Head Speed/Battery Calculator for Windows

[BruceW]

With all those new helicopters everybody got for Christmas it seems there might be a need for a new tool to calculate head speeds to go along with the motors, batteries, and pinions. For the past month or so I've been beta testing a Windows based head speed calculator over in the Mikado forum (thanks everybody) and figure its time to pass it on to anybody else who may want it.

Head Speed Calculator (current version v1.0.7) - http://brucewsb.s3.amazonaws.com/Files/HSCalc.zip

There are several unique features that make it more flexible than some of the web based versions and it even has a battery capacity calculator along with flight time estimator. There are more features to come, along with a large range motor database that will help you cross reference motors and narrow down motor choices based on operating criteria. I'm even looking at porting this to the Mac if there is enough interest.

For now, here is a list of the current features in version 1.0.7.

Basic tab (head speed calculator)
1. Choose battery cell count and if its Lipo or A123
2. Choose motor and get documented KV rating or type in known KV
3. Get main gear teeth for known helicopter or type in specific tooth count
4. Efficiency slider allows adjustment from 70->100%
5. Pinion slider allows adjustment from 7->30 tooth count. Later on you will be able to choose a pinion range based on manufacture range
6. Display dynamic gear ratio of main gear to motor pinion.
7. Calculate and display target head speed, motor RPM, nominal voltage, nominal volts/cell from mentioned parameters
8. Slider for adjusting cell voltage for Lipo or A123 to simulate head loading conditions
9. Variable voltage slider also allows you to reverse find cell voltage from total voltage.
10. Reverse find other variable parameters from fixed parameters. Example would be to find motor efficiency or cell voltage from known head speed.

Battery tab (capacity/time calculator)
11. Type in known capacity of battery in Ah or mAh
12. Use slider to show used or remaining capacity as a percentage. You can also type in the percentage of used/remaining capacity to cross compute.
13. Green progress gauge is ranged from 0->80% to show safe limit of usage
14. Calculate flight time statistics
15. Enter used Ah's for a given time and get discharge rating
16. Estimated flight time is displayed as a function of discharge rating and used capacity from the slider

More will come with time and effort. This is just a tool I created to give back to all the users on the Freak for all the help I've received along the way.

The history of progression can be found in the following thread:
https://www.helifreak.com/showthread.php?t=52607

Enjoy,
Bruce

[OICU812]

Bruce put a ton of work into this little handy program, thank you for all your efforts on this Bruce! You get a big star on the fridge!!!

[franky92]

works like a charm! thanx! it's going right on my field laptop!

[BruceW]

Originally Posted by OICU812

Bruce put a ton of work into this little handy program, thank you for all your efforts on this Bruce! You get a big star on the fridge!!!

Thanks Shawn and thanks for letting me keep it in the Mikado forum for a while.

[AARNAL]

Hey.- Thanks Bruce, is the best application calculator for helis I've seen. Real close to my present setting and it will be a big help when I do governor set ups.

Thanks again

Big Al

[veegor]

Thanks Bruce for your time spent on this version really nice.

[hommer75]

Looks very good. Sadly I'm missing the option to use it on my Hurricane which has a double gearing 15:42 and 20:61. Perhaps in the next version???

[MarkD]

Handy application Thanks for the effort put into creating it


OK Own up. Who else tried to close the jpg view window down with the jpg's image red X

[tz250w]

Originally Posted by franky92

works like a charm! thanx! it's going right on my field laptop!

Hey, why does a 15 (soon to be 16) year old need a field laptop???

Oh, and thanks for sharing Bruce. Nice work!

[MarkD]

Originally Posted by tz250w

Hey, why does a 15 (soon to be 16) year old need a field laptop???

So you can faceyoutubebook your mate 10ft away from you.:p

[aucmax]

I just wish there was a feasible way to mathematically predict the correct Idle-up throttle V or possibly a U curve when at center-stick (zero blade pitch, bottom of curve and target HS RPM at this point is known) and 100% throttle equals (+ or - X degrees of maximum blade pitch-linear pitch curve) that would ensure a constant headspeed throught the throttle curve until 100% throttle is achieved. This would of course require a complex set of variables, at the very least which may include heli weight, blade/motor/battery characteristics that are integral in the determination of lift force. I watched Bobs' Throttle Curve Video and this particular determination, as he describes, is a matter of trial/error and tweaking. Science fiction, heh? Or perhaps not?

[BruceW]

Originally Posted by hommer75

Looks very good. Sadly I'm missing the option to use it on my Hurricane which has a double gearing 15:42 and 20:61. Perhaps in the next version???

I'll add an option for using a second gear to the list of future features. Do you know of any other helicopters that use a double gearing system?

[hommer75]

Some nitro birds do, but I can't think of any other electric heli that does.

[franky92]

Originally Posted by tz250w

Hey, why does a 15 (soon to be 16) year old need a field laptop???

It's an OLD laptop used to download data from my eagle tree.

[th3tick]

Any chance you could hook into this database:

https://www.helifreak.com/showthread.php?t=51569

for your motor data? It might just then turn into a query on demand to update the local data. Of course, with that much data, the motor selection dropdown probably needs to be split into brand and model...

Just a thought,
John

[BruceW]

That is a good source of data. It shouldn't be too hard to import it and I agree that a better selection method will be needed with that many items in the list. The motor tab is the next piece I plan on working on so stay tuned.

[SpeedVision]

Awesome Calculator! Thanks for all your efforts, Bruce!!!

Am I lazy or would it be nice to have a slider for throttle percentage as well? This might help dial in the target pinion size... A suggestion for range could be 75-100% to inhibit anyone from running too far below the efficiency range of most motors...

My 2 cents... Thanks

[BruceW]

Thought about adding a throttle slider a while back but I've found that the throttle input to the ESC is not necessarily linear and starts flattening out above 90%. Also, governor mode on the better ESCs is close to calculated head speed when run around 85% (i.e. Jazz ).

You'll need a tachometer to get more precise but you could just use the 'efficiency' slider to get an idea of HS at other percentage values. I know its not exact but it should be within a few % of desired HS. That would be a good calibration test to see how far off it really is.

[Funflyer]

Downloading now, thanks for the hard work!

[NoJoy]

Great program, using it often. Is it possible to add Plettenberg motors to it? Those are used a lot over here in Europe.
Anyway, good prog, thanks!

Jan