Warning vehicle REVERSING! or not?

[Wavemeter]

Hello everyone
I have made some successful restorations but some channels on a few transmitters are reversed. I’m ready to fly on several including this Skyleader and ‘MRC’
Is there a simple method to achieve servo reversing ?

[Martin]

Normally you can just swap the GND and +ve wires that go to the relevant pot(s) in the transmitter for the stick you wish to reverse. If you're using one of Phil's encoders, there is probably an even easier way of reversing channels - what encoder are you using?

The way we used to do it years ago before transmitters had reverse switches was to fit a reverse direction servo in the model - you can swap a servo over to reverse operation by swapping the GND and +ve wires on both the servo motor and the servo feedback pot. People who didn't like wielding a soldering iron used to fit the servo upside-down if there was room or alter the linkages to the control to mechanically reverse the direction.

[Wavemeter]

Thank you.

Tried swapping wires on the tx pots but must have had incorrect combination - just caused full travel one way or another depending on wire position . Will have another crack at it. Yes familiar with modifying servo or even other way up but want to achieve compatibility across models . All encoders are the originals

[Martin]

Most pots have the 'wiper' pin in the centre and the two outer pins are the two ends of the pot track. It's the two track ends that need to be swapped. If you trace back the wires from all the pots, most transmitters will have all the 'track end' wires connected together (a bunch of GNDS and a bunch of +VEs) - but then the wiper outputs will each go to one 'stage' of the encoder.

How do the trimmers work on those transmitters? If they're mechanical then no worries but if they're separate trimmer pots you may need to reverse those track end wires too - post a sketch or photo if you're unsure and someone here will be able to advise.

[Phil_G]

Half-shot encoders rarely had the pots set midway at neutral stick, so reversing the connections will introduce a huge offset, and you would need to rotate the pot shaft wrt the stick to correct the offset.
If it was me, I'd leave the transmitter alone - thats how they were and if you modify it for one model it will be wrong for another. So I'd use the methods we used in 'Skyleader times'. Firstly I'd try shuffling servo installation to use the opposite end of the output arm, or use a reverse servo (Hitec & Futaba move in opposite directions for a given signal) or as a last resort if all that failed, on-board servo reversers.
Cheers
Phil

[Wavemeter]

Thank you Martin & Phil. Martin fully understood and I thought that would be the way to do it - but Phil I think you are dead right huge offset and it all in a muddle . Will work on the idea of electronic plug in reverser if I can find one- that then could easily be transferred across models. I have a feeling I saw some on Hobbyking site

[Flynn]

Thank you.

Tried swapping wires on the tx pots but must have had incorrect combination - just caused full travel one way or another depending on wire position . Will have another crack at it. Yes familiar with modifying servo or even other way up but want to achieve compatibility across models . All encoders are the originals

I think you might have missed in Martins post -

you can swap a servo over to reverse operation by swapping the GND and +ve wires on both the servo motor and the servo feedback pot.


You have to do both or else you will end up with the problem you had... anyhow, you are probably sorted now...

[Mike_K]

Jonathan

If you were using the original SRC1 servo's (which I wouldn't necessarily recommend as the arms could have gone brittle as I found out the hard way), they had a black dot on them for reverse action and no dot for normal. Futaba did something similar at the time with red and black labels on their Futaba FD-16M servo's .

But when I'm flying my 35MHz Skyleader TSX with original Rx and modern servo's, I just use a cheap servo reverser from Hobbyking (about £2 each) on any servo that goes the wrong way. Saves messing about with servo motors and pots, especially as the motors and pots on modern servo's are not so easy to swap as on older servo's like SCR1's.

You could make your own servo reverser, but the Turnigy ones are cheaper and more compact than you could make.

Mike