Icare-RC.com's Rainbow Autogyro Review - RC Groups

Icare-RC.com's Rainbow Autogyro Review

Jeff Williams pays tribute to Juan de la Cierva in this article on the iCare RC Rainbow autogryo. Thank you Senor de la Cierva!

Splash

Introduction


Rotor:1080 mm (42.5")"
Flying Weight:620-700 g (21 - 25 oz)
Length:950 mm (37.4")
Servos:Hitec HS81MG
Transmitter:Futaba 10C
Receiver:Spektrum 6100E
Battery:3 S LiPo 1300 - 1800 mAh
Motor:Common Sense RC E5-M-18
ESC:Common Sense Z-20
Available From:Icare RC

Always looking to try new things in this hobby, a couple of years ago I found myself taking the "autogyro plunge." From my first whirligig flights, I have considered myself hooked. Autogyros have several qualities that draw me to them: They are very unique, present new and exciting challenges that make it great fun!

Kit Contents

The kit arrives in an extreme state of readiness. This kit includes some of the nicest prebuilt wood assemblies I have seen in a balsa model. The wood is absolutely beautiful. Part of me thought wood this pretty should be stained, but a "provincial" stained whirlybird may look out of place on the flight line. All the parts are precision CNC milled and assembled at the factory. The "kit" comes assembled in essentially four sub assemblies: the fuselage, tail section, rotor and mast assemblies.

The level of prefabrication in this "ARF" is very high. The completion for the build is prep and paint (or film covering) final assembly and gear installation. If there was a downer in the package, it would have to be the instructions which have been translated from what appears to be an Eastern European language into English and can be very comical at times. But it does come with some VERY nice diagrams that show where the parts go. The entire Rainbow can be assembled without even reading a word of the text, however, I do recommend you read the instructions.

Assembly

Painting

The Rainbow goes together quite quickly. All the subassemblies are ready for paint/covering right out of the box.

I decided to test out my new airbrush on the Rainbow. I purchased a can of Deft Sanding Sealer and a can of Deft Sanding Lacquer at my local hardware store. These products do a wonderful job of prepping balsa for paint and are also great for fiberglassing balsa airframes, but it will eat the foam away on foam planes. It also has some very strong fumes, so be sure to use in well ventilated areas.

The process is very simple: Sand the part to be painted smooth, and apply the Deft Sanding Sealer and allow to dry. Once the Deft dries, the balsa will have small fine "hairs" that will be visible which needs to be sanded down down and more Deft Sanding Sealer applied and allowed to dry. I rinsed, washed and repeated until I could allow the sanding sealer to dry, and the part was no longer "fuzzy."

Then, I applied a coat of Deft Sanding Lacquer and allowed it to dry, sanded and repeated. I used 3 layers of lacquer on the Rainbow. The weight gain was minimal. Once I applied the last layer of lacquer, I painted. I also sealed my paint with a quick shot of clear gloss spray.

The fuse, rotor mast and even the rotor head are ready for assembly, however, none of them are painted. The most time consuming portion of the build is the prep and painting of the assemblies. Traditional film covering would work very well on the Rainbow also.

In prep for the painting, I disassembled the rotor assembly, making sure to rebuild the unit correctly once the painting was complete.

Rotors

knew from experience that the rotors are often the first parts to take a beating. One of the biggest obstacles I faced when learning to fly autogyros was keeping them upright after a landing; they can tip over while you are learning, often while the rotors are still spinning. Spinning rotors can lead to splintered rotors which can lead to a bad day which I wanted to avoid by adding some durability to my rotor blades.

I prepped the blades to be fiberglassed using very light weight cloth and Deft Products’ sanding sealer and lacquer. In order to save weight, I chose to only fiberglass the bottom of the rotors to add some strength and only sealed and painted the upper surface of the blades. This method has worked well for me. You could also use traditional shrink type plastic film coverings, or a tip I received from a heli flying friend: heat shrink tubing of the appropriate size.

Fuselage

The fuselage on the Rainbow is a very typical "boom and pod" arrangement. The forward fuse is traditional built up balsa and ply followed by a carbon fiber tube, and the tail units are simply sheet balsa. Since the forward fuselage is already complete out of the box, I checked the glue joints to ensure it was ready for paint, then painted it.

The carbon tube slides through 2 braces, through the rotor pylon and up to the landing gear former and is CA'd into place on the gyro. One word of caution here: when installing the fiberglass boom into the fuselage, be very gentle with it; my boom wound up splitting on me, and I had to replace it. I do not attribute this 100% to the boom as I can be quite ham-fisted at times, but be easy with the boom.

When I first saw how the landing gear is installed, I was a little skeptical; The gear is simply sewn onto the former using needle and thread. I lashed the gear to the former and then hit the thread with some thin CA. I am very happy to report that to date, the gear is holding very, very well. Sew on!

Tail

The tail is nothing more than 3 sheets of 1/8" CNC cut balsa sheeting. The bevel for the elevator is already cut into the elevator. The vertical stab must be glued into the horizontal stab and then covered. I sanded down all components, applied the DEFT in prep for painting, glued the vertical stab to the horizontal stab and then painted it. I installed the control horn into the elevator before installing the elevator, with 3M storage tape, onto the horizontal stab.


One point worth mentioning is that the carbon boom lays to the right of the vertical stab, so the vertical stab does not mount dead center of the horizontal stab. I had a few second takes at what I had before me. No worries, the notches cut into the horizontal stab are indeed in the right spot.

Radio Installation

The Rainbow uses only "aileron", throttle and elevator control to guide it through the air. Both the aileron and elevator servos are installed into the rotor head pylon. The installation of the servos showed one of the small things that to me, make a kit shine above others. The servos are installed (one per side) of the pylon, and the designers had the foresight to include a channel for the servo wires to exit. While not a super huge detail, it is clearly what separates the men from the boys in my eyes.

I went with Hitec HS-81s for roll and pitch on the Rainbow and had to enlarge the servo locations in the pylon just a touch to allow them to fit in easily. A few swipes with a flat file enlarged the holes perfectly. Many of the smaller servos would have also worked very well - Hitec HS65MG's would have fit perfectly. Something like an HS55 would would be plenty for the elevator I would imagine but on the rotor head, you need a little more substantial servo.

With servos installed I moved onto the motor, ESC and receiver installation. I chose a Common Sense RC E5-M-18 motor, Common Sense RC Z20 ESC and decided to guide the Rainbow with a Spektrum 6100E via my Futaba 10C with a Spektrum module.

Completion

Final linkages must be installed and adjusted. The kit includes a white pushrod sleeve to run to the elevator, which I glued to the tail boom and then painted black to hide the white tube on the black boom.

The center of gravity was easily attained with the location of the 3S 1100 lithium pack I am running.

Flying

The Rainbow will take off in the traditional rolling takeoff fashion and can also be very easily hand launched. I wanted to make sure I could correct for any errors that may happen during the take roll, so I opted to give it a rolling takeoff.

The Rainbow eased into the air very easily in around 25 feet with a little throttle and only required a little right and down trim to have her flight straight and level hands off.

Subsequent flights have shown the Rainbow to be an absolute sweetheart. I have gotten enough time on her that I am extremely comfortable with her in small spaces and fly her out of my backyard quite often.

The Rainbow is a great "windy day" flier. In any sort of wind, takeoffs and landings can be accomplished almost vertically.

Basics

The Rainbow flies very well and is capable of most "lazy" style maneuvers.

It will loop, and it will also roll but it does not seem to enjoy it too much. It is much more at home cruising around with the "dirty side down."

There is no noticeable "stall" with the Rainbow. To stall it, you must first get the rotor to stop spinning, and on the Rainbow, that is quite a feat. I was able to get it stopped with continued attempts, but once the nose falls, the rotor is already back at flying speed.

Taking Off and Landing

You can ROG or hand launch the Rainbow easily. The light weight of the rotor will allow for rotation to be gained very quickly. Even the slightest breeze will produce enough lift for the Rainbow to be hand launched. For a rolling takeoff, since the Rainbow has no rudder, simply point her into the wind and apply the throttle. In a manner of seconds she will be airborne and reaching for the skies.

Is This For a Beginner?

Beginner pilot? Nope. Beginner auto gyro enthusiast? Sure. This would make a great initial auto for a first time autogyroist. The ease of construction coupled with the simpleness of the setup all lend to a very good first timer autogyro.

Flight Video/Photo Gallery

Downloads

Conclusion

If you are giving auto gyros a thought, then you would do well to give the Rainbow a once over. The very simple construction, high quality craftsmanship and relatively inexpensive power system of the Rainbow all add up to be a great value for the owner.

It is a wonderfully behaved auto gyro with no bad tendencies other than perhaps calling on you at all times to take her flying!

Pluses:

  • Quick assembly
  • High Dollar/Excitement ratio
  • EXTREMELY nice kit

Minuses:

  • Carbon fiber rod shattered during install
  • Translation of instructions into English is problematic, but the entire aircraft can be built with the high quality diagrams included in the kit.

===============

Last edited by Angela H; Jun 09, 2009 at 07:29 AM..
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Jun 08, 2009, 09:18 PM
Hooper, full throttle!
Tommy D's Avatar
Great review.... my Pop's loved these things!

Toss some LEDs on it and have a VERY unique night flyer!!

Tommy D
Jun 08, 2009, 10:16 PM
AND FOR MY NEXT TRICK....!
jodini's Avatar
Thanks for doing the review! Looks like a real fun gyro! Great right and left turns! NICE!
Jun 09, 2009, 10:27 AM
Registered User
lrplin's Avatar
It looks fun to fly with, however it seems too expensive for a few piece of woods!
Jun 09, 2009, 11:12 AM
Registered User
Kmart's Avatar
Great review, verry nice job!!
Jun 09, 2009, 12:29 PM
↓↘→ + (punch)
theKM's Avatar
Quote:
Originally Posted by lrplin
It looks fun to fly with, however it seems too expensive for a few piece of woods!
the dollars are mainly towards the head and the rotors... sorting them out is really non trivial.
Jun 09, 2009, 02:24 PM
Stress Be Gone
GBR2's Avatar
What size prop did you use on the motor and what brand?
Jun 09, 2009, 04:42 PM
The sky is my playground.
Dora Nine's Avatar
What a neat model!
Jun 10, 2009, 03:10 AM
Registered User
will it be easy to add a servo for the rudder ?

Could somebody explain to my how the controls are working ?

I don't know if the throttle control the speed... I think this is the elevator's job, isn'it ?
Last edited by twinflandres; Jun 10, 2009 at 03:28 AM.
Jun 10, 2009, 04:29 AM
Registered User
PeterO_UK's Avatar
I don't understand why someone would produce a kit like this without a full direct control head. A rotor head with fixed fore-aft tilt makes ground handling and ROG in anything other than calm winds much harder to control, and not being able to tilt the rotor fully foreward (to slow it down) after a landing makes a "blow over" very hard to avoid. It's a shame that an otherwise good looking kit is spoilt by this design failure.

PeterO_UK
Jun 10, 2009, 08:38 AM
Lets break some props :D
joseico90's Avatar
A servo tilts the rotor side to side to give you "aileron control"

The elevator gives you "up and down" or pitch control,

The throtle is as normal, when more than enough power for level flight is applied the gyro should climb, and the other way round.

For what I can see some of these so controlled gyros fly quite well, here is one with a Depron rotor.

https://www.rcgroups.com/forums/show...8#post12424812


Quote:
Originally Posted by twinflandres
will it be easy to add a servo for the rudder ?

Could somebody explain to my how the controls are working ?

I don't know if the throttle control the speed... I think this is the elevator's job, isn'it ?
Jun 10, 2009, 08:43 AM
Lets break some props :D
joseico90's Avatar
Isn't it just!

I love it!

Quote:
Originally Posted by Dora Nine
What a neat model!
Jun 10, 2009, 08:46 AM
Lets break some props :D
joseico90's Avatar
Here is a similar desing with lights!

Check out the many videos on that thread.

https://www.rcgroups.com/forums/show...8#post12424812


t=1008868&page=8#post12424812
Quote:
Originally Posted by Tommy D
Great review.... my Pop's loved these things!

Toss some LEDs on it and have a VERY unique night flyer!!

Tommy D
Jun 10, 2009, 10:57 AM
Fly it like you stole it..
Tram's Avatar
Quote:
Originally Posted by Tommy D
Great review.... my Pop's loved these things!

Toss some LEDs on it and have a VERY unique night flyer!!
Yeh, I'm sure I'd manage to plow it really nicely at night.. I may have to try it though.. Maybe SEFF '10!

Quote:
Originally Posted by jodini
Looks like a real fun gyro! Great right and left turns! NICE!
It is a ton of fun.. Great for a small area.

Quote:
Originally Posted by lrplin
It looks fun to fly with, however it seems too expensive for a few piece of woods!
If you price out similar gyros, the price is very comparable.. Most gyros, as theKM pointed out, the price goes to the head and blades.. Other than that, this is literally the nicest wood "kit" I've build.

Quote:
Originally Posted by kmart
Great review, verry nice job!!
Thank you.

Quote:
Originally Posted by GBR2
What size prop did you use on the motor and what brand?
I will run out to the trailer and see (the gyro found a permanent home there).. I *think* it's an 8x6E.. I am 100% sure it is an APC Electric prop..


Quote:
Originally Posted by twinflandres
will it be easy to add a servo for the rudder ?
You could add rudder with very little extra work, I would think..

Quote:
Originally Posted by PeterO_UK
I don't understand why someone would produce a kit like this without a full direct control head. A rotor head with fixed fore-aft tilt makes ground handling and ROG in anything other than calm winds much harder to control, and not being able to tilt the rotor fully foreward (to slow it down) after a landing makes a "blow over" very hard to avoid. It's a shame that an otherwise good looking kit is spoilt by this design failure.
I thought the same thing.. I was curious as to why they would do this.. Having flown a handful of "conventional" gyros I was ready to see how this one would fly..

After flying it, I enjoy it.. It's fun..
Jun 10, 2009, 11:04 AM
Registered User
Kmart's Avatar
Quote:
Originally Posted by Tram

Thank you.
You all are setting the bar so high, I hope I can keep up!!


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