I am not a big fan of any programs. Just as you point out there are too many variables. I use the actual equipment ant a watt meter.
Watt Meter would be great if you had a box full of props, batteries, and controllers laying around to find the best match, but I need to get in the Ball Park First.
Have not found any charts with Electric Motor - Prop selectors as of yet. Easy to find for gas engines.
Got a couple of planes I want to upgrade the motor, ESC, and prop. Since I am a beginner need a crutch to gain experience. My biggest advantage is I am an EE with a fair amount of Motor and Controller experience and a lot of battery experience although not LiPo but the principles are the same, just much smaller scale.
Calculators like drive calculator are great but only if they have the information you want or you can enter the information you want. I use MotoCalc and it can help with the planning stage of a power system.
Looking at the manual for drive calculator it shows that you can edit an item. This is what would allow you to enter a motor that is not there, if the vendor supplies the needed info and that info is correct.
You can also get in the ballpark with smaller planes by following their limitations. If it has so much room for battery or can spin a 9 in prop before it hits the ground your system can start at that spot.
Watts per pound is another way to get close. If you know what you have in the plane now and know what you want the process becomes more simple.
I use MotoCalc to find the prop and cell counts for a motor I have. Works well for that. But I double check everything with a meter or better a data collecting ESC.
With the ESC I found that a plane set up for 1500 watts flies at less than 16 amps for most of the flight (cause I am chicken on the sticks). This type of data will let you get the most out of any motor by fine tuning the prop for the batteries that fit in the plane.
I struggle with the overwhelming combinations that are possible when just starting and these are the pathways that have worked for me.
Sorry I can't help you with editing an item in drive calculator but the instructions seem easy to follow.
Flying is like ... ah well ... I can not think of anything it is like...
go to headsup rc they list thrust with different prop & battery combos. for each engine this should get you in the ballpark
Thanks for the info. I am familiar with Heads Up RC and this is kind of the issue I have. On the program are a lot of motors, but not any for suppliers like Heads Up, or even popular ones like E-Flite.
What I am really try to say is how can I build my own motor model on say like a 15 to 25 size motor?