Remote-controlled-transmitter for training pilots... tx doesn't transmit, it recieves

[Accu157]

I think I saw it in an issue of model aviation.... I've got an old old transmitter that is pre-1991 regulations... it's useable, but useless, and not something that belongs in a museum either. In the article, it shows how to convert a transmitter to be on the recieving end by putting a reciever in the transmitter, and servos in the radio so the device mimics the controls you put in the model while flying. I'm going to need some help here. I'm not sure how to set this thing up mechanically. It's an excellent training device, the trainee gets to "feel" how to fly the model before they even go up. It's probably the best way to prepare someone before they even go up in the air. I'm going to search the AMA Model Aviation archives to see if there's anything there, but I'd like some more detailed help on this from the guys here too. The transmitter comes with limited expo and I think maybe limited end point adjustment via trim pots. Is there a way I could use those to give expo/endpoint on the servo end to make setup easier? This will be used with a plane that does not have a computer radio nor any mixing, so no conflict on that end. Off to tear out the innards! :o

[amworks]

you mean something like this?

http://www.webx.dk/rc/evo/trainer-wireless.htm

[ZAGNUT]

i rember seeing that article in RCM back in the eighties.

i think the easiest way to go would be to use an old TX that had both gimbal pots stationary and rotated by a yoke system. these were commonly found in sets that didn't have separate trim pots like old cheap 4 channels. this will allow both servos to be solidly mounted to the case. modern gimbals would require the aileron and rudder servos to be mounted to and move with the elevator/throttle axis, not very easy considering the size of a servo compared to a pot.

end point/expo could be handled with the little inline units sold for use between the reciever and servo in the plane itself.



dave

[Gary Warner]

I don't think he's talking about a 'wireless link' trainer system, but more of a 'force feedback' system that moves the tx sticks on the 'receiving' transmitter so a student can get the feel of stick movements-to-effects when a skilled pilot flies the plane in a demonstration.

Cool idea.

I was going to use a synthesizer receiver and make a model plane (just a model - small, not flying) to let me 'look' at other pilot's stick movements as they fly their planes. I like this idea of a receiving transmitter better. It really would give a better feel for what another pilot is doing.

(could be used as espionage on the club show off. ;) )

Gary
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[Accu157]

Gary has the idea right. :) As well as zagnut. However, only two of the gimbal pots are stationary, the others rotate in their location. The transmitter is so big that the rotating gimbal pots are not an issue at all, the room inside is just right, and I've got it all in my head how it'll work, but... I need to get the correct parts, gears, tubes, etc to make this work. Going to see if I can dig up that Model Aviation article.

[Accu157]

Is it possible this isn't the right place for this? I mean, there's really nothing electronic about it, it's mostly mechanical issues. What's a good alternative forum?

[Accu157]

Well, I bit the bullet, and went ahead to convert it... I've already got the right hand side setup! :D Aileron and elevator works! It was pretty easy in hindsight, but oh boy did I stare at it for quite a while. Getting the throttle servo in will be easy, for the rudder, I think I'm going to have to install a bellcrank. This think is going to look like early pre-CCPM helicopter mechanics... ;) It'll all fit.

[Zeta Phoenix]

Please post pics when done!!

-Jon

[AndyOne]

I remember reading an article in an April edition of a magazine that decribed a system for force-feedback to the transmitter sticks by putting receiver and servos inside a transmitter. The article then went on to explain the radio system used to send back the signal. The whole article then exposed itself as a spoof and an April fool explaining that it would be impossible to make a system like this because of the technical problems of sending a high enough power signal back from the aircraft. Who ever wrote this article didn't know much about radio because it was immidiately

In the 1970s during a World champs aerobatic competition the Japanese team had a chart recorder connected to a receiver (tunable presumably) to capture a permanent record of their own and other competitors stick inputs so they could analyse and improve on their performance.

Andy.

[Gary Warner]

The whole article then exposed itself as a spoof and an April fool explaining that it would be impossible to make a system like this because of the technical problems of sending a high enough power signal back from the aircraft.
Andy.

I remember the one about e-flight using the wings mylar as a 'super capacitor'. Wonder if that one will come true too? ;)

Gary
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[Gary Warner]

Well, I bit the bullet, and went ahead to convert it...

Wow! I'd like to see some pictures too.

Gary
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[ZAGNUT]

another thought on how to possibly set up expo and end points:

if your radio is capable enough then slave an auxilary channel to each of the 4 primary channels. plane is controlled by the 4 primary while the training box's servos plug into the 4 slaved aux channels. then play with the mixing parameters including servo direction until you get a 1:1 relationship between the sticks on both TXs.




dave

[Accu157]

I'm going to bring it to the field tomorrow. I've only got throttle, aileron, and elevator, but that's good enough for now. :) I'm going to work on the rudder later tommorrow (today? ;) ) The elevator and throttle are easy to do on any radio, aileron and rudder are a \whole different situation. It really seems to work great! :D BTW, the transmitter face was really bad looking after a few years of use. Scratches, worn out markings, dirty, had peel off lablel material on it too, so I gave it an aftrican mahogany (with red mahogany stain) face lift, with 6 coats of varnish, steel wool, and wax. :D Thanks to my dad for the final four coats. Speaking of facelift, I think my plane could use one as well.

Oh, and my radio is really incapable of anything, it's a generic 4 channel radio only used with one plane. My newer 8 channel is on a different frequency. :(

So what do I call this thing? A slave radio?

[ZAGNUT]

slave driver?

[Accu157]

slave driver?

Hmm, slave seems to be part of the needed name. Keep working on it. ;)

Well, I finished it! :D Works fine too, the only problem is that standard servos have quite a bit of slop in them, so it's definately not a solid feeling radio, but what matters, is that it WORKS. :o If I wanted less slop, I'd have to buy digitals and a high quality geartrain, which for it's purpose, is totally unnecessary. Not enough room to fit the battery inside, so I'll equip it with some D-cells or something like that on the outside. I'll get some pics of it, and maybe video if I can find a freeware *.mov file compressor.

[Gary Warner]

So what do I call this thing? A slave radio?
Stick Wiggler?

Snitch Box?

Show Me Box?