New Products Flash Sale
Thread Tools
Old Aug 12, 2015, 04:27 AM
delta245 is offline
Find More Posts by delta245
Registered User
delta245's Avatar
Joined Jul 2009
127 Posts
hello I have a skywalker 1680

with a motor NTM Prop Drive Series 35-36A 1400Kv
https://www.hobbyking.com/hobbyking/...arehouse_.html
apc propeller 9x6
lipos 8000 3s


I have a range of 25-30 km

I would change the engine for greater autonomy and a better quality

Have you any suggestions for me
delta245 is offline Find More Posts by delta245
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 12, 2015, 11:28 AM
henkvdw is offline
Find More Posts by henkvdw
KJ6BFN
henkvdw's Avatar
United States, CA, Fountain Valley
Joined Aug 2008
824 Posts
Quote:
Originally Posted by delta245 View Post
hello I have a skywalker 1680

with a motor NTM Prop Drive Series 35-36A 1400Kv
https://www.hobbyking.com/hobbyking/...arehouse_.html
apc propeller 9x6
lipos 8000 3s


I have a range of 25-30 km

I would change the engine for greater autonomy and a better quality

Have you any suggestions for me
Best efficiency on 3S I have seen reported, is by shadrack with his OS OMA-3820-1200.
Not sure about gaining "autonomy" by installing a different motor - maybe "authority"?
henkvdw is offline Find More Posts by henkvdw
Last edited by henkvdw; Aug 12, 2015 at 11:52 AM.
Reply With Quote
Old Aug 12, 2015, 02:51 PM
mike_o is offline
Find More Posts by mike_o
Registered User
mike_o's Avatar
Denmark, Nærum
Joined Jan 2012
2,103 Posts
Quote:
Originally Posted by delta245 View Post
hello I have a skywalker 1680...
I have a range of 25-30 km...I would change the engine for greater autonomy and a better quality...Have you any suggestions for me
By "range of 25-30km" do you mean max distance from home (if so, you'll have problems finding anything better) or round trip?

Also, is your goal max distance or max duration (time). And do you fly in windy condition ? Then you need a set up with more speed than for flying in calm conditions.

Basically, you should pick a motor that has max (or high) efficiency at cruise power. This often results in a set-up with very little power surplus, but thats a trade off.

Some of the NTM motors are not half bad with respect to efficiency, but the bearings are notoriously poor.

I have had succes with some of RC Timer's HP series motors, and I have just received a MultiStar Elite V2 and a SunnySky, which should both work well. They are all better quality than the NTMs, imo.

My SW1680 also use a 9x6 APC prop, but currently with a 1020KV 3630MM RCT HP motor. I can easily go 13km out (and come back) on a 5200mAh 3S battery.

You probably should aim for a little lower KV than 1400, maybe around 1100. And the motor should not be too big; 3536 or 3530mm.

Try also working on the aerodynamics. Lowering drag has a magical effect on the speed/range/duration. Keep in mind then the trailing edges are more important than the frontal area. The trailing edges of the wings/ailerons should be as thin as possible
mike_o is offline Find More Posts by mike_o
Reply With Quote
Old Aug 13, 2015, 02:29 AM
delta245 is offline
Find More Posts by delta245
Registered User
delta245's Avatar
Joined Jul 2009
127 Posts
with this configuration

total flight 25-30km

for the moment i go 10km out (and come back) and i know that i over more 5-10km (if i have a problem )

i have see OS OMA-3820-1200
http://www.rcgroups.com/forums/showp...&postcount=193

I appeal to your experience because I want to be able to cover more distance by changing the engine or the propeller

my propeller is apc 9x6 sf(slow fly) ( more thrust than apc 9x6 e )

I know it is a compromise by adjusting thrust, speed or autonomy

how is it possible to thin the trailing edges of the wings / fins ???
delta245 is offline Find More Posts by delta245
Last edited by delta245; Aug 13, 2015 at 02:55 AM.
Reply With Quote
Old Aug 13, 2015, 11:19 AM
henkvdw is offline
Find More Posts by henkvdw
KJ6BFN
henkvdw's Avatar
United States, CA, Fountain Valley
Joined Aug 2008
824 Posts
Quote:
Originally Posted by delta245 View Post
my propeller is apc 9x6 sf(slow fly) ( more thrust than apc 9x6 e )
9x6SF will also draw more current and while coasting have more drag than 9x6E.
It is the first component I would change to see if I can get better efficiency.
More thrust is good and nice to have but with 9x6E you will still have more than enough thrust and probably a gain in efficiency.
henkvdw is offline Find More Posts by henkvdw
Reply With Quote
Old Aug 13, 2015, 02:37 PM
bhoov128 is offline
Find More Posts by bhoov128
John 20:1-18
bhoov128's Avatar
United States, FL, Davenport
Joined May 2012
11,951 Posts
Quote:
Originally Posted by henkvdw View Post
9x6SF will also draw more current and while coasting have more drag than 9x6E.
It is the first component I would change to see if I can get better efficiency.
More thrust is good and nice to have but with 9x6E you will still have more than enough thrust and probably a gain in efficiency.
Another reason to change to 9x6E: Safety. SF propellers are slow fly for a reason. APC's recommended RPM limit for that prop is well below what you're giving it.

From APC's recommended RPM range:

SF propellers: 65,000 / prop diam = 65,000 / 9 = 7,222.22 RPM
3S full charge 12.6V * 1400KV * ballpark 80% efficiency = 14112 RPM.... 2x recommended.

E props are 145,000/prop diam which gives you 16,111 max RPM to play with, which is where you want to be.

You don't want to be 10km out and throw a prop blade because you're spinning it too fast, even if it is actually unlikely.
bhoov128 is offline Find More Posts by bhoov128
RCG Plus Member
Latest blog entry: Snice Slick
Reply With Quote
Old Aug 13, 2015, 04:22 PM
delta245 is offline
Find More Posts by delta245
Registered User
delta245's Avatar
Joined Jul 2009
127 Posts
thanks guys !

i have one apc 9x6E

I just tested yesterday before flying but I have not dared to fly with

now i know that's better efficiency
delta245 is offline Find More Posts by delta245
Last edited by delta245; Aug 13, 2015 at 04:27 PM.
Reply With Quote
Old Aug 13, 2015, 04:42 PM
mike_o is offline
Find More Posts by mike_o
Registered User
mike_o's Avatar
Denmark, Nærum
Joined Jan 2012
2,103 Posts
Quote:
Originally Posted by delta245 View Post
....how is it possible to thin the trailing edges of the wings / fins ???
Several options:

Run two fingernails down the edge while pinching/pressing it. Do it 3-4 times, and you'll see that the foam has compressed to about 50-60% of original thickness. Only do the edges, as this will weaken/collapse the foam structure.

Use a sharp hobby knife using a ruler to guide it along.

Or cut away the outer 10mm and replace with a triangular balsa piece. Hot glues or CA-glues nicely in place and can be secured with tape. Check out my 2500mm Diamond conversion (link) to see an example (my first attempt).
mike_o is offline Find More Posts by mike_o
Reply With Quote
Old Aug 13, 2015, 05:40 PM
delta245 is offline
Find More Posts by delta245
Registered User
delta245's Avatar
Joined Jul 2009
127 Posts
thanks mike , good solution !

if i understand , you have add triangular balsa piece and not cut ?

i can make that ( more surface ! )

i have read your post
http://www.rcgroups.com/forums/showthread.php?t=2407097

but don't know your final choice
delta245 is offline Find More Posts by delta245
Reply With Quote
Old Aug 14, 2015, 02:51 AM
mike_o is offline
Find More Posts by mike_o
Registered User
mike_o's Avatar
Denmark, Nærum
Joined Jan 2012
2,103 Posts
Quote:
Originally Posted by delta245 View Post
thanks mike , good solution !

if i understand , you have add triangular balsa piece and not cut ?

i can make that ( more surface ! )

i have read your post
http://www.rcgroups.com/forums/showthread.php?t=2407097

but don't know your final choice
For my SkyWalker 168, I used a combination of cutting and pinching/compressing the edges.

The 2500mm Diamond is different from the SkyWalkers in that way that it's wing aspect ratio is much higher (Being a motor glider, the Diamond has much longer / narrower wings and could do with a bit lower aspect ratio for powered flying), and I wouldn't change the aspect ratio of the SW.
mike_o is offline Find More Posts by mike_o
Last edited by mike_o; Aug 14, 2015 at 03:05 AM.
Reply With Quote
Old Aug 24, 2015, 09:45 PM
carboncopy101 is offline
Find More Posts by carboncopy101
Registered User
Joined Feb 2015
26 Posts
Hi! How is the glide ratio of the skywalker? Any ideas? Also in general can this plane function just as well as a glider in terms of cruising?
carboncopy101 is offline Find More Posts by carboncopy101
Reply With Quote
Old Aug 26, 2015, 03:37 AM
mike_o is offline
Find More Posts by mike_o
Registered User
mike_o's Avatar
Denmark, Nærum
Joined Jan 2012
2,103 Posts
"v6" in back HK stock. But new wing

If you notice the famous version 6 being announced back in stock in HobbyKing, pls notice that it is NOT the original v6 wing, but the newer 1720mm wing. It has a longer wing cord and inboard (inside the dihedral) alierons, which has less authority than those of the original v6.

Having both the original v6 and the new 1720mm SW, I feel that the v6 wing profile has better efficiency (higher aspect ration), while the newer wing has more area and more lift.

Can anybody confirm what happened to the original v6 wings, btw? Did the mould form really disappear into a far away galaxy?


Quote:
Originally Posted by carboncopy101 View Post
Hi! How is the glide ratio of the skywalker? Any ideas? Also in general can this plane function just as well as a glider in terms of cruising?
None of my SWs glide nearly as good as my dedicated motor gliders (e.g. 1800mm folding prop EasyGlider) The SWs are, however, efficient planes for powered flight. Especially for long duration or low wind condition. For max distance, the Talon seems to be the best plane available rigth now.
mike_o is offline Find More Posts by mike_o
Last edited by mike_o; Aug 26, 2015 at 03:43 AM.
Reply With Quote
Old Aug 26, 2015, 03:43 AM
carboncopy101 is offline
Find More Posts by carboncopy101
Registered User
Joined Feb 2015
26 Posts
I heard the mold for v6 was broken
carboncopy101 is offline Find More Posts by carboncopy101
Reply With Quote
Old Aug 26, 2015, 10:27 PM
carboncopy101 is offline
Find More Posts by carboncopy101
Registered User
Joined Feb 2015
26 Posts
Quote:
Originally Posted by mike_o View Post
If you notice the famous version 6 being announced back in stock in HobbyKing, pls notice that it is NOT the original v6 wing, but the newer 1720mm wing. It has a longer wing cord and inboard (inside the dihedral) alierons, which has less authority than those of the original v6.

Having both the original v6 and the new 1720mm SW, I feel that the v6 wing profile has better efficiency (higher aspect ration), while the newer wing has more area and more lift.

Can anybody confirm what happened to the original v6 wings, btw? Did the mould form really disappear into a far away galaxy?


None of my SWs glide nearly as good as my dedicated motor gliders (e.g. 1800mm folding prop EasyGlider) The SWs are, however, efficient planes for powered flight. Especially for long duration or low wind condition. For max distance, the Talon seems to be the best plane available rigth now.
I see. Ordered a mini figured I could try the smaller one first haha
carboncopy101 is offline Find More Posts by carboncopy101
Reply With Quote


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Question Best plane for FPV while on vacation? patricklupo FPV Aircraft 24 Nov 23, 2014 03:56 PM
Cool FPV plane rescue with an FPV truck :-) AnthonyRC FPV Aircraft 17 Feb 24, 2008 10:45 PM
For Sale Skywalker plane and a bunch of extras moody07747 Aircraft - Electric - Airplanes (FS/W) 8 Sep 19, 2006 09:34 PM
Discussion Aviator Skywalker RC plane given to me moody07747 Electric Plane Talk 46 Sep 12, 2006 11:45 AM