I have built an airplane capable of 3-D performance. It was suggested by the designer to use servos that have at least 60 in/oz of torque. I purchased four servos to meet that need. Now I find, when all controls are used, such as during a spin, the current draw through the RX is so high it makes the servos glitch to the point of a possible crash. How do I get past this concern? Power distribution ? what can be done ? What do the people use that fly quarter scale type planes ? How do they get around this "high current" concern? Any help at all would be appreciated, thanks.

Try looking into a UBEC. This replaces the on-board BEC within the ESC. You should be able to get one that will supply enough current for all servos working at once.

Thanks for the quick response. It's is actually happening to my friends airplane, so I will tell my friend to do that and let you know if it doesn't work. Thanks again

What brand of radio is the problem with?

Greg

Yes, jzrf6c is right on the money. The built in BEC in the speed controll is not meant for the high loads these larger servos can draw. Depending on the current draw of your servos you can can use a UBEC as he mentioned (probably good up to about 5 or 6 amps) or a regulator which can be sized as needed.

The radio actually doesn't have a problem, it is the servos that are having the problem. My friend is going to try your suggestions and let me know what happens. You guys are probably right though, thanks for the assistance

The reason he asked about the radio is because high servo load can cause the available voltage at the receiver to drop below a threshold value and the receiver then "locks out" causing loss of control. Of course when the servos stop moving the voltage goes back up, the receiver starts working again and the cycle repeats making it appear like it was a servo problem. Some receivers are more prone to this issue than others.

Oh I see Jezmo, thanks for the info. I never knew that!