RC Groups

RC Groups
    Scratchbuilt Indoor and Micro Models
        Question Best of both worlds!

#1 PrasadL Feb 15, 2005 03:13 PM

Best of both worlds!
I fly in a park near where I live most of the time and love my speed wings and 3D planes. But they are too big and too heavy to fly indoors. So when I started to fly indoors I had to learn to build small planes that fly beautifully indoors but canít tolerate even slightest breeze so outdoor flying is impossible most of the time. This is really frustrating because I do not have an access to regular indoor venue. So I started to focus on planes that can be flown indoors and outdoors. "My Convertible" is a result of that experiment.

I would like some help to find out best design criteria for hybrid planes that fly indoors and probably under moderate weather outdoors equally good. What design parameters are critical to this kind of design (weight, wing loading, size ext...)? What type of power system and controls are most sailable?
Thanks for your help. :)

#2 RobinBennett Feb 15, 2005 03:24 PM

Most people faced with the same problem just have two planes ;-)

I guess that what you need is a wide speed range, indoors slower is better but oudoors you need to fly at least as fast as the wind, if not twice as fast.

A low aspect ratio is good for a wide speed range, as the short wing is easier to build strong enough for higher speeds and has a gentle stall at low speeds.

It would help to be able to strap on a bigger battery and higher-pitched prop for more weight and speed outdoors - maybe just moving from 2s to a bigger 3s battery would do it but if your motor can handle the extra power it's heavier than it needs to be indoors.

#3 derk Feb 15, 2005 03:32 PM

try the p-nut by dave robelen in micro flight magazine. 30 mph top speed but slow enugh to fly in a gym.


#4 PrasadL Feb 15, 2005 05:06 PM

RobinBennett, Two plane solution doesnít work for me because I donít want to waste precious indoor flying time I have setting up the plane.

Derk, That is a great model. Never thought KP00 can propel anything to 30mph and actuators can control anything that fly at that speed! I can learn from that design. Also I learn from my experimentation plane with short span and larger cord can tolerate wind better. My design that has 23in span 9in cord that floats indoors flies well outdoors with moderate winds. Also flat wings with in-line tail tolerate wind better than under cambered wings with off line tail. I am also working on a flat wing model with flaps to improve indoor flying characteristics dynamically by deploying variable flaps to simulating wing camber.

#5 dhurd Feb 16, 2005 06:52 AM

There is video of the P-Nut here.

Bear in mind while you are watching it do rolls that this is a RET plane.

Dan Hurd

#6 ronmar1 Feb 16, 2005 07:10 AM

Nice plane and very nice flying Dan. That'a a great video. I wouldn't want to be the camera man! Must be a nightmare trying to keep up with the plane.


#7 dhurd Feb 16, 2005 07:18 AM

Actually I was the camera man. It was difficult trying to keep the plane in the frame. The pilot was Dave Robelen himself (the designer). He's the one that walks out and picks it up. Even though the plane could fly extremely fast Dave also showed how it could slow down and behave nicely as well.


#8 ronmar1 Feb 16, 2005 08:30 AM

Good job on both accounts! I enjoyed the video. The plane really responds well.
Now if I can just get all this stuff I've bought from DWE in the last couple of weeks to do anything half that well I'll be flying!!! Literally!

#9 PrasadL Feb 16, 2005 05:30 PM

Thatís a cool video Dan. I wish my indoor venue is that big!
Anybody carry kit version of this plane?

#10 dhurd Feb 16, 2005 08:43 PM

We do have Dave's permission to kit the plane. Perhaps we will move it up on our current list of kits we are going to produce. The biggest issue would be the wings. His wings were made from bluecor foam with an MA409 airfoil. Getting the taper he has on the ends would be difficult to do with a foam cutting machine. Maybe we just put the wings in the kit and let people sand the taper in themselves if they want it.

Dan Hurd

#11 PrasadL Feb 17, 2005 08:17 AM

That is a good idea. But the wing is the main reason I asked for the kit. I too thought it is too complicated to make. RTF planes from companies like Horizon Hobbies have inexpensive, light but complicated shape foam wings with strong plastic coating. How do they make those wings?

I think it is time to bring more aerobatic planes to micro arena since there is a lot of interest in 3D flying. I see lot of people try desperately to fly their big 3DXs indoors during our indoor meets. They would love a micro 3d if available. At the moment only thing that is available is Micro Edgeling from BSD.

#12 Dave Wulff Feb 17, 2005 08:46 AM

Foam wings with complicated shapes are molded, not cut. It takes a high volume of sales to justify the expense of creating a mold. Blu-core type foam sands easily, and sandpaper is cheap...tough combination to beat. :)


#13 epilot Feb 17, 2005 09:12 AM

The key factor in having a succesful 3D plane seems to have a high thrust/weight ratio. If you can build light enough just scale down the current 3D models and fit the lightest equipment you can get together with a powerful geardrive.



#14 PrasadL Feb 17, 2005 11:18 PM

Cloud9 column of latest RCmicroflight mag shows Gary Jones holding a foam micro 3D model (Mix 18 ?) fitted with his MicroDisk motor. Where can I find more info on that model?

All times are GMT -5. The time now is 04:03 PM.