Sig four * 40

[Redflier]

I would like to convert my four star 40 to electric. How does this sound?
AXI 2826/10
jeti 40 amp controller
3s2p 4200 mah Li poly
12x8 prop
What can I expect comparing to an OS .46 2 stroke glow.

[Tweet]

I think you would be disappointed with the performance compared to the OS 46. Here is a recommendation: 4S2P, AXI 4120/14, 15x10 or 14x8 prop, 60Amp controller (to be conservative).

I'm sure others will have suggestions as well. I think the Four * .40 will weigh about five pounds or so. Should be a nice airplane.

[big bird]

the risk is that you get too heavy with a big motor/battery combo like this, which kinda spoils the performance envelope to some degree.

there are lighter motors that will have the power you need ... try a Cyclon 60, and Plettenberg Orbit 25 or a Kontronik Kora 25 series ...

can you strip the airframe, lighten it up here and there and recover in a light weight film? You should be able to drop maybe 6 oz. this way .... it'll make a difference

big bird

[Redflier]

Sort of hard to strip much weight as this is an ARF. So many have such good luck with AXI motors and Hobby Lobby,but willing to listen to any ideas. I do like performance, power to spare, as in glow or gas. For example, my friend put AXI 28 series motor,10 cells in the "Twist". It did fly,but hardly any performance. I had a 70 4 stoke in mine. So now he is back to glow power too. I just don't want to start out underpowered. I have a lot to learn about electric, so just trying to understand this electric power before I jump in too far.

[Tweet]

You can go to town on weight reductions (stripping off covering, etc.), however I think the initial desire was to get an electric to fly with as much power as the OS 46. Fact is a lot of people buy ARFs so they don't have to do all this.

Redflier, I think you would not be happy with the 2826/x on this airplane, even with four cells. The 4120/14 does weigh an extra 4.8 ounces, but you have to compare that to the glow motor you are replacing, etc.

The setup I recommended would fly nicely, also Hobby Lobby tends to be conservative so whatever they recommend would probably work okay too.

I don't think "glow versus electric" on airframes any more. I buy the airframe I like and just happen to choose electric power. I don't strip airplanes down and recover for weight for electric any more than I would for glow.

[fourstarforty]

Here's a pic of my 4*40 scratch built,all balsa except for wing joiner and landing gear block.

Axi 2820 10, flying weight with maxamps 3s2p 4200 is 4lb, using gp 10 cell pack is around 4lb 7 oz flys great using either battery :)

[big bird]

well, being ARF does make it difficult - your ideal electric plane is as above - built light from a kit...

you may just have to bite the bullet on this ...it'll be that much heavier and expensive,... consider going with a Hyperion 40xx series motor, just as good as axi (maybe better) and a little cheaper.

big bird

[big bird]

www.rcgroups.com/forums/showthread.php?t=333410

this is how to do it...

watch his video in the above thread for the proof of the pudding

big bird