Thread: Mini-HowTo Beginners Guide to Motor and Prop Selection View Single Post
 May 03, 2010, 04:35 PM Suspended Account Joined Jul 2006 22,991 Posts Dialing in a perfect 1.00 Gear Ratio Now we'll use our example above to set that gear ratio exactly to 1.00 from it's present value of .99 even though for all practical purposes, we don't really need to, because .99 is almost exactly a 1.00 gear ratio. We will always use the following steps to accomplish this task, so follow along with me as I do it for you. 1) Change the "Desired Top Speed" box on the left hand side to 39.9, which is what the suggested APC 10x7SF prop is showing as a top speed in the output table on the right. 2) Now, in order to raise the .99 to our desired 1.00, we must lower the "Desired current..." box on the left hand side. So what we'll do is lower the Desired Current a couple of tenths to 12.4 Amps. (We can lower it by a single tenth if we really want to, but from experience, I can say that a couple of tenths is a good starting point). 3) Hit the Calculate button and see our results. When we hit the Calculate button we still see our .99 in the gear ratio box. No big deal! This just shows we are really close to getting it now. So we will repeat the process over again. 1) Change the "Desired Top Speed" box on the left hand side to 39.6, which is what the suggested APC 10x7SF prop is now showing as a top speed in the output table on the right. 2) Again, since we want to raise the .99 to 1.00, we lower the "Desired current..." box a couple more tenths of an AMP, to 12.4 this time. 3) Hit the Calculate button and BINGO, we have now dialed it in perfectly. Last edited by NoFlyZone; May 03, 2010 at 05:27 PM.