I've been getting a lot of questions at my flying club after doing a dual powered combat Gremlin, mostly out on the field, about what size motor, battery, and ESC choices. so I wrote an article in our March DVRC newsletter to help explain in simple terms the basics of electric flight.
Then I followed up with a circular calculator for field use in our most recent May newsletter and a download if anyone else is interested.

http://www.dvrc.org/index.htm

Mike - downloaded the circular slide rule - printed and assembled.
There are probably way more uses intended in your design than those I can figure out myself.
I was looking on your club web site for the instructions for the slide rule and didn't find it.
I would guess that you did write up something for your club members - maybe in one of the newsletters?
Could you point me to it, if it exists.
Thanks,
Walt Bankes

Originally Posted by wjbite

Mike - downloaded the circular slide rule - printed and assembled.
There are probably way more uses intended in your design than those I can figure out myself.
I was looking on your club web site for the instructions for the slide rule and didn't find it.
I would guess that you did write up something for your club members - maybe in one of the newsletters?
Could you point me to it, if it exists.
Thanks,
Walt Bankes

Walt;
The instructions are buried in the latest newsletter:
http://www.dvrc.org/newsletters/2010/0510/0510.pdf

Hey Mike, fancy meeting you here!

I've been a member of DVRC since 1993 and always flew electric power. Back in the early days I was considered a bit of an oddity for my E-power. It seems that I didn't get any respect until the planes that I was flying began to out speed the wet powered models. That was at our old field and the atmosphere around the club has taken a complete change since then, all for the betterment of the club.

Anyway, what 'm trying to say is it's really refreshing to see your work done to try and educate our members (and others) on electric power. Great job on your articles and publishing the E-power wheel. I hope that it takes off and gets a few more interested. Thanks for sharing and keep up the good work Mike!

Greg Gallegos

Greg;
how do you get this posted on the front page so people will see it?

To get it posted on the front page of this thread you'll have to ask the thread starter, Ron van Sommeren, if he will edit the 1st post to include your jewel of a calc.

If it was my work I'd do that AND start my own thread on this. The simple math required for this couldn't be made more simple. It really is great work you've done and worthy of it's own thread.

Originally Posted by Ron van Sommeren

Mike, have you started your own thread? If so, I will add that discussion to my first post as well.

Prettig weekend Ron

Ron;

don't know how to; don't know if I should...
I just thought I'd share my work with others.
Have you looked at the articles and the wheel to see if it's useful to others?

Originally Posted by MikeW9

Ron;

don't know how to; don't know if I should...
I just thought I'd share my work with others.
Have you looked at the articles and the wheel to see if it's useful to others?

Mike by all means start a new thread. Your wheel is super easy to use and will help many. Please do start a thread.

To start a thread simply push the button.

How about Martyn McKinney's spreadsheet, propeller23.xls

It can be found here:
https://www.rcgroups.com/forums/show...postcount=1675

- Roy

This is excellent, thank you for doing such a great job.

Hello,
Moteur_calc is a javascript calc to define the electric propulsion for a plane.
You have just to enter : flying weight, wing area, flying type and cells number.
On line (no download needed), you have all propulsion elements.
Please go to my blog (sorry, only in french ) :
Modelisme by geeby22
and clic on : "Calcul d'une propulsion électrique"


Sorry for my poor english language !
Geeby

Originally Posted by geeby22

Hello,
Moteur_calc is a javascript calc to define the electric propulsion for a plane.
You have just to enter : flying weight, wing area, flying type and cells number.
On line (no download needed), you have all propulsion elements.
Please go to my blog (sorry, only in french ) :
Modelisme by geeby22
and clic on : "Calcul d'une propulsion électrique"


Sorry for my poor english language !
Geeby

Thanks Geeby! I just tried out the calculator and it seems to be giving me odd results. The recommended power setup is way Under Powered.

This was for a 70" 3D HobbyShop Slick. Here is what I entered. 3D flight, 4 kg, 61.3 sq. dm and 8S.

The results were 1350 W. That is way to low for 3D 1800 Watts to 2200 Watts is what I expected.

Battery capacity was fine but discharge rate was off. It recommended a minimum of 15C where I don't think I would fly with anything less than 20C on that setup.

Propeller was also off. It recommended 15.8 x 7.8. That will not move the plane. The smallest prop for 3D for a plane this size would be an 18x10.

Originally Posted by geeby22

Hello,
Moteur_calc is a javascript calc to define the electric propulsion for a plane.
You have just to enter : flying weight, wing area, flying type and cells number.
On line (no download needed), you have all propulsion elements.
Please go to my blog (sorry, only in french ) :
Modelisme by geeby22
and clic on : "Calcul d'une propulsion électrique"


Sorry for my poor english language !
Geeby

Bonjour Geeby
Tres bien ton calculateur ... simple ... pratique
Sur le blog il y a des téléchargements.
Scorpion Calc last version = 3.37
Regards
Louis

Bonjour Louis,
Je vais mettre à jour mes téléchargements de tes programmes de simulation dans les jours à venir (j'ai mes 3 petits fils à la maison ).
Ils fonctionnent merveilleusement bien et je les recommande à tous.
@+
Geeby

Originally Posted by 3D-Dabbler

Thanks Geeby! I just tried out the calculator and it seems to be giving me odd results. The recommended power setup is way Under Powered.

This was for a 70" 3D HobbyShop Slick. Here is what I entered. 3D flight, 4 kg, 61.3 sq. dm and 8S.

The results were 1350 W. That is way to low for 3D 1800 Watts to 2200 Watts is what I expected.

Battery capacity was fine but discharge rate was off. It recommended a minimum of 15C where I don't think I would fly with anything less than 20C on that setup.

Propeller was also off. It recommended 15.8 x 7.8. That will not move the plane. The smallest prop for 3D for a plane this size would be an 18x10.

Thanks 3D Dabbler,
My purpose was for middle plane. I will take into account your remarks for extrem 3D fly... with Abott formula the traction is too low ,)
However, the motor power is a "marketing" value, and I prefer use the weight.
For the discharge rate, it's the min value, and for reliability and durability, you take advantage to increase this value...
In any case, I will increase the power for 3D fly...
For the propeller, the pitch depends of motor kv...
@+
Geeby