. Also just a few pictures of how I did the extensions on each side of the cockpit. Only the picture that has the lipos in it are after the ram wing was shortened.

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nicholashansen

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Joined
Mar 1, 2015
Messages
126
Forgot I havnt posted anything here in a while, but nonetheless there hasnt been a big amount of progression for me to display, aside from just more bodywork and prep. My most recent coat of primer was my first time spraying and it went pretty well overall, but I ran out far quicker than I thought I would, so im waiting for more from Klass Kote. Obviously I dont have any experience to really make an educated statement, but I really like that stuff, has made it easy for a noob like me lol.

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nicholashansen

Well-Known Member
Joined
Mar 1, 2015
Messages
126
Looks good but keep it off the couch. You'll have the whole family itching from the fiberglass particles.
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ya, just did that for the pics. Me ma is in the hospital for hip surgery and im throwing out the old couch and moving her bed downstairs
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thanks for the tip
 

nicholashansen

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Joined
Mar 1, 2015
Messages
126
Thanks
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i finally got my package my package of more KK primer so im going to hopefully finish up the last few coats today. That and Ill seal the sub hatch cover with epoxy.

Im going to sell my Swordfish 240hv ESC, as I was able to get my hands on a Castle hydra ice 2 HV200, ive been wanting one of these for a while and im going to wait until I recieve it before I take the boat out for the first time. Its already got some 6.5mm bullet connectors soldered on, does this sound sufficient for the 4035 and 8s lipo?
 

big al

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Joined
Aug 14, 2005
Messages
269
I am keeping my eye on this build...........Going to be doing the same soon!
 

nicholashansen

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Joined
Mar 1, 2015
Messages
126
ah I forgot how long its been since I posted in this particular thread, ive had one on OSE for some time and ive mainly had my attention on that one.

So based off the last pictures I posted, I have literally spent any time working on the boat since then, 100% dedicated toward surface and bodywork prep for the rest of the primer job... I just finished laying the last bit of primer yesterday, at least as far as whats done before the maiden voyage. I anticipate that ill still spray a little bit more to just polish the last few subpar spots, but overall, im very happy with how its turned out and feel confident taking her out for a few spins
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Im still a little concerned about the weight, I need to go a get a proper scale still and I keep forgetting. I imagine an ideal weight at least for me would be anything under 20lbs just before hitting the water, im sure that sounds very heavy in general, but considering my experience and the way the hull has been engineered, and the brushless setup, id be happy with achieving that goal. A recent builder on OSE who is also in his first 1/8 scale, built his 2006 Elam from an ML kit, setup for 10s with the standard 1527, and his came out to 19lbs RTR, which suprised me. I figure with my epoxy glass hull and high amount of bodywork, anything near that should be sufficient, for me at least.

ive also got another concern as of recent, mainly due to my lack of understanding completely the dynamics of brushless setups and the relation between lipos, power draw and such. I have juggled the setup ill be using for this project quite a bit, as I am worried about my lack of driving experience vs having a race ready, competitive boat... As of now, I have both 10s and 8s lipo setups, and I have both the NEU 1527 1.5Y and a HS 4035-800kv. Now the tricky thing is the ESC for these configurations, as I now have a Castle Hydra Ice 200HV (version 2?), and I had a swordfish 240hv but foolishly sold it.... I didnt realize that apparently the Castle is rated at 200 amps MAX, whereas I always figured ESCs had a surge rating. Ive been led to believe from a very trustworthy source that on 8s, the outrunner will need more power than the Castle can provide. Now I would prefer not to run the NEU right away, and Ive also heard that the 4035 isnt particularly suited for 10s and is much better off with 8s, not to mention I feel more comfortable with my first time driving with 8s until I get more comfortable. Should I bite the bullet and get another Swordfish? or just run the 4035 on 8s? BTW, I have two props ready for the water, Octura x450, both 2 and 3 bladed versions.

thanks for any input guys!

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