David Kingston

[VansRacing]

I was looking for David Kingston or anyone who runs electric outboard and electric O/B retro kits & etc.

-Carl

 

[Mike Hughes]

Carl

What do you want to know? I use to run the electric tunnels back in the day. I just built a new tunnel for Dick Crowe last year or so. Weighing in at 12oz with a sealer coat on. I want to build a new one for the SAW at legg in the fall for Dick. If I have the time.

Mike

 

[VansRacing]

Mike,

We should talk about this some day. Does NAMBA offer a class for the electric O/B tunnels? It probably would be cool to see how fast you could get a electric O/B tunnel to run.

Carl,

 

[Kevin Whitehead]

How about this-

NAMBA Electric straightaway records:

OPC Tunnel Larry Larson 11-02 45.29 MPH

Assuming that this 2 1/2 year old record is still standing (NAMBA get a little behind sometimes).

KW

 

[Kris Flynn]

Carl,

David and I are running in the low 40's (GPS) consistanly with a 'heat racing' setup...he is running a Hacker B50 8XL and a lawless and a Villain S1 and 3300mAh cells

I am running an own design tunnel 8XL lawless and old 2400mAh cells

Larry's record was done with a home built Starks tunnel, a very good effort I think!

Kris

 

[Mike Hughes]

Dick had the boat I built him at 54 when it blows off. I jsut need to build one to put all that power to the water. Tunnel racing in electric is not as popular as the other classes. So there is not a lot of devolpement in the hull. Usually guys just run the nitro hulls. They are a little on the heavy side once you get the Cg right and all the cells in them.

Mike

 

[drobie]

Mike,
We should talk about this some day. Does NAMBA offer a class for the electric O/B tunnels? It probably would be cool to see how fast you could get a electric O/B tunnel to run.  

Carl,

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The NAMBA electric Nats in June have decided to run the class on 700 motors (and 12 cells) this year. Reason being that running electric O/B unlimiteds (brushless) wasn't widely supported.

On the other hand, there are a few clubs around the country that are having success at reviving the class by going to a sealed can 700 brushed motor.

 

[VansRacing]

How about this-
NAMBA Electric straightaway records:

OPC Tunnel        Larry Larson             11-02                    45.29 MPH

Assuming that this 2 1/2 year old record is still standing (NAMBA get a little behind sometimes).

KW

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45.29MPH ...is a good electric run. I am going to try to pull up the NAMBA records and check it out.

Carl,

 

[David Kingston]

Carl,

had to subsrcibe to this forum. You can get my on RR forum mostly but now i am here i might as well chat on both.

So you are interested in an FE tunnel.

What would you like to know.

Kris is right we are running in the 40mph bracket. I think if some one had a serious crack at the OPC SAW record this year it would fall. The earlier record to my knowledge was set with 2400 cells. I think Larry set the first record with a hacker 7XL and 645 prop the next year was a 8L and 438 prop.

let me know where i can help

David

 

[VansRacing]

David,

I have finished a drawing for a 25" Tunnel that is along the same design line as my Lynx 3.5cc Tunnel.

This "Hacker" engine...is it a conversion kit that someone is building?

Tell me this, what is your ready-to-run weight for the electric O/B?

Carl

 

[jayt]

Larry ran a Stark's balsa/ply hull to set the record; the plans are in RCBM's store. It isn't the best hull but it worked. Dick tried to best it last fall but couldn't put together two decent runs - the boat blew off too easily. It will take a specially designed SAW hull to do much better - the power is there, my 12-cell cat ran 74.3 mph. All that weight in the rear, a tunnel shaped to aid blow off......there are known "secrets" to keeping a tunnel on the water, they just aren't applied to FE boats very often......

 

[Mike Hughes]

Not to mention the Starks hull Larry is running was designed more than fifteen years ago. He was running it when I got into boats. Back then we ran 05 brushed mod motors on cut down K&B leg with Hughey single motor reduction. The Hacker is a brand of brushless motors. They are mounting them with direct drive to the cable. The RTR weight should be as light as possible. The packs alone will add 1.5 lbs. A lot of people have try to adapt the nitro boats with electic outboards. They do not proform that well. The boat I built for Dick came in at .75 lb. If I could of got it lighter, I would of. Had to have some strength in it. IT works great as an oval racers. Not the best for SAW.

Mike

 

[David Kingston]

My tunnel is lots heavier than the norm.

I painted it and dashed it up to look the part and because of that there is extra weight. The hull with radio is 1Kg and with batteries (12cells) on the water it comes in at 2.6Kg. I still manage to get 40Mph oval trim by having a good setup and running the boat loose although it runs like it is on rails.

Its a grim racer thing....

My setup is as follows

HAcker 8XL brushless motor

Lawless 3.5 outdrive

K&B stub shaft

Home made motor mount to adapt the electric motor onto the nitro leg.

x438, x437/3, x637 props from octura.

12 3300cells.

Hacker 99 Electric Speed Control (old version)

Hitec radio and receiver

The hull is a villain s1 from grim racer.com

I have just completed making shorter sponsons and a lower CoG tub section of another tunnel this one is slightly shorter and heaps lighter. No paint and all very light material used in the hope i can keep it on the water at over 45mph 12cells.

IMO i would not build a tunnel shorter than 25 -26 inch long as you cannot keep it on the water with todays power. My nitro villain converted works great as an electric boat. There are some things that i have changed in my new design more to suit personal preference and fit electric gear into it.

Check out

finedesignrc.com motors page for HAcker

this might clear things up

David

 

[T.S.Davis]

The NAMBA electric Nats in June have decided to run the class on 700 motors (and 12 cells) this year. Reason being that running electric O/B unlimiteds (brushless) wasn't widely supported.

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Well sort of. The organizers didn't decide. The racers formed a gentlemans agreement between themselves to all run 700 motors. No body is in a particular hurry to plop their brushless setup out there for a good drenching. They should be a hoot for oval racing on the 700 cans.

 

[Grimracer]

I still keep thinking that weight is over rated for FE racing. Being weight careful is a must but could be overrated.

I went through the exercise of building a FE tunnel this winter and learned a lot. The boat is optimized for the cell count and the hull true and ready to rock.

Im sure when testing starts info will start to come out..

Grim

 

[David Kingston]

Grim

as i said my boat is heavy for electric and i am robbing myself of speed.

The lighter boat that i am making is just as strong. I used balsa frams and stringers and it is sheeted with 0.8mm ply on top, 1mm on the sheer and bottom

i'll keep you posted when it hits the water.

 

[Grimracer]

Without question a boat (any boat) can be to heavy.. Im just thinking that we spend to much time on the aspects of lightweight and not boat design to optimize performance.

Grim

 

[VansRacing]

I was thinking along the same lines as Grim. I have been working on a 25 inch tunnel. I really don't know that much about electric boats but I have always wanted to try it. You know me, I am going to try to build it from composite in the end.

I can build a 28-1/2" composite boat under 2 pounds and it still be fairly tough.

However, a 3.5cc built at this weight will get you into more trouble with wind than it is worth if you were to try to race it.

I am hoping that this method can be used to build a super lite 25 inch mini tunnel from glass and when I add this 1-1/2 pounds of batteries you say I am going to need back to it, maybe it will still float! LOL

This will be fun.

Carl,