help and suggest plz!
09-19-2009, 05:39 PM
#1
Junior Member
Thread Starter
Join Date: Nov 2005
Location: Ranchi (India)Jharkhand, INDIA
Posts: 24
Likes: 0
Received 0 Likes
on
0 Posts
help and suggest plz!
i ve just finished designing an airplan, wing span- 40" chord- 8", fuselage -30" . i m not able to figure out which engine size to use,
weight estimated to be in range of 700gm to 1kg (including electronics and engine )
i mean wether i shud use .15 engine or some electric motors.
if you suggest a motor then what size of motor (or name) i shud use.
sorry if i sounded stupid but seriously , i have never been into electrics and have no idea abt that field..
weight estimated to be in range of 700gm to 1kg (including electronics and engine )
i mean wether i shud use .15 engine or some electric motors.
if you suggest a motor then what size of motor (or name) i shud use.
sorry if i sounded stupid but seriously , i have never been into electrics and have no idea abt that field..
09-21-2009, 06:40 PM
#2
Senior Member
Join Date: Dec 2002
Location: Chattanooga,
TN
Posts: 2,198
Likes: 0
Received 0 Likes
on
0 Posts
RE: help and suggest plz!
About 100W/lb is adequate for leisurely flight (for aerobatics 150-200W/lb is the norm)... so reverting to this antiquated imperial measurement you are at 1.5-2.2lb... thus you'll need 150-220W of input power.... 300W would get you very spirited performance. Most decent outrunners of 70g-80g can cope with 200W+... so might I suggest something like a 70g Suppo A2217K/8 (1100Kv) which could spin a 10x6 GWS HD at 9000rpm (50mph pitch speed), getting you 1135g (40oz) thrust from 21A/220W.
That gets you at least 100W/lb... and just as importantly a thrust to weight ratio of better than 1:1.... more than enough for decent flying. Make sure you get an ESC rated for at least 25A and a 3s Lipo or 10-cell NiMh pack capable of coping with 25A+ too.
That gets you at least 100W/lb... and just as importantly a thrust to weight ratio of better than 1:1.... more than enough for decent flying. Make sure you get an ESC rated for at least 25A and a 3s Lipo or 10-cell NiMh pack capable of coping with 25A+ too.
