R/C Electric Motor Calculator

[Colonel Klank]

One of our club members asked me what was the best way to find out which electric motor was suitable for what size plane. I told him that I would make up a cross reference chart for that purpose. That quickly gave way to an Excel Calculator where you simply plug in a couple of numbers, and out pops your answer.
The attached PDF is calculated for an E-FLite Power 46 motor and the numbers came out pretty close.
Those of you that are smarter than me please look at the numbers and tell me if I went stupid anywhere. I will also clean this design up a bit if it gets some interest.
Thanks.
Patrick

[wizard]

This will help a lot of folks. It seems that every manufacturer uses a different system to label their motors and the confusion is extreme for many. Now if we can just get someone to go through and plug in the numbers for every motor out there and make a chart.........Well I can dream, can't I??

[Colonel Klank]

Here is a screen shot. Max made some changes to speed up the site, so just click on the image to see a bigger view.

[wizard]

All your formulas look correct.

[Colonel Klank]

	Quote: Originally Posted by wizard
	All your formulas look correct.

Thanks Mike. It looks like if you use this calculator, your plane will NOT be underpowered. The calculations I came up with may need some tweaking. Please let me know if I need to change the scaling factors.
Thanks.

[wizard]

The small screen shots are part of the new site improvements. The thumbnails are smaller but you can click on them to get a larger image. Max switched to smaller thumbnails to speed up the site for those members on dial up.

[Freddy Warbird]

	Quote:
	Max switched to smaller thumbnails to speed up the site for those members on dial up.

Thanks you for that!

[Colonel Klank]

Stan, Les, Kent, Jamie? Have you had a chance to compare with your setups?

Thanks.

[SlowHuck]

	Quote: Originally Posted by Colonel Klank
	Stan, Les, Kent, Jamie? Have you had a chance to compare with your setups?

Well, yes... and it appears I was about to smoke a ESC. Now switched with a bigger one.

[Colonel Klank]

	Quote: Originally Posted by SlowHuck
	Well, yes... and it appears I was about to smoke a ESC. Now switched with a bigger one.

Whew! We saw what happens when too small an ESC is hooked to a big motor two weeks ago! Let me know when you plan to maiden the Icon.

[SlowHuck]

	Quote: Originally Posted by Colonel Klank
	Whew! We saw what happens when too small an ESC is hooked to a big motor two weeks ago! Let me know when you plan to maiden the Icon.

I'm gonna use some tax refund $$$ for another AR6000 and a fresh 3C 2100Mah LiPo.
(don't really trust the old ones much). I still want to log some sim time before taking that performance leap. I also need to do a little surgery on her (to get the battery position more forward).

Spent some time today kickin' up the throws and fiddlin' with the mixes on SlowHuck today. Look out!

[Colonel Klank]

I took the actual performance figures from the FG Foamy with a Hacker A20 - 22L and made some refinements to the calculations on the sheet. Please review the numbers and let me know if they look OK. Thanks!

[Chango]

hi all. Good work, but I see that most people miss the point that for 3D fly watts isn't all about, for example: you can have a lot of watts from a motor with a hight kw an a small prop with hight pitch, that isn't very usefull... the most importan thing is thrust and pitch speed. Then the diameter, the pitch of the prop and the voltage of the Lipo give you the current into the motor and power in, that's always less than out. Here comes the heat generated... And 'cose the motor are AC not DC the calc is a little diferent there.
Lots of watts are ok, but with lots of thrust.
Try play with Motocalc8 is a nice calculator.
Sorry for my english, I don't write very well