1st Build

[RandyatBBY]

I usually set up the boat with the COG between 26% and 30% from the transom. You can put anything any whare you want as long as you end up with this ballance.

[chris holley]

iam about 30%??? but if its not right then tough luck to me lol.

[RandyatBBY]

iam about 30%??? but if its not right then tough luck to me lol.

You should be able to move stuff to the rear. what will happen is the bow may not get loose enough. Some times I will put in lead weights in the rear to achieve this.

[chris holley]

yea iam using nimh cells so there is waight somewhere

[chris holley]

a few pics so far, carbon rods mount and servo mount.





still a bit off work, shaft which i have to get quite a long one though, rudder mount and arms, and water outlet.

[chris holley]

one more

[Rich]

It looks good so far, keep at it. Randy is right, you can always add some weight in the back if you need it.

[chris holley]

yea ok thanks

[siberianhusky]

if you are using a solid shaft then it is a sub surface drive, you do not want the prop way out the back in that kind of setup, you want the drivedog about the transom of the boat.That 10% rule only applies to a flex cable surface drive system.You will need to run smaller props as they are completely under water all the time, surface drive the prop is half out of the water while running.

[chris holley]

Ok well its a solid shaft, i dont use the dog type prop just the 4mm screw type.

So how far out do i need the shat to be if its straight from the motor out off the transom.



centre off VEE close to bottom

[chris holley]

if he shaft is in the VEE, where could i put the auto bailer?

[znus]

I like these old school builds! Really, brushless and Lipos are the way to go but when you just wanna play around regardless of weather and waves there's no point with boats doing 100+ km/h. I'm having good fun with my old 700 mm Joker hull with a Traxxas exv-2 and Titan 775 engine. I'm using a solid axle of ~320 mm, lowest possible placement of the motor and surfacedrive (solid axle sticking out - no stinger) with a Graupner 45 mm prop. It's capable of 40+ km/h. I also run a toy ABS-hull with twin Robbe Super 600 motors (on 2s Lipo). So far I have 45 km/h on the GPS on it. Brushed is fun! I think the speed is just perfect

As the others already have said - don't worry about motor placement. The longer the propshaft the better angle of surface drive you get. It will have negative angle but it works pretty good anyway. I use a stiff motor shaft to axle connector when glueing it all together (motor mount, axel support) and then switch to something which will allow some play and vibration. I guess you already know this

Anyway, that's a big hull and why not going dual counter rotating 700 for some good brushed fun? Don't forget some brushed motors have timing "built in" and shouldn't counter rotate. If you go dual you need 0 timing motors.

/z