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Old Jan 08, 2013, 12:01 AM
Registered User
Marshall Islands, Enewetak Atoll
Joined Sep 2011
1,048 Posts
Skyfun 80mm ducted fan experiment:

2nd maiden flight yesterday if there is such a thing, 1st flight crashed within 5 seconds because the vibrations scared the FY-30a.

Yesterdays flights went fantastic. Pretty stiff wind (15 mph+) but the Skyfun always loves that. 1st flight flew with a 2800 mah 4 cell (30c) and as I've been hearing the EDF's lack a lot of static thrust when stationary so when it was thrown (a friend threw it for me) it seemed like it might stall but then the EDF started to get "on step" or "on the pipe" and then it gained speed quickly. Seemed to be going 70 -80 mph easily.
It was heavy (2lbs 8 oz) but flew great. Landings were even better. I usually turn in to land at a pretty high altitude and dive steeply with throttle off, flare, and then try to stay in ground effect and float along within a foot or two of the grass until the speed scrubs off. This worked perfectly with a heavy Skyfun and eventually it slowed enough to perform a final flare and then it plopped down and slid maybe 5 feet. A little grass in the EDF but it blew off with a couple blips of the throttle.
The 4000 mah 6 cell seemed too heavy (1.5 lbs by itself) so I'll wait and see what that feels like.

All in all I have to say that the Skyfun + EDF is a great combination. Side benefit: no worries about finger strikes or hitting the prop when landing.

I'll try to record the next flight and post later.
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Last edited by ecworks; Jan 08, 2013 at 10:55 AM.
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Old Jan 19, 2013, 02:39 AM
Flying Zayin
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China, Guangdong, Guangzhou
Joined May 2012
914 Posts
Skyfun + Storm OSD problem (cross-posted from other thread)

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Old Feb 08, 2013, 05:12 AM
Registered User
Canberra, Australia
Joined Jan 2008
60 Posts
Removable vertical stabalizers (fins)

Hi All,

As anyone build the skyfun with removable fins? I'd like to make mine as portable as possible for taking on holidays.

I havent started building yet, the kit just arrived today. It appears the fins would be a fairly snug fit once the wing is glued. Do you think some velcro dots embedded in the wing and fin base would hold them in?

I'm planning on using the skyfun for cruizing and FPV, not as a speed demon.

I note that my windrider elebee wing has coroplast fins held on with velcro and while they probably flop around a bit, they have never come off or caused me any grief.

Interested in your thoughs, thanks,
Dave

Edit: magnets would probably be even better than velcro
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Last edited by davico; Feb 08, 2013 at 07:52 PM. Reason: magnets
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Old Feb 09, 2013, 10:35 AM
Flying FPV from the lab.
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Canada, AB, Lethbridge
Joined Jun 2008
2,116 Posts
You could hot glue them in, and separate them each time you need to break the plane down for travel. Rigid enough to survive aerobatics,and you can remove the glue without too much effort. Buy a lipo powered glue gun from hobby king for the field. Good for quick repairs too :-)
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Old Feb 09, 2013, 04:40 PM
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Australia, New South Wales, Sydney
Joined Jan 2011
115 Posts
Quote:
Originally Posted by davico View Post
Do you think some velcro dots embedded in the wing and fin base would hold them in?
No, I think that would be decidedly inadequate. It would be best to pin them in somehow with a removeable locking system. An example of this would be to epoxy hollow carbon tube (3mm) inserts into the stablizers that penetrate the fuselage when installed, then use self taping screws and washer to secure the tubes at the bottom by screwing into them. Epoxy the ends of the tube to avoid splitting but give some for the screws to bite into.

The skyfun, especially when matched to a bigger motor will develop strong forces on the parts - losing engine mounts and canopies used to be common place (and catastrophic for flight) and although the engine mounts are much better stock now you should also take steps to improve the very poor canopy mounts with a combination of strong magnets and/or nosepin with rubber bands for the front of the plane.
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Old Feb 09, 2013, 06:57 PM
Note to self, put on pants.
Jayman72's Avatar
Australia, VIC, Frankston
Joined Mar 2012
89 Posts
Magnets may be enough. I hold on my canopy with old hard drive magnets. VERY strong.
But if you added a hinge on one side of the fin and fuse with strong magnets on both items, you could fold them flat for transport and stand them upright for flight. And if they dislodged in flight you wouldn't loose them, a quick roll would lock it back in.
Jamie
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Old Feb 16, 2013, 01:55 AM
Gravity sucks.
Australia, QLD, Toowoomba
Joined Mar 2011
563 Posts
Quote:
Originally Posted by davico View Post
Hi All,

As anyone build the skyfun with removable fins? I'd like to make mine as portable as possible for taking on holidays.

I havent started building yet, the kit just arrived today. It appears the fins would be a fairly snug fit once the wing is glued. Do you think some velcro dots embedded in the wing and fin base would hold them in?

I'm planning on using the skyfun for cruizing and FPV, not as a speed demon.

I note that my windrider elebee wing has coroplast fins held on with velcro and while they probably flop around a bit, they have never come off or caused me any grief.

Interested in your thoughs, thanks,
Dave

Edit: magnets would probably be even better than velcro
The best solution i've seen that would apply here is a couple small (strong) magnets fore and aft coupled with some short dowels or (CF or GF) rods about 35mm long, leaves 15mm in fuse (in tubes) and 15 mm in each rudder.

Were I to get another kit - that's what i would do with them.
if it's a slightly tight fit, there would be little chance of loosing them in flight.
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Old Mar 04, 2013, 04:20 AM
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Canberra, Australia
Joined Jan 2008
60 Posts
Thanks for the suggestions, I went with strong 6mm x 2mm rare earth magnets as shown in the picture.

Other build details are:

- Wing joined with foam-safe CA on one surface and a very fine mist of kicker on the other (too much CA+kicker will eat the foam).
- Carbon ribon spar across the length of the wing (I think it was only 3mm carbon).
- re-hinged the elevons with hinge tape as the stock ones were aweful
- covered the underside centre section with laminating film
- Some carving here and there to fit the HK 40A esc (its huge for some unknown reason), and for mounting the battery towards the rear once the rest of the gear goes in.
- NTM 2836 2700kv motor mounted on a windrider ele-bee motor mount. I found the motor would rub on the stock mount. The windrider mount works very well.
- Servos are hxt900's as one of the metal-gear ones I bought for it failed just *after* I finished installing the guards. I hope they hold up ok..
- 5.5x4.5" APC prop since its all I had, will try a larger one at some stage.
- 2200mah 3S battery
- 40% rates on elevator with 30% expo. 50% rates on aileron I think.

Flying weight as pictured with 2200 3S and no FPV gear is 715g.

I maidened it yesterday and put 4 packs through it. Flew very well, plenty of power. I did some short burst of full trottle and even a few rolls at high-rates (balistic!) and the fins didn't budge. So I think for my intened purpose (FPV cruising) it should hold up ok. I may add carbon rods for additional security as suggested though. 6min flights on a mix of throttle consumed approx 1200mah from the battery.

Next step is to add an APM2.5, and finally the FPV gear!

Dave
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Last edited by davico; Mar 04, 2013 at 04:26 AM. Reason: add some more build details.
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Old Apr 01, 2013, 02:03 PM
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Joined Apr 2012
937 Posts
Looks great! What is the AUW of your skyfuns out there?
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Old Apr 17, 2013, 08:08 AM
Registered User
Canberra, Australia
Joined Jan 2008
60 Posts
As shown here with APM2.5 autopilot, telemetry radio, pan/tilt camera, video tx etc and a 2200 3S, mine now weighs 860g. It flies superbly like this.
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Old Apr 17, 2013, 05:58 PM
Multi Rotor Maniac
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Australia, VIC, Melbourne
Joined Oct 2007
2,843 Posts
Nice work Davico. Do you plan on flying it using APM waypoints? That would be pretty awesome to map out a route with google then kick back and take it all in using the pan n tilt
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Old Apr 18, 2013, 07:24 AM
Registered User
Canberra, Australia
Joined Jan 2008
60 Posts
The APM (actually an rctimer ArduFlyer) is working very well with minimal tuning. I have flown a simple 4-waypoint box around by flying field which worked great.

I actually don't have the tilt servo connected atm, I just have pan on the rudder stick. My dominators have head-tracking, so I should be able to do full pan/tilt

I've only had a brief FPV stint between LOITER commands to get a feel for it. No takeoffs or landings yet.

My intension for this plane was a portable FPV craft for holidays/camping etc. Though I'm tempted by the TBS Caipirinha now as it better fits my original concept (slower, better range, more durable, less akward shape, carries a gopro etc).

This thing flies like its on rails, love it.

Dave
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Old May 18, 2013, 03:17 AM
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Joined Apr 2012
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Nice! im using 3700mah in mine and weight is 980g lol :P
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Old May 19, 2013, 06:53 PM
what goes up, must come down..
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Joined May 2010
2,931 Posts
Quote:
Originally Posted by timtimtim View Post
Nice! im using 3700mah in mine and weight is 980g lol :P
I am curious, how difficult is she to hand launch at almost 1kg?
Also at that weight, has the stall speed significantly increased?

Yesterday i maidened my skyfun v1, rock stock with 2100mah 3S, what a fun lil' bird! Slow as a wet wig as expected, but still snap-ish rolled ok & managed a loop with a big run up lol
You guys were right, can be flown very surprisingly slow & flies straight as an arrow. I am very happy with it and can see the potential as a great all rounder ie regular flying speed doing circuits with others, or punch the throttle for crazy speeds :-)

My thoughts are, now i have seen it:

Definate cf ribbon spar underneath, conveniently flat enough to make it easy.
I was thinking perhaps making the underside of the motor mount a little more aerodynamic ie i stead of being square maybe shave the foam to make it more rounded to help the prop?
The foam canopy really does seem to be almost a structural piece for the fuse, thinking once i have all my bits in place in the fuse, i might permanently glue the foam canopy in place, this can only be a good thing regarding stiffening the fuselage longitudinally. The only challenge then is how to make the plastic cockpit clear open for battery access, keeping aerodynamic smooth lines for speed, but not add weight...
Strengthen the motor mount
Top mount the servo arms, protect on belly landings and do away with the servo covers.
Balsa elevons with dubro hinges.

A fun plane, soon to become even more fun :-)
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Old May 20, 2013, 02:35 AM
Registered User
Joined Apr 2012
937 Posts
not my vid,I launch it like this with 3 clicks of elevon trim works fine!
How to launch a skyfun flying wing (0 min 9 sec)
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