HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jul 05, 2001, 03:28 PM
Registered User
San Diego
Joined May 2001
24 Posts
Giant Kolibri questions.

Well I got the plans for the Kolibri and after going over it for a while i decided that the plane is just to small, so i was going to scale it up 2x 2.5x times and runn it with a 400 size motor prop combo that I have right now. Ahs anybody done this, the main reason that i am doing this is I want to fly outside in no wind but still be able to do ultra slow flight. I will be using just a basic 400 with a 500a batt and a zagi contorler that i have. 555 reciever I think that I can get it under 13 oz. Still have to order the mirco servos any suggestions. Any problems that you see with this. I was hoping to us a carbon rod instead of a brass one for the fusaluge and will probably go witha T tail to keep things simple.
St0rmBringer is offline Find More Posts by St0rmBringer
Reply With Quote
Sign up now
to remove ads between posts
Old Jul 06, 2001, 09:38 PM
Registered User
Ben Lanterman's Avatar
St. Charles, MO USA
Joined Jan 2001
668 Posts
I have experimented with something similar. I started out with a Stubenflege with a Feather rec, HS 50 servos, DC1717 motor which is still flying and I still really enjoy it.

I managed to lose the battery pack in multiple loops (slipped out of the retaining clips, my fault) and when I moved the stick - nothing (forgot that it was a ESC device). I tried to control it until the airplane hit the ground. It was going straight down. Both V tails were sheared off from the impact. I repalced the V tail with a conventional (T) tail made of 1/32 balsa because I had no carbon rod.

I think the conventional tailed airplane handles a little better than the V tail and is not much heavier. It is still a great slow flying aircraft. I do pylon runs around the mailbox and a street sign. A lot of fun.

Recently I found a package of bamboo rods that were 12 inches long and probably 3/32 in diameter. The type used in cooking. I made a loop out of them that gives a wing that looks like the Stubenflege/Kolibri and is floppy as a wet noodle. I called the plane Warpy due to the floppy wing. I followed the layout of the Stubenflege but used a lot of guying strings (dental floss) that give the wing shape and stiffness (looks good too). The wing is 40 inches span by 10 inches chord. I put in ribs made from bent bamboo that give about 1/2 inch camber and the whole thing is guyed/braced and becomes really strong and structurally stable. The key to using a big light wing is using the guy strings. Look at a really old preWWI airplane and copy what they have done. It works very good.

The tail is a scaled up conventional tail made out of 1/16 sheet balsa. Just use what look nice. Just for kicks I guyed the tail and fuselage too. The moments, etc are scaled up. I used a stiff balsa stick fuselage 1/4 by 2/8 inch and landing gear is thin wire with old servo wheel output things for wheels. Is is springy but works well. Landings are a no bounch affair. I use a geared Speed 280 motor, 10x4 slowfly prop, the receiver is a 555, Jeti 05 ESC with two HS55 sized servos and batteries have been between 8 of 120 to 8 of 500 mah.

With the 120 mah battery pack it can slow up nicely. The guy strings have a lot of drag. If the wind is really high (3 miles an hour!) I use the heavier pack and can fly longer too. It will take off in about 20 feet and retains all the good handling qualities that the little one has. It feels solid in the air and gusts don't seem to bother it as much as the Stubenflege or even the Litestick.

Try to keep the same wing loading as the little one. I would suggest using the Speed 280 instead of the 400 though. It is a lot of fun to experiment with this stuff and the price can be held to a minimal amount. You don't need to use the expensive carbon rod.

Lots of luck,
Ben
Ben Lanterman is offline Find More Posts by Ben Lanterman
Reply With Quote
Old Jul 06, 2001, 10:49 PM
Registered User
Ionia, MI, USA
Joined Feb 2001
61 Posts
I've built a 34" x 12" version of the Kolibri and I fly it outside with much success. It has a V-tail based on the Tiny design expanded to 10". It tracks staighter and is more responsive than the original. I've also had a conventional tail on it and they both control well. The dehedral in the wing is created by a single piece of fishing line from tip to tip. The wings are reinforced by struts of balsa CAed to it similar to a Cub or a Cessna. The original used to tuck in the wings in a dive before I had the struts. It was very interested and yet disturbing to see the plane FLAP its wings in a 45 degree dive! The fuse is .24 dia CF tube. Power comes from a GWS-B DX with a 10x7 APC slowflier prop or a Titanic Airlines 3:1 280 and a 8x7 APC slowflier prop. It can haul anything from a 6x50mah to an 6x720mah NiCd! My favorite combo is:

Jeti 110 esc
2 hs-50 servos
feather rx
gws-b dx w/ 10x7 APC
6x110mah battery
graupner mixer
LS landing gear (saves the prop)
AUW = 8.0 oz
Wing loading = 3.0 oz/sq ft

This combo makes for good top speed and a good climb rate also. Loops are achived with a small (5 deg.) dive. "Rolls" are possible but are EXTREMELY sloppy with both tail group designs. It can also be flown indoors in this configuration. For a park flier version I use:

Titanic Airlines 3:1 280 w/ 8x7 APC
FMA Digi30 esc (fried my Jeti 110 )
2 hs-50 servos
feather rx
graupner mixer
6x720mah NiCd
AUW = 13-14 oz
Wing loading = 4.5-5.0 oz/sq ft

You'll need to make the struts out of .06" CF in order to support the extra weight. Battery will also need to be velcroed onto the top of the motor stick to prevent ejection at the bottom of a loop. I've never tried a 400 direct drive but it sould work OK. The wings may tuck at high speed tho...

Greg
silencer is offline Find More Posts by silencer
Reply With Quote
Old Jul 08, 2001, 07:17 PM
Registered User
San Diego
Joined May 2001
24 Posts
Well The parts will be in tomarrow, wish me luck. I decide on a 2.5 scale and am going to run the standard size reciever and servos and 7cell 500mh batt with the standard zagi esc and prop, I doubt it will fly and if it does it will just go way to fast but i want to experiment.
St0rmBringer is offline Find More Posts by St0rmBringer
Reply With Quote
Old Jul 29, 2001, 05:32 AM
Registered User
Teddington, UK
Joined Dec 1996
275 Posts
St0rmBringer,
did you ever get this going? I was thinking of a speed 400 Kolibri and thought I'd check the forums before I tried, nice to know someone else had the same idea.

Barny
ybanrab is offline Find More Posts by ybanrab
Reply With Quote
Old Jul 30, 2001, 05:25 PM
Registered User
San Diego
Joined May 2001
24 Posts
Just so everyone knows I buildt a 2.5 meter kolibri, it flys just fine with a 400x motor and sub standard sized servos, no 81's here they just don't hav eht juice, I did use a carbo nrod for a main fusaloge through not the brass on, the plane came out really light and have had to add a little weight to it to keep it level in flght if not it just wants to lift. I can almost thermal it off the blacktop at the local school on a really hot day whicih is really coll, I have yet to run out the batteries 500a's out of a standard 400 just becasue its really hard to see when it gets about 400 yards from me, but some colored seran wrap will fix that, you can run real cheap servos and recievers becasue the weight is not that big of a deal, I have a 1700a pack off a 400x that I might try as well as a speeder prop to give it some real omph for getting down out of the sky couse getting up is not a real problem.

Next project is to make the fusaloge interchagable with some other wings I have, I crashed my early monarch A and creamed the fusaloge and think a stick with a obotchi covered wing would be real cool in flight. Plus it would cut down on the weight for free hand lanch.
St0rmBringer is offline Find More Posts by St0rmBringer
Reply With Quote
Reply


Thread Tools