ryan_t888

I built this boat completely out of 1" and 1/2" pink insulation foam. It is CURRENTLY powered by a 700 size drill motor using a plane ESC. C-55 from Electrifly

I am using a standard Futaba servo with a Futaba 3PM 3channel/FM radio. The rudder is from the nitro hammer and the strut is from Octura. The prop is a Prather B-215 that I have cut down(1mm) to 40mm and removed the tongues. I am using a .150 to 3/16 flex to prop shaft.

I am using 2 6-cell Nimh 3000mah from Team Orion.

The hull was designed on Cad first then SolidWorks. A member on this electric forum has seen one of the first drawings on SolidWorks that I had posted a few months ago. I can't remember who I was speaking to but it has been changed slightly in size and design since then.

Length: 26inches
Width: 10-1/4inches

I have decided to call it a TunnelCat since it has mixed characteristics from each hull type.

With that setup I have GPS'd it at 24.9Km/h (15.6mph) before the ESC held too much condensation and fried.

Future plans is to drop the ESC and motor from the SV27 BL RTR. It should get me over 25mph easily. Then harden the foam and apply some paint!

Ryan

jdoug

I built this boat out of balsa and blue insulating foam. I covered the sponsons with econocote and an iron. The ride pads are made from lexan and epoxied on. The boat is from modified plans. With a 17T double motor and 7 cells through a duratrax streak car ESC, I'm seeing 20MPH+ Decent speeds for a 19 in. cat. turning an x435 through Octura hardware. This thing really handles the rough water too! If you haven't already, you might want to glue some lexan or polycarbonate to the sponson bottoms as a ride pad. I'm sure you'll see a little better speeds.

Wheelnut

My Feedback: (81)

Very cool ryan, How does it run? Some vid would be real nice

ryan_t888

I'm hoping to harden and paint the foam in the near future. I have used several methods in the past. I may go with lexan strips on the bottom, I'm not sure yet.
I have used monokote to cover balsa on a plane. How well does the econokote work for covering foam. Will it be dent resistant?
Thanks for the comment

I was going to get some vids but my ESC fried before I could break the cam out, sorry. I have a vid of my nitro tunnel as a much, much better substitute!

It runs maybe as fast or a bit faster than a stock electric hammer. Remember this is a 700 size DRILL motor. High torque, low RPM's. It doesn't handle all that well because I ran it on bare foam.
What do you think about dropping a SV27 BL motor/esc? I'm waiting for the boat to come out along with any problems with the boat after a few months. So maybe I'll pick a BL motor up around Christmas.

Ryan

jdoug

Econocote works really well for covering foam as the temperature needed isn't quite as high as the monocote. Unfortunatley, it does nothing to add strength to the foam. It will dent very easily but, if you're careful with it, it will hold up and is extremely light weight which is what I was going for.

ryan_t888

A site that I found a while ago for scratch built foam planes mentioned using one coat of white glue over the foam. Then sand it smooth and use another coat. This is suppose to harden the surface of the hull and then you may apply Ekonokote. This is what I want to do, would it work well with the foam?

Ryan

Rampede

thats awesome, where can i get some insulation foam? and how much is it..how do you cus it, etc etc.....

ryan_t888

Thank you,

The hull cost me less than 20 Canadian dollars. (This does not include the wood I used for the transom and motor mount) This is for one 8X4 sheet of 1 inch insulation and an 8X4 sheet if 1/2 inch insulation foam.
Try Home Depot or maybe Lowe's. Not sure if they have it at Lowe's as there are no stores in Canada yet.
I cut all the material using a scroll saw.

Here is a picture of a Hydro I will be making in the future. I'm not happy with the way this turned out so far but as with all designs including my TunnelCat it takes a few tries.
Program I used is SolidWorks.

Ryan

CadillacDTS2001

cool could you make me one of thoes ?
no no im just kidding
so do you realy want to spend all the money on the BL stuff , why no hop up your nitro >
any way good job
your next one id like to see some smother lines

ryan_t888

I like sharp edges, the more the better. When I designed a model with a more of a rounded out hatch, it looked fake and odd.

I think this boat would benefit from a BL system. I need more speed to reduce the wetted surface. In the next couple days I plan to sand it down to a nice smooth finish and then start thinking about what steps to take after that. I'm still open for any ideas on the SV27 BL motor/ESC and covering the foam.

BTW, I will hop up the nitro and this. It is always nice to test the limits of something you designed and built. I may be able to keep up with those Back Ordered SV's using the same motor/esc.

Ryan

Stokes

way to go Ryan!!!! i think it was me who first saw your plans - i must say that you managed the build very well...am dying to see the vid!

Andrew

ryan_t888

Thanks and yes it was you.

The next time it hits water will be with a BL system. It may be a while as I am waiting for comments on the SV27 boat. The only vid I have is the one posted in the nitro forum of my tunnel.

Ryan

TCEAGLE1

Hey guys, great job on the scratch builts. Here is a small rigger that I have been working on. It's based on the Blizzard plans, and is my first attempt at boat building. I say based, because I did the best I could with printing the plans and piecing them together off of the home computer. It is made of lite ply and balsa with carbon fiber booms. It is powered by a 4200 kv brushless outrunner and a 40amp controller with a 3s 2100mah li-po. The boat runs fairly quick, but the motor gets hot real fast. I can't complain too much cus' I got the esc and motor combo off ebay for like $50. I hope the pics show up with this post I'm a newbee at this too. I've also got a blurry movie that I'll try to post later.

CadillacDTS2001

i think that the sv27 BL stuff would work good !
but do you have a video of the boat running ?
also you should look in to fiberglassing the hull , and drop some mereatic acid in i and the foam will be all gone !

TCEAGLE1

Ryan,

Here is the video of my rigger. ( I hope this works) Its blurry, but you can make out whats going on. The sv27 stuff should work great, but when will it be available? Thats what I wanted to put in this boat, but I was too impatient to wait for it to hit the market. I am experimenting with this set up for now, 4200 kv outrunner , 40amp esc, 11.1 li-po. Motor and esc are made for electric helis and was about 50 - $60 for the combo on ebay. Its just an idea of some other ways to experiment!!!!!!!

[link]http://www.youtube.com/watch?v=1ZOU6CLk9ro[/link]

ryan_t888

It looks like it's moving pretty quick but it doesn't seem to be winding out. I could be wrong? You should be getting a unloaded 40 000RPM with your setup. Maybe a loaded 25-30 000RPM?

What prop are you using? Does the motor/esc/bat get hot after a runtime of...? Does the motor actually say 4400KV on it? Got any pics of your setup inside?

The SV27 should be in around mid September. I'll wait and see how all the people with Back Orders like the boat and if they have any problems with the motor/esc combo.


Ryan

Villain4|IVstar

To strengthin the hull you could try some fiber glass resin and coat the whole thing. I have also heard of carbon fiber but that may be a little overkill.

CadillacDTS2001

hey , with the SV27 motor , what is the KV of it ?
becuse i think it might tear apart the boat
also you might want to watch out with heat and it might mealt the foam

and as for fiber glass , i would do it ,
see ryan there is 2 prople who say yes !

TCEAGLE1

I think you are right about it not winding out. The esc gets pretty warm and the motor gets hot. The battery just gets warm. I am using a octura x430, waiting on a x427 , with the strut raised as high as it will go. I was thinking of trying a lower kv motor. Here are some pics of the inside.



pics not working.........I'll try agian later.

ryan_t888

I would even cut down that X427. I'll post a pic of the prop that I have cut down for my boat in the next few days.

If you do decide to get a new motor, I would go with one around 2000KV or even less. Then you could prop it more effectively.

Pics look good, Get some video of it with the X427.

Ryan

ryan_t888

Here is the cut down Prather B-215 in comparison with a new one. Also size comparison with my tunnel vs TunnelCat.

Ryan

CadillacDTS2001

wow there is a big diffrence !
ever think of putting a electric OB of the stern of that tunnel ? like a lmt BL or somthing ?
also how much have you done on the boat yet ?

TCEAGLE1

Ryan,

Thanks for the pics of the prop and the info. I cut down the 430 and the 427, but the boat "hopped" real bad. It still hops a little with the stock 427, but the heat is way down and I can actually run it for a couple minutes at a time.

I'm running a 40a esc. Do you have any motor suggestions that might work with this controller?

Here is some video of it with the 427, (sorry it took so long) and the link below it is with a x632. (I had the prop so I had to try it) It ran good for about 30 seconds and the heat started slowing it down.

How is the tunnelcat going? Are you even able to still run your boats beacuse of the cold? We're still in shorts and flip flops on the Texas coast.

Tim

[link]http://www.youtube.com/watch?v=nIUeihI49fQ[/link]

[link]http://www.youtube.com/watch?v=NqGxqM8miPg[/link]

ryan_t888

I'm not sure on the motor. I like the first vid the best. Have you gps'd it yet?

I've only done some heavy sanding to the hull in order to prep it for sealing/paint. My plan is still to use the SuperVee motor and esc.

Ryan

ryan_t888

If anyone is interested in seeing what ended up happening with this thing, I'll start a new thread after the weekend. For any subscribers of this thread I'll leave a link in here to the new thread.

Ryan