What is the difference between coreless and brushless servos?

Coreless motors are manufactured with a rotor attached to a  commutator plate.  They are lightweight and have very low starting inertia, which provides maximum acceleration with relatively low power consumption.

Brushless motors are comprised of magnets and a spinning armature. They are more efficient than coreless motors, but they have a bit more starting inertia. They generally provide very low power consumption and have a longer lifespan than coreless motors.

Both servo types are very efficient these days, in reality your decision should be based more on personal preference, coreless servos are less expensive and can provide the same if not better performance than brushless servos. Brushless servos on the other hand are more efficient and could potentially last longer, but this comes at the expense of higher cost.

Would a coreless servo work well on a large machine, such as a 700 class heli?

Absolutely! One of the most popular servos manufactured a few years ago was a coreless servo. Bert Kammerer himself flies coreless servos on some of his large 700 and even 800 class helicopters. It would be wrong to assume that because you have a large machine you must get brushless servos.

Do I need to run your servos are high voltage?

Yes you should! Our servos were manufactured for high voltage operation. Even though they will operate well at voltages as low as 5.5V, we recommend running at least 6V with 8V being the ideal voltage of operation.

I plugged my helicopter in and one of my coreless servos didn’t boot up, why?

This situation is common when using some BECs. Basically our servos require stable voltage in order to boot up, some switching BECs power up at low voltage and increase their voltage over a certain time frame. If the servo doesn’t get enough voltage, it simply won’t boot up. The reason why only one servo doesn’t boot up is because it is perhaps the last servo in the power up sequence determined by your flybarless system.

Although annoying, this particular issue is not one to be worried about, simply make sure all your servos are powered up before every flight. If you encouter this issue, simply unplug your battery and plug it back in, once all servos power up you are safe to fly.

You can eliminate this behavior completely by using a faster switching BEC, such as those made by Western Robotics or by using a 2 cell lithium polymer battery.

Can your micro servos operate at 8.4 volts?

Yes they can! We specify a maximum voltage of 7.4 volts on our micro servos simply because their motors being so small, running voltages above 7.4 can shorten their lifespan. However, they can certainly tolerate voltages up to 8.4 without issue.