ORIGINAL: krashkart
I downloaded the trail edition of Motor Calc just to see how it worked and with the 450 motor and my plane and a 3s battery it came up with a 10x8 as the ideal prop.
I see however that using that program could help me with my needs and save me money in the long run.
I just might have to pay the $39 and go ahead and get the full version of it.
It just might be cheaper than running 20 miles to the LHS and guessing on props and trying them to find out that I am pulling too many amps.
The more tools you have and know how to use the better.
Use the present motor calc and run an assortment of props through it. Then try them to see if your readings match up to the predictions.
The last time I was in your situation, that's what I did. It was eye opening when I got the real props on the real airplane and ran them. About half of them did not produce as predicted. Some didn't get the power out. Some didn't turn the rpm. One even gave more rpm than predicted.
Good thing was how much time I saved not flying something that wasn't up to the mark.
The whole process provided a bunch of experience. Best thing about it was seeing what worked and what didn't. Next time won't take half the number of props or time. It was really true that theory often doesn't provide very good answers when you actually "ask the question".