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[Corposant]

After changing the prop and shaft in my Clyde Puffer, I planned a brief speed check in the domestic test facility. Before starting, I connected everything up and switched on the Tx and Rx. Moving the appropriate stick forward produced the expected increase in motor speed. Moving the stick back produced a click from the ESC relay and the expected increase in motor speed. What was not expected was noticing that the motor was still turning in the same direction!

At this stage, I must point out that the ESC was made up from a Maplin's kit c. 1976.

The only explanation I could think of was that the relay was failing to change over (even though it clicked). So... I removed it from the board and it worked perfectly!

As I wasn't interested in reverse for the speed check, I soldered the relay back in, charged the Rx,Tx and 6 volt battery (overnight) and pressed on with the test. The ESC worked perfectly! My little grey cells are not up to explaining this! (Although the Rx battery had obviously been low, it still had enough oomph to drive the steering servo.)



BTW, speed test satisfactory!





Mike

[john s 2]

If the esc has not been used for a while. Its possible that the relay had tarnished contacts which needed a
few operations to clean through. If you look at a quality relay, the contacts are slightly domed. When the
contacts meet a rubbing action should occur this keeps the contacts clean. Just a thought. John.
   

[Corposant]

Hi John

I think you're right, it must be down to the relay. Any failure in the electonic components couldn't possibly result in the motor not changing direction. Although the relay could be heard clicking, perhaps - as you say - contact was not being made.

Thanks for your thought!

Mike

[malcolmfrary]

If the relay went "click" there should have been either reverse or nothing unless the contacts didn't move.  As soon as the contacts move, the "forward" connections are broken.  Resoldering might have given it enough of a scare to start it working properly.

[Corposant]

Malcolm

Sorry I haven't replied sooner to your post - I have been locked out of the forum for a few days (chose the wrong moment to change my e-mail address!).

I had assumed that the clicking noise had come from the contacts but obviously could have come from the armature hitting the coil. As you and John S say, the most likely explanation is contact failure. I like you're soldering suggestion - removing an 8 pin component takes a bit of working round!

Mike