props and electric motors

[frank carlisle]

Today I put a 12/5 Zinger on my electric Smoothie. It drew 200-400 Mah more than the 11/5 Zinger  I had on it before. After the run (6 mins.) the charger replaced 2856 Mah. So the run with the 12/5 Zinger used all but 844 of the Mah in my 3700 Mah battery. That would mean that the flight exhausted more than 75% of the battery's total capacity. I think.

So the diameter of the prop determines the draw.

Am I anywheres near close on this?

[Leroy Heikes]

Frank;
Increasing the load on the motor by increasing the size of the prop will increase the current draw. You are correct with that assumption.

[frank carlisle]

That's good to know Leroy. Yesterday was the most draw I've put on a battery yet.

It's astounding that one can know so little about something and still get it to work.

I feel really bad for all those guys who are planning to go electric but waiting till they have all the answers. I'd still be scratching my head and wondering. The plane and the set up are like having a textbook.

[Leroy Heikes]

I could say I learned that at Michigan Tech when I was studying Electrical engineering, but I actually learned that earlier when I was playing with an RC Truck. Kept loading up this sled with weight and pulling it with the truck until all of the wiring went up in smoke.

[frank carlisle]

Hands on beats theory everyday.

Leroy have you found out anymore about hosting a musciano contest at the Air Museum later in the year?

[RandySmith]

Astro Flight electric motor handbook

You may want to check this  book out, It will add  a lot to your understanding of electrics

Regards
Randy

[frank carlisle]

part #600--Electric Motor Handbook--$14.95.

Thanks Randy. I'll call tomorrow.