First foray into Twins

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RaceMechaniX

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Apr 27, 2007
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Nope it is not a Nitro or Gas twin, but an FE twin with enough juice to run against any power plant......hopefully.

This project has taken a couple years to get off the computer screen and onto the build bench and it's finally to the point where I can share some pics.

The tub measures 45" by 7" and is built from laser cut birch ply, reinforced with G10 and then carbon to wrap around all the walls.

Power will come from two Lehner 2260 size motors spinning 1/4" cables in the same direction. ESC's are a matched pair of the newer Schulze 40.161's.

The controllers have two pairs of battery leads for each ESC, one pair will go directly to a battery and the other pair connects to the other controller for IMPBA legality. Joining the controllers has the benefit that power will be drawn evenly from the batteries. It also allows me to run 3 or 4 packs in parallel for added capacity or just available batteries.

I intend to run this as a Q-hydro for IMPBA or T-Hydro for NAMBA both on 6 cells with at least 2 parallel packs. The RPM range should be similar to a big block nitro motor on 6 cells. I can always increase to 8 to 10 cells with higher RPM's if needed. A small electric water pump driven off the third channel will provide post run cooling.

Hardware on the back is from Mark Grim.

Next steps are to paint and then build front and rear sponsons.

-Tyler

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Looks great. Wish we could meet up someday to race our Riggers. I have two "T" or Open riggers that scream. I have never lost to a fuel boat.
 
Very nice Tyler..I'm pretty sure it will be a blast....I built a twin with less sophisticated electronics and she

s a real screamer too ! Congrats Gill
 
Thanks Guys,

@Gilbert, the pump is from TCS Micro Pumps out of the UK. Be prepared for sticker shock, but these are fantastic little pumps.

@David, I have burned my fair share of lipos and boats up pushing the limits, the plan with this one is to be reliable and consistent. I won't be pushing more than 180A so the power system should not be too stressed.

-Tyler
 
Hi Tyler,

thatˋs a big one . i like those twins ,i allways want to build a dragboat or such twin . like to see when itˋs maiden run . many years ago i had a twin Octura Wing Ding with two 65 Rossi engine .

Happy Amps Christian
 
Very nice! About how many KW (HP?) will those motors make with this setup?
Conservatively on 6 cells it will be around 3kW per motor with low pitch props, but I suspect this will not be competitive.

More pitch and/or diameter and the load can easily double and the power system will push 6kW per side even on 6S although that's pretty tough on the batteries. So the challenge is to strike the balance of power and load on the batteries.

If I wanted to push the system up to the legal limit of 10 cells we are looking at a little over 10kW per side. Call it 25hp. At this point I may have to go to 1/2" solid carbon booms and a massive turn fin.

-Tyler
 
So 6 kw is about 8 hp, maybe like a pair of 90's. 10 kw is over 13 hp, nothing fuel powered can touch that.

Man there's a lot of power available with FE these days!
 
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Thanks Guys,

@Gilbert, the pump is from TCS Micro Pumps out of the UK. Be prepared for sticker shock, but these are fantastic little pumps.

@David, I have burned my fair share of lipos and boats up pushing the limits, the plan with this one is to be reliable and consistent. I won't be pushing more than 180A so the power system should not be too stressed.

-Tyler
Thanks, Tyler,

Like to know the pump model number you are using on this boat ?

Gilbert
 
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