squeaky penguin

Hi all,

I got an Axi 4120/18 in a trade that is mounted on a .46 size Cap 232 that is suppose to weigh 5.5-6lbs. First off will this motor be a good fit for the plane? It appears to be a .60 size replacement, but I do live at 7,000'asl and wouldn't mind the extra power.

That in mind what battery ESC combo should I go with. I was thinking about a 5s would give me the right power, or do I need 6s? I guess that would then equate to a 4000-5000mah battery and about an 80amp ESC?

I've done a lot with electrics, but never anything this big. I just don't know where to start,

Thanks,

Brett

Dr Kiwi

http://www.modelmotors.cz/index.php?...e=18&line=GOLD


It seems to be rated very sensibly for around 3W/g = 960W max.. which gives you about 150W/lb....so on 6s that's about 40A....5s will let you use a slightly larger prop which might be advantageous given your altitude.... the Axi site indicates around 12x8 on 6s... 13" on 5s.

squeaky penguin

So the idea behind that is on 5s, you would have less rpm, allowing you to use a larger prop? Giving you similar current draw? I went ahead and orderd an Ice 75. So I'm good there, just trying to figure out the battery. Is 5000mah overkill for a 46 size electric? Looks like it will physically fit, of course a small battery will be less weight and could provide better performace.

Thanks

Dr Kiwi

Assuming equal C-rating, a larger mAh battery will cope with current draw better (less voltage drop under load)... and will give you better motor performance and longer flight time... conversely a lighter battery may give you better flight performance!

ray foley

hi there from Toledo

With my axi 412018 I typically use 4000 mah lipos, a 2s and a 3s connected in series and prop for about 750 watts. I works great. At 7000 asl i can't recommend a prop or pitch but a watt meter will help you get it right.

ciao -rjf

squeaky penguin

Already picked up some 5000mah 5s 20c batteries. I don't have the patience for charging two batteries for one flight. I've got a bunch of props to try and will run it though the watt meter before I madien it.

squeaky penguin

Had it out at the field yesterday, and ran it though the wattmeter. The biggest prop I had out there was a 15x6, and it only pulled 32 amps for about 600 watts. 30 amps with a 14x7. On the postive note it flew well even with that setup. Hovering at 3/4 throttle.

So, time to order some more props. I might be able to fit a 16" with some bigger wheels. So maybe a 15x12, or 16x10, or 16x8. I think 40-45 amps would be best.