The RTP (Round The Pylon) flight system is a method of flying electric powered model aircraft in restricted spaces, both indoors and outdoors. The models, which are tethered to a central pylon, can be controlled by the "pilot" who has full control of the model at all times without the use of a radio.
A wide range of aircraft types can be safely flown using this system, Scale or non scale, single or multi motor as well as ducted fans. So even the very latest jet types can be successfully flown indoors such as in a sports hall. The tether lines which are also used to convey power to the model, can vary in length from 3 metres to 10 metres (10ft to 30ft) to suit the space available.
Most of the motors used for R.T.P models are rated 12 volts DC so that car or motorcycle batteries can be used as a power source, although the domestic AC mains supply can be used with a suitable DC transformer.
...from R.T.P. Electrix.
Round the Pole flying has also been done with planes powered by Jetex type rocket engines.
I made one for my kids a few years back. It was lots of fun! I used the wall wart and speed control from a HO scale slot car set. The plane was a kit of a Hurricane and about 7" wingspan. I had a 130 size motor in it and it really went fast. We just timed it. 40 MPH with my son at the controls. That's gonna hurt if the cat ever gets it!
The tilt wing was a lot of fun, problem is that going very slow the weight of the line wants to pull the plane in towards the centre. So used tip weight and offset thrustline to keep the line tension. If you flew it too slow the slightest disturbance made it pitch nose up ... then it would fly backwards, the tail "dug in" and it did a backwards outside loop that a 3D heli flyer would have been proud of!
Slow walking pace was the best I could get, also needed a skid u/c as any nose-up "rotation" on takeoff caused it to decelerate and stop immediately (as the motors were then angled back!). So it had to lift off in a completely flat attitude.
With the wing horizontal it was ballistic, most people hid behind tables!
You can easily DIY it ... you just need a power source (transformer or large 12V battery), slot-car hand controller, some fine insulated wire (you can strip this out of telephone cable), couple of ballraces for the pole head, broom handle pole, plywood base ....
I've flown RTP models with all sorts of scavenged (free) electric motors ... from fuel pumps, hair dryers, even old servos (very small & light models).
My club bought a power supply that went up to 48V output ... with long thin lines there's quite a lot of voltage drop. But for short lines a 12V transformer or battery is OK.
Excellent diagrams. A sliding resistor like that (rheostat) is durable and good for high power setups, but a slot car hand controller ("Scalextric" brand in UK) gives much better control. I have two different versions, one gives precise control with small motors but the other will handle more current, so better for twins etc.
Yes the hook is on the CG - most RTP models are very nose-heavy as the motor weighs more than the rest of the plane! The only one of mine that balances "properly" is the tissue covered slow-flier ... you can unhook that from the lines and it glides beautifully. The flying surfaces are actually from a Keil Kraft Ajax vintage f/f rubber model!
You normally leave the hook "long" so you can fine trim the model by bending it a little up/down and fore/aft. If you bend the hook up, the plane flies banked inwards towards the pole which looks more natural. Bend it down and the plane flies with wings flat or even banked out of the circle, which looks really weird!
Bend the hook forward and the plane tends to turn (yaw) in towards the pole, back and it flies with the nose pointing straight ahead or even out of the circle. This can help keep the lines tight on takeoff (as can making the outer wheel on the u/c turn less freely, or even not at all ... assuming you're flying off a hard & smooth indoor surface).
I have built and flown like 30 of these small airplanes, all fron simple 3 balsa piece planes and one motor to a fully built up 4 motor Hercules, though I used 4 meter long wires so I had to find a 10*10 meter area to fly it :/
I still have a Neiuport someware and the pole, gotta try if the setup still works, was about 2 years since I flew it last time.
I have a bunch of plans for some simple planes, here is a link to one of them, print it so it fits on a A4 paper and just build it from plan...
Found a pic of the Hercules in an early building stage, the Barnstormer (plan posted above, called "Pink Panter" there, original name is Barnstormer) also shown on pic.
Both flew great! The Barnstormer does loops and wingovers really nice!
When I was a kid in 1st Andover Air Scouts we did this thing called 'round the pole' flying. We made these Jetex powered planes which we flew aound a pole on a stand in the middle of the hall. The white smoke that spat out of the little engine was probably deadly, and the hall was thick with the stuff......
Click on photograph for a larger version.
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