Astro Motor Efficiency

[Green Machine]

So lately i took a tour of the Astro Flight factory and spoke with the Astro R@D engineering team.

We know that astro claims 90-95% efficiency when the motor is in its ideal power band of a specific high rmp depending on the wind of the motor.

This works great for RC airplanes etc which have tons of cooling and can be run constantly at the ideal rpm.

An ebike cannot be run at full throttle all the time.

But how much does the astro efficiency drop when outside of its ideal rpm range?

I am trying to get access to a dyno to test this very point. Has anyone already tested?

Has anyone verified that these motors are indeed 90-95 percent efficient when run fast? I know my astro bikes get hot to the touch when run fast....not a good sign in terms of efficiency.

 

[FFR Trikes]

Green Machine,

At the moment Astro is in the process of beginning full efficiency testing a few of their best-selling motors. We're expecting results back in the next couple of months.

I believe Matt still has an older dyno sheet from when Bob was in charge at Astro, I believe it was for a 6T Delta 3220. I know the motor peaked at 93-94%. From about 30% to 100% of the maximum motor RPM, they are very efficient.

Also, bear in mind that even though your motor is getting hot to the touch, these motors have very little thermal mass and shed heat more slowly because of minimal surface area. You could have a 3 lb 3215 running at 93% efficiency that is running fairly warm next to a larger, heavier motor that's running cooler because of its larger thermal mass and surface area, but at a lower efficiency.

With that said, when the right Astro is selected for the application, and it is gearing limited to the appropriate speed, and power limited it's suggested amperage at 90% efficiency, these motors will run all day at fantastic efficiency levels and nearly ambient temperatures.

Which motor are you running 3210, 3215, 3220? Which wind? Wye or Delta? What speed is it geared for at full RPM, and are you controlling its maximum amperage with a LRC or the like, if so, how many amps are you limiting it to? A couple small details make a world of a difference in how these motors perform.

We'll share the sheets when we get them back from Astro.

-Tommy