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Where are the VTOL's

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Old 01-30-2004, 12:36 PM
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Scratcher
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Default Where are the VTOL's

Just thought I would start a new thread to see if anybody was working on or has had experience building a vtol. The other threads I found were almost a year old. It seems we have all the technology we need, are people just waiting for the ARF version?
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Old 01-31-2004, 02:52 AM
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Default RE: Where are the VTOL's

ORIGINAL: Scratcher

.... It seems we have all the technology we need,.....
Yes and no. The technology is there but it's not as easy as you may think unless you're just looking at a basic funfly type that launches out of a box vertically. To do a proper hover under control, transition to decent forward flight and then back to hover is not that easy. I'm thinking of models that actually look like a Harrier or similar. The systems to maintain a stable and controllable hover take a lot of consideration and engineering.
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Old 01-31-2004, 10:37 AM
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Default RE: Where are the VTOL's

There were basically only three Pogo-stick designs which became well known during the 1950's and none of which became sucessful. The powerplant is what holds these up today, and then too. Was comment here at RCU better than a year ago, a reader from southeast Asia was developing an electric drive to adapt to such. I haven't seen anything since then except inquieries such as yours.


Wm.
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Old 01-31-2004, 12:53 PM
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Default RE: Where are the VTOL's

It's a very good question. The fundamental issue with a full scale VTOL is the power plant. With R/C, that is not really a big deal (at least nowadays.) There are even good sized electrics that hover no problem. Sounds like a good electric project would be a V22 Osprey.
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Old 01-31-2004, 01:27 PM
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Tall Paul
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Default RE: Where are the VTOL's

Fun flies and 3D planes do this every day now..... they just don't do the "L" part since they lack a support. And the AMA might quibble...
The technology is here.
Any plane that can fly up from a release can also fly backwards down...
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Old 01-31-2004, 05:14 PM
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Default RE: Where are the VTOL's

Been thinking of building the Pogo for a lot of yrs. but the weight thing always held me back. Now with the li poly batts.might just work. Thinking of using the differential gears from electric cars for contra- rotating props if theyr'e strong enough. Another winter project.
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Old 01-31-2004, 05:26 PM
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Default RE: Where are the VTOL's

You say the difficulty is in the transition. What are the few successful designs we have now using for the transition mechanism? I have seen some designs that use modified Heli frames but are they fixed or on a swivel? And am I right in saying any VTOL design capable of vertical lift has more than adequate power for forward flight even with decreased wing area?
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Old 01-31-2004, 06:07 PM
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Default RE: Where are the VTOL's

The most reasonable way to make a VTOL plane would to do a copy of the V22 Osprey. But with little control surfaces behinf the props for control in hover flight instead of the complex cyclic/colective movements of the real one. All it would take is a few more servos, extensions and a good computer radio to do all the mixing. But yes, its quite possible nowadays, I guess that what happens is that there aren't a lot of people willing to invest time and money into a plane that just takeoffs and lands vertically, apart from flying in circles....Although with a little mod this would make a really good 3D plane, imagine tilting one "rotor" down and the other up, ignorant roll rate!!

And about the wing area, since the rotors are tiltable (is the spelling correct??),assuming it's V22 alike, you can always leave then with say 10 degrees up tilt, so they not only provide forward thrust but also a little up thrust, helping the lift further. Another approach would be that since these planes VTOL, they don't need to have large wing areas for reduced stall speed, they need the wings only for forward cruise flight, where not much area is required.
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Old 01-31-2004, 06:36 PM
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Default RE: Where are the VTOL's

Here's a simple model that took me 25 minutes to do in Rhino that further explains what I said (an image is worth a thousand words)
I dind't pay much attention to the correct sizing of the areas and everything, it's just a simple sketch so you can have an idea of what I said in the post above.
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Old 02-01-2004, 12:21 AM
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Default RE: Where are the VTOL's

Here's one:
http://www.corpcomp.com/weeks1/

and another:
http://geocities.com/v22chap/vtol.html

and the best for last:
http://www.awatson1.fsnet.co.uk/
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Old 02-01-2004, 10:20 AM
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Default RE: Where are the VTOL's

EagleOne, nice job on the design. You could even do away with the vertical fins behind the props and still have full 360 degree yaw (with mixed channels) and forward/reverse hover. It would save a couple servos and a channel and unless you plan on doing any precise landing, should be very maneuverable.

Thanks wildnloose, I've seen all three of those sites. I've searched the end of the net looking for new ideas on RC VTOL's. Somebody once mention using a retract mechanism. I know retracts use a servo but does the servo work continuously while the gear is down or up - draining the battery? And do the retracts take up a transmitter knob or are they simple on\off channels? Perhaps the motion of the retracting mechanism would be too fast for the transition to and from forward flight, can the speed of a retract be adjusted?
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Old 02-01-2004, 01:13 PM
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Tall Paul
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Default RE: Where are the VTOL's

Don Incoll in Australia did this successful Osprey lookalike a few years back..
The wing tilt servo was built for the purpose.
Pretty much normal otherwise.
The canard failed in flight though so it went to the local landfill.
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Old 02-01-2004, 02:34 PM
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Default RE: Where are the VTOL's

ORIGINAL: Tall Paul

Fun flies and 3D planes do this every day now..... they just don't do the "L" part since they lack a support. And the AMA might quibble...
The technology is here.
Any plane that can fly up from a release can also fly backwards down...
AMA won't quibble... if the wheels are all at the back... that's the landing gear. If the wheels are on the bottom... that's the landing gear. If you have wheels on the bottom and the top and the back... land any way you want.

Someone made a SPAD PBF with a X formation (essentially 2 pbf's affixed by connecting the square wings at 90 deg to each other right down the centerline)... just for VTOL. Works for the take off and landing... kinda hard to do anythig else with it. Maintaining orientation to which way is up is a pain, even with 4 colors of Coro.
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Old 02-11-2004, 11:55 PM
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Default RE: Where are the VTOL's

well I have an idea that might work for the harrier use a device called the CO PILOT it has a sensor that keeps it level at all attitudes. I thought a bit about this thing. Beginner pilots and expert pilots use them all the time. I saw the ad in the forum sometime ago.
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