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Sammus
RC-Monster Titanium
 
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Join Date: Jan 2008
Location: All over Australia.
07.03.2009, 09:14 AM

its not the brakes that is the problem. Go and do some jumps. You will notice sometimes if your throttle isn't perfect, the nose might dip a bit in mid air, and to correct it and land on the landing ramp smoothly, you blip the throttle just a tad and the gyro effect brings the nose up a little to stop it from nose diving.

Using a car esc, this is possible, because they allow the motor to spool up quickly enough to give a fast rpm change like that. This fast rpm change is when peak current is drawn - on the road in a truck castle measured peaks in excess of 800A. These peaks arent visible on eagle tree etc because they are only momentary, but as far as the electronics are concerned, they still happened. The FETs in the car escs can handle thes momentary rushes of current.

In an aeroplane or a heli, you dont want the prop to spool up to full speed in a fraction of a second, so they limit how quickly in can spool. in the same jump scenario above, you blip the throttle to bring the nose up and you've hit the ground on your roof before the rpm increases significantly. This way the Air escs can use much lower rated FETs because they dont experience the extreme current peaks that car escs do. This is also why they dont cog, because they are designed to spool up slowly, because thats what you want in aircraft. this also has the effect of much lower peak current draw.

Last edited by Sammus; 07.03.2009 at 09:16 AM.
   
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