Sig Something Extra

[gouda]

We'll try this on this forum:



I just aquired one of these and plan on doing it as EP. I have a Axi 4120/14 on hand. is this overkill? Or about right? I'm interested in aerobatics, but not 3D. I don't think this plane is meant for that anyway. Of course, the other option would to get a different motor, any suggestions? Hacker, etc.

[CUBANO8]

Give us more Info about the plane; weight,size,tail-dragger,etc.
I'm using that 4120 on an 8lb SA Corsair and it pulls it quite nicely.
I usually go with 100watts per pound formula, on my conversions.
example:

8lbs of plane needs 800watts of power, so with the 4120 at 40amps and 20volts should get you to 800watts.

Don't know much on Hacker motor, haven't used one on any of my setups.

[just_lkn]

I was considering the same thing but am wondering if wing loading would be to high.. I was considering a 5s 6000ma battery and the same motor as above axi 4120

Specs for the the sig

SPECIFICATIONS
Recommended Engines:
.40-.46 cu.in. 2-Stroke
.56-.65 cu.in. 4-Stroke
Wingspan: 51.5 in.
Wing Area: 614 sq.in.
Weight: 4.25 - 4.75 lbs.
Wing Loading: 15.9- 17.8 oz./sq.ft.
Length: 48.25 in.
Radio Required: 4-Ch w/5 Servos

[CUBANO8]

With those specs you really don't need a 4120. I think you would be fine with a AXI 2826/10. If you want to go with a 5s, consider getting one 2s2p 4200 and one 3s2p 4200, and putting them in series.
They will be smaller packs, and you could moved them forward to balance your plane better than larger 5s 6000ma pack. I was looking for that particular plane, and I found it in tower hobbies. It looks very nice.

Good luck, and I hope you start a build thread on it. I would like to follow.

Sam

[gouda]

Hi Sam;

My motor (2826) just showed up today. So I'll try and get started over the weekend. Your battery idea sounds good as well. And maybe not so spendy.

[thunder1]

I'm running the AXI 2826/10 with a 4s2p 4000 mAH pack (4 - 2s 10C RC-Dymond packs) and an APC 12x6E prop. It pulls my 5.5 lb Super Chipmunk along nicely. Not unlimited vertical but nice large loops and all the standard aerobatics you can throw at it. I usually fly for 12 minutes and put about 3300mAH back into the pack.

[big bird]

if you're building from kit i'd suggest going the Daking route. - do a search for his SSE flying at 51oz. Fully aerobatic/3D whatever you like

uses a cheap and light weight geared system and the super low weight means outstanding flight performance

big bird