Electronics / Controllers: January 2009 Archives

I was trying to decide which servo to use in my project. I had some JR NES-241s lying around from my JR radio kit. They are nice analog servos.

I also had some E-sky EK2-508 digital servos which I had also just ordered.

I wanted to see what the speed difference might be between the two. The JR is rated at 0.23 / 60° arc while the E-sky is rated at 0.10 / 60°. But there are ratings and there are ratings.

So I fired up my servo tester and pitted them head to head in this very short video (1 minute; 5 mb). As you can see, the E-sky is considerably faster.

The e-sky is only rated to 1.0 kg / cm torque while the JR has 1.3 kg/cm. But I think that difference is negligible.

P1040184.MP4

I'm beginning a new project that uses micro servos. Here's a little table that I'm using to compare various options.

The conversion for torque from kg/cm to oz/in is to multiply by 14.7. So a servo with a torque of 1.0 kg/cm has an imperial torque of 14.7 oz/in.

Mini-Servos