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Hi Gary,
 
Sorry, wasn't ignoring you, just forgot to reply!  Yup, I'm over in Thames Valley with the ATC.
 
Any idea of the ratings on the small motors?  I found some similar ones, same size, but they burnt out within about a minute.  I have a feeling the amp rating was too low.  Price of what you found seems about right, 75p or over a fiver?  No question which is better value!
 
We've yet to completely kill any of the Ballards motors but they are all slowing down.  The larger ones (we only have two) don't get used as much so are still fine.
 
We haven't broken a prop in a while, not since we tried to get it to run outside on the parade square which was rough tarmac.  It's been resurfaced this year and may work better I guess, but I think the wind at the moment might be more of an issue.  Not to mention the rain!
 
I'm still plugging away building planes and am planning on running our BoB week this month.  I'll try and do some photos once we're up and running.
 
As a thought, the troops built the hovercraft plan from QEFI last month which was a good intro to R/C.  Small, electric, depron and good for hand/eye co-ordination. 
 
Jon
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RTP. I did some back in the 50s but in those days it was rubber power and Jetex. Jetex speed was quite something in the Regents Park club. They ended up with a Jetex motor with a sheet copper wing, a wire tailboom and copper tail. The charge was cut with grooves all round and burnt about three tiems as fast as normal Everyone down behind tables up on their sides and the stink was impressive.
 
After speed became too fast to time we built solid models and hollowed them out. I had a Supermarine Swift that flew like a dream.
 
Rubber powered models could be flown for speed, duration or scale. In fact that was the only way that I ever got the KK scale models to fly.
 
 
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Jon,
 
The motors have to be 12 Volt, the power supplies are normally rated a bit higher to allow for losses in the thin lines to the aircraft and the variable resistor type controllers. Spare Scalextric or model train motors work well  with small push on props from Ballards.
 
Switching controllers are much better if you can get them or make your own if anyone is into electronics PM me for a circuit, they are very simple and cost about £3 to build. Much more positive control, lower losses, and handle about 15 amps easily.  
  
Chris. 
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Jon,
 
Just posted the circuit and details, it's got me fired up now. Just might lob a couple together for when my mate comes round, profile Spitfire and ME109, or SE5 and Eindeker, for a bit of garden combat . Plastic electricians conduit from the B&Q makes a simple pole with fittings about £8-00 enough to make 3 or 4 poles.
 
Chris.
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  • 2 months later...
Hi all I am a Air Cadet Sgt and have been given the task of sorting out some flying activity indoors and found your topic quite intresting.
 
I have been on the Ballards site and have ordered all of the equipment we need.
 
I have been looking in to this for some time so dont think its just an off the cuff thing.
 
I am intrested how you do combat as i feel that it would enhance the hobby, as you have said its a boy thing.
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Hi Graham,
It's nice to know that i'm not the only one who gets voulenteered for things. Does your squadron have a smooth handled broom as well? Ours has a whole cupboard full to be issued by the C.O.
 
 We have had some success with flying our Ballards "trainers" and a couple of thier profile Bf109's. Unfrotunately we can only manage 3 meter lines maximum in our hall. This is a bit of a shame as it means a very short "circuit."  This really presents problems when flying combat with the more powerful aircraft, as they are really whipping round.
 
So far then we have had to limit combat to the trainers. We compete towing a 500mm fishing line with a 500mm tissue streamer. The rules are simple, but difficult to stick to and judge. They are:-
1. Start on the ground at 180 degrees from each other.
2. Take off and take station at 180 degrees to each other.
3. When both aircraft are in the air and in formation the "judge" calls "begin."
4. Each combatent tries to catch the other and cut their streamer. This can be done by rapid climbing, diving, accelorating, or slowing.
5. There is to be no aircraft to aircraft contact.
6. This continues until one pilot looses all or very nearly all of his streamer or the time for each bout has elapsed.
7. The judge may be called on to measure the remaining streamer the longest left being the winner.
Another variant we have yet to try is a "scramble." One in the air circulating at altitude, when "Scramble" is called the other takes off and engages the enemy. We do have Bf109's, Spitfires, and Hurricanes. So 70 years on we can refight the Battle of Britain.
 
Obviously rule 5 is very hard to achieve, but we have found charging a "propellor deposit" does help to focus the cadets on not colliding. If the cadet breaks a prop then he/she looses thier deposit.
 
We have found that it as well to keep the double sided tape and super glue to hand during combat sessions. We also keep a couple of drink cans and a pair of scissors to hand as well. These later (with the double sided) tape make great add on elevators or flaps. Also handy is the soldering iron as the wires frequently let go, and lastly a number of replacement fuses for the PSU's and speed controllers.
Each combatent team can then "tune" the flight characteristics of their plane. It teaches a great deal about trimming.
 
At the moment we are in the proccess of building some scale models for demonstration flying as well.
 
If you want to PM me I'll pass on my e-mail address, and we can swap all sorts of information, plans etc. I'll see If I can find some photo's as well.
 
Cheers
Gary
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Gary
 
Your fuse blowing issues sounds to me like an issue with the lines insulation.
 
Try a set of new lines.
If that sorts it then either ditch the old lines or fit new wires.
Look around the point where the lines are tied around the strain relief (commonly an insulated paper clip).
You could always separate the lines and paint the lines and strain relief with insulating varnish to return the insulative properties.
Of course now females are in the ATC, one or 2 may have some nail varnish you could use.
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I have got the pole and bearings and wired them up I have sorted all the plugs and stuff but I dont have the controller yet.
 
When i do get the controller what is the wiring from transformer to controller to pole. As in is the controller inbetween the pos on the transformer and the pole and the neg just goes direct to the pole.
 
Gary I am lucky enough to have a co who knows what family time is required to keep the said family happy. I am as it were able to select projects to do and this one is part of my life passion for flying.
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Hi Graham,
Generally speaking you put the controller in between the PSU and the pole, as you have described.
If using Dave Ballards power supply and controler it is just one two pole (audio phono) connection out of the PSU, into the controller, and then to the pole.
The Ballard controllers are very well made and do the job well, however it takes some getting used to having a rotary throttle.
Easier to use are the old fashioned scalextric trigger throttles, but they are limited to lower current motors. If you use that type of controller then you would be interupting the pos with the controller, and taking the neg to the pole. As I say they start sending smoke signals if you try to put too much through them. Don't ask me how we know.
 
Gary
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Hi, we flew rtp at the club I was a junior member of some 30+ years ago and - in common with the unanimous view on here - found it involving, absorbing, and huge fun.
 
We had success with various models but one I remember particularly fondly was a Ray Malmstrom designed cartoon scale SAAB J29 Jet, powered by a slot car motor turning a prop in a slot cut into the profile fuselage
 

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Hamish thanks for that i will be all over it in a few days. The pain is that i have won 2 transformers on ebay and one is great.
 
Gary thanks for the confirmation I can wire it all together now.
 
I have got 4 old type controllers from ebay and all for 99p. I have started building a helldiver and cant wait for the flying to start
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Hi Guy's,
 
You seem to be getting fairly well sorted with the power supplies, it's important to use a slow blow fuse in the line between the controller and the supply. It's very much preferable to change a fuse rather than to burn out a controller or power supply.
 
With regard to the controller. As I've already said, they can be built very cheaply using off the shelf components, with the advantage of not being restricted to resistive types, thereby wasting power and being more positive. Micron RC may still sell stick units that can be built into self made controller boards for throttle control.
 
There are systems for three wire control to add elevator control as well as throttle, I'll see if I can sort out some diagrams.
 
Chris.
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Hello to RTP fans.  I have just discovered this thread and I am pleased to see that RTP is still alive and well.  I developed an interest in the system years ago, especially as a means of introducing school children to model flying.  I have also noticed that an ancient article of mine on the topic also remains on the web: http://www.ctie.monash.edu.au/hargrave/mccarthy_rtp.html

This is sadly in need of revision and updating, but some of the  ideas worked well back then, especially the use of simple cardboard models as a way of demonstrating the basic setting up of an aircraft: CG; wing and tailplane incidences; wing loading; simple aerofoil effects; control surface effects, etc. All of these could be implemented and the outcomes immediately made apparent!  With every group I would have the model scurrying around on the floor (lots of jeers) then stop it, tweak the elevators, and up she would go to gasps of amazement. Getting small groups of students engaged quickly in building a cardboard model and flying it was a plus for this approach to RTP.
 
Jono's comment on 11/8 brought back unpleasant memories: "The lacquered wire is an issue although careful storage makes a difference." I recall trying to solder the stuff in the middle of a session - it was always kinking and breaking.  I found that a cheap alternative was a pair of wires stripped from grey comptuer linking cable.  They were somewhat heavier of course but as they were joined as a single unit the air resistance was probably about the same.
 
Good luck with RTP.
Peter
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  i have just picked up my second transformer and cleaned it up nice. Good clean power smothed and with an easy dial from 0 up to 30 volts.
 
My other transformer that was for a train set was found to be 16v ac so i have built a nice box with a bridge rectifier a switch and pole plugs ready for use.
 
I have now doped the hell diver and i am always impressed with the way it does its job. I think a couple of hours with the soldeing iron and i may have it all flying.
 
Peter and others have mentioned the flying wires shorting so i am now worried about the same problem. I am using ballards flying wire or will be when i get going so how do i connect it.
 
2 wires soldered to a nice little plug  but how do i connect the wire to the plane without them being shorted on the hook.
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"Peter and others have mentioned the flying wires shorting so i am now worried about the same problem. I am using ballards flying wire or will be when i get going so how do i connect it."

Graham,
I used a wire hook (usually from a paper clip) that had a length of plastic tube cut from some electrical cable squeezed over it. I simply tied a knot in the "flying wires" and looped this over the hook. Never had any shorting or disconnection problems.  Having some difficultyposting pictures on this forum.  Much easier to explain than verbal description!
Peter



 



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 This model fuselage is typical of the cardboard jobs we made.  Foam blocks were glued in with hot melt glue as formers. The paper clip hook with insulation cover can be seen clearly. The "flying wires" are made from a pair of wires stripped from grey multistrand computer connection cable. I think the female plug was salvaged from an old computer too.
 
The cardboard control surfaces were created by simply cutting in the appropriate places and bending the sections up or down.
 

.
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Simple models in RTP can be fun but if you are seriously daft you can go the other way.
My last (to date) RTP was the beautiful MB5.
Just 24" span with two slot car motors driving scale contra rotating props. Built almost entirely from 1/32 sheet I originally intended to have a retracting U/C as well but chickened out as just too risky, but the legs do have internal springs.
It weighs just 4.5  oz and flies well but keeping all those blades clear on landing is quite a nightmare.
It still works although not flown for many years.
Quite an impressive noise even if its nothing like a RR Griffon.
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