Yesterday I tried flying my 168cm Skywalker with a 5000mah 4s for the engine and a 2200mah 3s for the vtx.
Total weight was 2kg and flying it was a challenge. Gliding was not really fun, most of the time I was under motor power and overall the plane behaved more nervous to any aeleron inputs. When I banked slightly, the plane would drop off a lot faster.
All in all to be expected but I am wondering how people even fly with 2 x 5000mah and also, how can you cram 2 of those beasts into that plane? Side by side I could barely fit my 4s and 3s and on top of that, I had to move them so far back for the COG, that I had to replace all the electronics.
So what do you guys fly? Is it worth looking into getting the extended wings for the Skywalker if I want to take off at +2kg?
How was your CG balanced with that weight?
CG tends to be much more important than total weight. Bad CG means it will fly like shit. Your description of bad glide and lots of slip in the turns sounds to me like your CG is all off.
I fly with 5000mah 3S and a 1300 3S (for vex and cam etc) plus a GoPro but can't give you a weight just now as I'm on hol :D
I know it will be about the same weight as yours or more and it flies and glides ok, so much so that I've fitted spoilers to the top of the wings to. Get it down from height when I get bored !
From what you say about the ailerons being over sensitive and dropping in turns it sounds like it is flying tail heavy so the C of G a bit too far back at the moment.
Have a go moving the lipo's forward a bit to move the C of G 5mm forward, give it a try then maybe move another 5mm.
I'm pretty sure you will see an improvement, when I get home next week I can tell you my C of G position (how many mm is yours from the leading edge, what version SW is it)
PK
I have flown all my Walkers on a 5000 4S and 2200 3S on board. There is no problem as long as the CG is right. CG should be 20 - 30 mm behind servo wire slot.
Thats what I thinks wrong, I could glide mine around for ages with no motor power
Control throws only want to be 10 - 20 mm max
I do have the COG 30mm behind the servo line, maybe i should try closer to 20mm.
My gopro is also on the nose, so that weight needs balancing which is why i end up pushing the lipos so far back.
Is that the stock BEVRC motor ? If so its not very good with a decent amount of weight on board
Yes, thats the one. Mind you, I never fly more than 50% throttle with only my 4s lipo onboard. When I loaded it with both lipos, I was about 3/4 throttle for steady flight. So you suggest a better pusher? Anything perticular you would recommend, maybe from the big fish?
My new one has an Overlander 3542 1450Kv 480 watt on a 9x6
http://www.overlander.co.uk/motors/outrunner-motors/tornado-thumper-v2-3536-1450kv.html (http://www.overlander.co.uk/motors/outrunner-motors/tornado-thumper-v2-3536-1450kv.html)
I asked on RCG for a few Motor / Prop combo`s and from the replies came to this option as better power but decent cruise current draw
Quote from: markvanhaze on May 16, 2012, 12:16:35 PM
I do have the COG 30mm behind the servo line, maybe i should try closer to 20mm.
My gopro is also on the nose, so that weight needs balancing which is why i end up pushing the lipos so far back.
30mm behind the servo line is tail heavy I am flying 15mm behind the servo line on a V5.1 Skywalker, and it flys great with a 4s 5000mah and a 3s 1300mah onboard. I have scales but no method of balancing a skywalker on them, but seeing how the batteries are the main variable in weight you can see we are not miles apart. I dont have the stock bevrc motor instead I have a 3542 1000kv motor http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=18163 (http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=18163) Not the cheapest but plenty of grunt
2200mah for the vtx seems like overkill to me and will mostly just be dead weight, can you move to a 1 power source system? or go to a smaller lipo for the vtx
Quote from: Coyote on May 16, 2012, 12:20:57 PM
Is that the stock BEVRC motor ? If so its not very good with a decent amount of weight on board
I use the BEVRC motor in teh skywalker combo pack and I can cruise at 30-32% throttle on a 4S 5000mah battery whil carrying a 3s2200mah and a 3s 1000mah battery along with full fpv rig and horyzonhd cam, and sometimes a canon sx260 camera for mapping. though I cruise closer to 40% throttle with the canon camera. i can fly at a pretty extreme incline anywhere near full throttle. I am using the 1880 wings...could they make all that difference?
Or did BEVRC change the motor in the kit?
Quote from: geobduffy on January 15, 2013, 10:11:24 PM
Quote from: Coyote on May 16, 2012, 12:20:57 PM
Is that the stock BEVRC motor ? If so its not very good with a decent amount of weight on board
I use the BEVRC motor in teh skywalker combo pack and I can cruise at 30-32% throttle on a 4S 5000mah battery whil carrying a 3s2200mah and a 3s 1000mah battery along with full fpv rig and horyzonhd cam, and sometimes a canon sx260 camera for mapping. though I cruise closer to 40% throttle with the canon camera. i can fly at a pretty extreme incline anywhere near full throttle. I am using the 1880 wings...could they make all that difference?
Or did BEVRC change the motor in the kit?
I'm wondering, where is your CG on 1880 wing?
Mine is around 15mm behind the servo slot and not sure weather i should push it more backward.
I've noticed that plane has issues with adverse yaw effect so had to replace servo horns and reposition servo arms to get some hardware differential in.
So my Skywalker 1900... I fly with 2x4000 4S packs. Mine is definitely very heavy as I have added lots of reinforcement, probably got a few ounces of glue... Also LED's everywhere, wings are painted.
I don't have a seperate flight battery, why the hassle of fitting two packs?. get a lc filter and a regulator, about £5 worth of components .
Hey Mark, I really struggled with power on the stock motor on my Skywalker (1900) and eventually had to replace it as it seized up. I put on an O.S. OMA-3820-1200 motor which is an absolute beast and has transformed the plane. Weight isn't really an issue now, with a 5000mah 4S and 3s 2500mah I can do vertical climbs for a good 7seconds without stalling! Cruising I can have the throttle at bare minimum, well worth an upgrade if you're struggling for power.
bevrc motor is really nice for Skywalker on 9x6 apc prop and 4S SW can go anywhere.
I got setup like this and use 7200mAh lipo onboard ,DOSD,FY30A,Gopro in case and original mounts,UHF ,wings are laminated and SW flying like on rails ,can do slow and really stable.
also it's not amps hungry.
Quote from: pardonator on May 28, 2013, 01:07:13 PM
I put on an O.S. OMA-3820-1200 motor which is an absolute beast and has transformed the plane.
I second that, exact motor that I have. It's probably overkill but I've never flown with anything else and I think it's just the right amount of power, great for initial take off and climb out.