2015 Outrigger Hydroplane: a Foam-core & Balsa Prototype Build

[ShaneHopkins]

Hello, I am new here, new to outriggers, new to scratch-building boats.

That said, I bring diverse experience from other types of RC, Racing, Scratch Building, etc. I am building an outrigger hydroplane prototype from foam core board and balsa because I have experienced such incredible progress with this material in several other hobbies, scratch built fast-electric aircraft for example.

So, after much frustration in reading forum posts from 2008 and no clubs or organized events anywhere near me, (seems participation this sport on a competitive level dropped off the planet around 2009 - whats the deal with that?) I decided to just get started in building.

This is something I have wanted to try for a while and watching my friend crash his 100+ mph ducted fan electric foam-core jet plane over and over (and always repairable at the field in less than 60 minutes) has motivated me to bring this durability and economy to a fast moving water vessel.

I considered a mono-hull and a cat hull, but nothing appeals to me more than the outrigger hydro - so it be. I would like input from those of you who have knowledge, experience, and good intuition when it comes to prototyping things without a benchmark data-set - and just building things from your gut (some of you have done this when you just need to start somewhere and your exploring uncharted territory) some might call this "eyeballing it".

I would really like some good feedback here so if you uncomfortable operating outside of your clubs rules and regs, this is probably not a good thread for you to follow as it will probably make your skin crawl. I want to show some of my "flying" friends that I can also build a fast BOAT out of foam core board and that this economical and almost indestructible material is not just for planes & jets. Another motivation for me is that I live in Fletcher NC (near Asheville) and there is no where to run boats except for private lakes and ponds. So, it is much easier to get permission to run your boat when it is made from foam, I actually have permission to test on a nearby pond as long as the boat is made from foam and I don't run anything loud on Sundays.

On to the design

Materials used:

Hull - Dollar Tree Foam Core Board ($1 per sheet) 2 sheets for this application (Total = 2$)

Hull Covering, decking, supports - Balsa Wood and other Modeling-grade plywood

Hull Strengthening - Balsa, Aluminum, Carbon Fiber for struts, strakes, skis, skids, mounts etc
Adhesives - CA glue, elmers white glue, Gorilla Glue, Epoxy

Hardware - ?

Power Train - ?

Finish - ?

Here are the pics of the initial hull and sponson build (Design is based off of dozens of traditional competition outrigger designs)





Still learning the forum processes for images and such so here is a link to the album (not sure which is better for post attaching image vs link to entire album?)



Please feel free to speak up and say what it is you see or don't see.

I would love some suggestions on design, size, weight, hardware, power, finishing/covering, and remember this is not a competition boat, it is an experiment to see if we can make a strong and fast boat from foam-core board as the primary material. I am all for using other materials to enhance the design, strength, and performance. Carbon fiber, Aluminum, Wood, is all good as long as it is easily obtained at a reasonable price. Thank you to the many good people who share their knowledge here... Shane

PS - more pics and updates in a few days

 

[larcor69]

Welcome to Intl., waters, I am sure some one with much more experience with rigger's than I will chime in, what are you planning to power your rigger with?, electric, nitro? and what size?

 

[Andy Brown]

Welcome to the world of r/c boats!

Electric would be the best choice. No need for fuel proof finish. How long is the boat? Maybe 2S for a boat up to 28"....4S for a boat up to 36".

P.S. Please post your real name. It's a rule here.

 

[ShaneHopkins]

2015 Foam-core Board & Balsa Outrigger Hydroplane Prototype Build Update

Hey guys, my name is Shane Hopkins (my OP did not include my real name - sorry) and I wrote the admin about trouble when registering - The system would not accept any variation of my first and last name - in fact anything with a space generated an error, underscores too, even tried my first and last name together with no spaces or underscores = Error!.

So, I looked and saw many others with "Forum Nicknames" so I tried mine and it worked. Anyway I got a PM saying I was in violation... glad they did not delete my post and they have all my info if they need to change anything.

Now, Back to business, here are some answers to some questions you posted, some new questions I need to ask, and some new photos of the build.

Larry Brown - Thank you for your reply, the hull is 26" and weighs about 4.5 ounces thus far but still needs covering/finish/mounts/frames/braces/deck. I was hoping to do an electric power train but have the least experience in this aspect of RC Boats.

IC engines make sense to me when it come to my mechanical ability but electric seems so clean and efficient with less tuning. I do have a home-built flow bench that is great for making 2 and 4 strokes scream BUT... I am totally up for learning all about fast electric vehicles/vessels!

Is it easy to upgrade electric components once comfortable in operating the boat at speed?

What can be engineered in to my design to ensure ease in upgrades of electric components?

Is there a difference in costs gas vs electric (regarding non-competition or recreational speed and performance)? That brings me to budget, I was hoping to power the boat with everything including running hardware for around $500 (not including Tx & Rx) is this realistic to power something fast enough to be exciting/challenging?

Larcor69 - Thank you for your reply and as stated above, I am undecided regarding power and size (see my length and weight specs thus far above.

Update on the build:

I came across some sponson designs from some RC fanatics in sweden and decide to modify my conventional sponson shape to something more modern and hydro-dynamic. So, I incorporated a stepped design and used a sequential tapering of alternating laminates (Foam-board/Balsa) to create a better shape using less mass/same footprint. Here are some pics of where I am going with the sponsons:

First design was more conventional or traditional outrigger shape (these have not been shaped but are close the the original ideas final shape and size:









The new sponsons are solid, not layed-up per say, but stacked (?) or sandwiched I guess.





















Any thoughts, ideas, or feedback is appreciated.

Bonus Pics of Hull Progress:











PS - No one going to take a stab at me regarding this Foam boat being a complete dog and waste of time? Not sure if I'm impressed or disappointed! Really would like something innovative to come out of all this though. Please speak up if you have an idea that you have not been able to try but would love to see implemented in a build - I do have some surprises regarding propulsion design regardless if gas/nitro or electric...stay tuned!

 

[gooycheese]

Good Luck,

Honestly I dont see what your building, but that dont mean it wont work. I would guess that you should be able to make this move for well under $500. A .12 hydro is under $500 for sure and plenty exciting/challenging. FE would be under $500.... go with something like whats used in the UL1 by aquacraft.....i would think if ya went to like hobbyking you could go FE fairly cheap....

good luck

p.s. I added shane hopkins to your signature line =)

 

[Jerry Betke]

Areas that you will need to give some thought to are the transom, engine / motor mounting and boom tube support. Boom tubes are a high stress area and need support in the hull and sponsons as well. The transom is also a real high stress area, especially if you hit something in the water. I have seen transoms torn off the back of the hull from the impact of hitting something. These are just some basic information points for you to consider in your design.