gooseF22
Posts: 662
Joined: 8/12/2006
From: Fort Wayne,
IN, USA
Status: offline
|
quote:
ORIGINAL: erazz
quote:
ORIGINAL: gooseF22
A small prop on this one is ok because it has little drag. I was using a proven system. I ran the power system 6S 2500Kv on the nitrocat before just to test it. it was delivering around 800 watts consistently when warm and midrange on batteries. with the higer voltage, it unloads superbly, but that airframe is draggy. It would scoot about 90mph. You could tell the static thrust just wasnt quite what was needed but it would still climb straight up. If I were gonna try to make a total screamer, then up the motor to a 1600 or 1900 kv motor and go 8S, but I dont know how you would get 8 btts in there, but the power difference between the two is pretty big, and wires get hot fast above 1000 watts.
Hi Goose,
I was thinking of going along the same lines.... I have a Kontronik Fun 600-18 (kv=1800). I was thinking of using a 8S A123 battery. This would unload to 40,000rpm in the air with a 5.5x4.3 prop. My guess is that the system can take it but the prop seems waaaay too small to produce any usable thrust.
Do you have any suggestions as to what battery and prop could work with a plane like this and the Kontronik?
erazz
Ya,
that prop is too small.
with 1800 and 8S, find a Cam prop, 6x6, or very gently cut down a 7x6 cam series.
I am now running a cam 7x6 on my 1600 8S nitro cat and it hauls the mail but doesn't overload the batts.
8S may be too much for this setup. A 6S with 1800 and you could run a 8x6 apc and haul the mail. my 2500 is running a 6x5.5 and I will trim it by sanding the tips. we got 10 mph out of the cam prop for less load than the apc or MA.
best guess is 120mph now, so with that wattage on the deamon, it should go 130 plus or so, its easlily 1/2 the weight and 1/2 the drag. When A123's unload, they unload big because the voltage depresses so much under high load, when it unloads, it really picks up speed. You can really hear it accelerating on the down line. Loaded the 8S dprepesses to about 18.5 to 19 volts from over 28, so as it unloades the battery amperage at speed just a bit, the motor really picks up rpm. by dropping to a 7 inch prop, I really picked up rpm. I was worried about static but it took off in 50 feet versus before it was about 40. no big deal. It still climbs like a rocket.
Sorry guys Im in the middle of Jet season, so the deamon is waiting. I will get to it soon.
< Message edited by gooseF22 -- 6/25/2008 6:25:36 PM >
_____________________________
Goose
Team Fromeco
|
Printable Version
All Forums >> RC Airplanes >> Extreme Speed Prop Planes >> RE: (Something Fast?) Delta Build Thread 
RE: (Something Fast?) Delta Build Thread - 
