madphil

Just finnished the paint job on my 41" falcon , i have give it a shake down before painting to check everything is setup ok .

I am running twin HET 1680's on 8s per side with twin turnigy 240 speedo's .with cut down x447,s all ready to run it tips the scales at 6kg with 4x 5000 4s lipo's ,its quick LOL

Goldenduff

Looks awesome. Had a thought regarding cooling. Can you run a closed water system to reduce drag of uptakes? Maybe passing the water through a air heat exchanger on the top of the hull? I'm a plane guy so sorry if it's a stupid idea!

madphil

No need i use a twin pickup in the rudder theres no drag and good cooling because the rudder is in the water most of the time

carlnoki

Looks great!!!!!!!!!!

where did you get the motors from?

thanks

madphil

Got them from HET they are EDF motors very high revving great motors we all use them in racing .

http://www.highendrc.com/index_ecat.php?cPath=31

madphil

I have now upgraded the motors to new 780KV (castle 2028's) these are big motors 112mm long x 58mm Dia and rated at 10hp each ( original motors look tiny at the side in 2nd pic ) i have changed to 1/4" struts and flex cable to handle the extra power ,

just waiting for my bigger 3 blade props to come then testing time again

tbaysal2000

Madphil, 20HP sounds really as Mad as your nickname

You have to share the vids and pls make sure to GPS that crazy thing. Redbull should really sponsor you with this.

srt10

My Feedback: (20)

You are a mad man!

madphil

i have been racing fast electrics for many years i have learnt its better to build an over powered boat and tame it down than try and make a slower boat faster ,
( with a cat you can raise the prop shaft and down size on props to tame it down a bit also much better run time and after a run everything is still cold )

most of the lads are screaming round on full throttle with the chance of burning there ESC or puffing lipo's in most cases i can overtake them on 75 - 80% throttle with 25% more run time and much less risk to lipo's, motors or esc;s ,


another spin off with an overpowerd setup you can get away with lower C rated lipo's ( 20c ) thats a big saving ££££££ $$$$$$$$

srt10

My Feedback: (20)

Wow, great points no one ever mentions...
maybe the CC2028 is the way for me to go in my Sprintcat 42"
I only need upper 50's to stay out front of the Gassers at my club being we are at 5200ft

785boats

I've slowly come around to that way of thinking too Phil.
Big powerful motor that can spin a prop much bigger than the boat needs. So with a smaller prop, but big enough to drive the boat to the speed you want, everything runs cooler because of the lesser amp draw. A given hull & setup still requires X amount of wattage for a given speed, but the motor can deliver that wattage more efficiently if it isn't being maxed out & running outside its efficiency curve.
Although here in Australia we can only run single packs, (no 2p setups for racing) so I still need to use 40C & 60C packs.

Great looking boat & set up by the way Phil.

Cheers.
Paul.

champion221elite

My Feedback: (2)

Sweet boat! What kind of speed is it capable of at say 80% and 100% throttle?

madphil

just got a mini GPS this weekend and fitted it my first reading was 67MPH thats under race conditions with a few boats on its not a very big lake think i could do better on a speed run corner to corner with no other boats in the way

martno1fan

What lipos are you using with these motors Phil im asuming your not on 8 s anymore ?.
Mart

madphil

No Mart its on 10s per side , at the moment i am using 4x Zippy 5800 30c twin 5s packs per side after a 6min race theres 25% left in packs and everything cold ,

martno1fan

I would think you should get a heck of alot more speed than 67 mph from it on a longer straight on 10 s per motor m8.
Mart

madphil

I think it will Mart but its set up for this years NADS supercat championships the race is 6mins with 10sec mill time i have my transmitter in heli mode with max throttle set at 80% that way i know i can easy do the run time and the last laps are still on race pace (in some cases my last laps are faster than the first laps depending where i am in the race )

madphil

Thanks Paul ,

i am lucky with paintwork my brother has an auto body shop
so i managed to sneek in at weekend and get it painted
its had :-
full 2K prime coat
flat silver ground coat
3 coats blue pearl 2K
3 coats blue/green pearl affect flip
yellow and decals applied
5 coats of high solid 2K clear then cured in low bake oven
wet flat with 2000 paper and buffed to mirror finnish

Got a another lightweight carbon falcon for next project hopefully there will be a few racing this year

Got RPM

I believe in buying the highest quality parts I can to improve both power and reliability. (Note I said highest quality, not necessarily highest cost.) While there is merit in 'over-building' the power units - there is a real risk to the ESC if one runs mostly at part throttle. Brushless ESCs will heat up plenty if run at part throttle, it is simply the way they work. With enough headroom this may not be an issue, but it is misleading to tell newbies that running at 75% throttle all the time reduces the risk on the ESC. I don't know about you, but where I race everyone is pulling max power for their classes - there is no way to build a boat which is competitive running at 75% throttle.

Too, some motors only reach their peak efficiency at high amp draw. The larger format Neus for example may need 200+ amps for maximum efficiency. That doesn't mean that they won't run well at lower power, just that to say efficiency is better at low amp draw is simply not always true.




.

madphil

[quote]ORIGINAL: Got RPM


That is the case over here with small mono hull racing classes up to 6s , you need the smallest lightest boats and everybody runs the same just hit full throttle when the race starts and steer round the course till the race ends or the battery puff's, you can't have too big motor it will have torque problems and be undrivable

With cats running twin contrarotating props there is no torque problems you can run an over powered setup with less issues .
the recomended hull size for my twin 10hp motors is 55" - 60" you should be able to run round on full throttle ok
so my boat is 41" thats a 1/3 less drag and weight on the water and i can only use 2/3 the power to get the same result;
it dont work out just a 1/3 but overall there is a saving with the setup .

as for esc most people size there esc's to the max if you only need 120amps on 4s they get a 120 esc so its on the limit why not get a 180 6s thats on top of the job

Got RPM

No puffing problems here - everyone runs either 2P or 6500 mAh packs.


I'm all over that idea. There is a hidden cost to buying the cheapest gear you can find...



.

vasek

My Feedback: (4)

You've got BALLS madphil we need a vid of these coke can size motors on 10S -please ?!

I'd take you to the lake any day LOL