Chris Channon Posted July 10, 2008 Share Posted July 10, 2008 I was bought an Alley Cat look a like for Fathers day, nice little aeroplane, it was just the bare airframe, ie, no motor, speed controller,nothing.It is the prop version, prop's supplied. So i bought a 3200kv out runner, ( as per the instructions)35 amp brushless speed controller,1350 3s li-po pack.All assembled, i get just about one minute's run time and the li-po is hot, the bec cuts in , i have charged the pack using a balance charger but still only get just over one minute run time !!!!Help!!!!!Chris.c Quote Link to comment Share on other sites More sharing options...
birdy Posted July 10, 2008 Share Posted July 10, 2008 If you have a watt meter check the amps pull. What prop is it, and what is the lipos C rating? If you are pulling something like 25 Amps from that lipo, your overdoing it abit! Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted July 10, 2008 Share Posted July 10, 2008 A 3200 kv motor is a very high rpm motor for use with a prop unless used with a gearbox. What size prop was supplied. Quote Link to comment Share on other sites More sharing options...
winchweight Posted July 11, 2008 Share Posted July 11, 2008 I'd say your lipo is a bit of a light weight too. It's quite a low capacity for such a demanding motor and esc setup. Quote Link to comment Share on other sites More sharing options...
Chris Channon Posted July 15, 2008 Author Share Posted July 15, 2008 Hi all, looking at the prop, it looks like a 4 x3 if it was a glow prop., I have to re-think the setup as the esc blew out all of the magic smoke on the last run, getting expensive this electric flight lark !!!Getting really confused now, i was told that the motor i have is ideal for D/F , not for direct drive, so surely if i use a fan then the motor will be pulling a lot more amps than a little prop?Confused againChris Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted July 16, 2008 Share Posted July 16, 2008 Not really it would depend on the diameter of the fan, if its only 50-60 mm then it will be a smaller diameter than the prop, I have a couple of small EDF's around 50mm using 4,000 kv motors and they pull around 20 amps.a 1350 mah battery is very small for this application hence it's getting very hot and probably cutting out after a min due to the LVC cutting in.Just for interest I ran a 3200 kv motor with a 4.5 x 3 GWS prop in the Drive Calc simulator and on a 3s set up it predicted it would pull 20 amps, so I would say that it's the battery which can't deliver the amps. Not sure why your ESC failed though. Note an APC 4.5 x 4.1 prop increases the current draw to 25 amps, so it would be good if you knew what the prop is as a small differnce in size can give a big difference in the amps drawn. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.