Mtronik speed controllers with separate BEC

I was puzzled with my twin propped U Class (ORP Dzik). One motor kept on shutting down after a few minutes.

On investigation, I realised that I had stupidly forgotten to do the necessary modification to one of the ESCs. You need to do this when you use them with a separate BEC.

You need to remember to cut the red wire (AAAgh not the blue one - BOOM! (Sorry!) on the lead to the receiver.

And then it is best to cut off the switch and solder both leads together.

Just a further observation on this.

I've found the same problem running a single Mtronik ESC with the internal BEC on the Russian Nordenfelt. The speed controller shuts down after several minutes - needing a rescue (Thanks Dave J!)

Running it flat out in a tank produced the same result. It seems that the ESC gets hot and shuts off.

I conclude that the BEC in the Mtronik is not really "man enough" for running several servos and with a 12 volt supply.

Replacing it with trusty Microgyros one (even though that was the one that got wet in swimming pool for the BBC filming) - no problem in the tank.

Presumably (as others have said) a more generously specified BEC on the Microgyros.

I will try it in the Barrow pond on Sunday.

David

Well the Microgyros one did the trick at the Barrow pond yesterday. The Russian Nordenfelt  zoomed around for 20 minutes without any overheating problems.

So the current state of play seems to be:

- Using the Mtronik BEC you may have overheating problems on 12v. Microgyros seems much better.
(I have put a separate BEC based on the LM2940 linear chip (as per Nigel's post of some time ago) in the Type XXI and this seems to work nicely, without the interference problems that I used to get when using the switched mode BEC. So more efficiency can give more interference!)

David