RC Tank Warfare community hobby forum

I got myself a Heng long TK-7.1 mfu and radio and wired it up to the gearboxs im using. Question is, does it heed the recoil unit to be connected to hear the main gun sound ? I can get the start up/ engine and machine gun sound to work but not the main gun sound. Hold button B and press A ?? Think this is correct. Looked through old threads but cant find anything similar to my problem.
Any help would be greatly appreciated as im a complete newbie to the tank side of rc.
Thanks.

On the airsoft rigs and I think the recoil systems, there is a micro switch that triggers the (dreaded) track recoil and sound. On the 7.0 and 7.1 the track recoil can be turned off with the transmitter (possibly the 6.0 and 6.1 versions too). You might look in the turret and see if it has that micro switch and is it being contacted as it should.

So yes I think the recoil is needed for the cannon sound.

Recoil unit ? servo recoil?

CN6 trigger switch might be written on the back of the board what the sockets are but you can put a jumper in cn6 and it should give you gun fire sound when activated if no microswitch is in use

Perfect, got it working. Thanks very much. So far i have a bare hull with two gearboxs and the mfu, it would have taken me a long time to work out the microswitch requirement.
Thank again.

john1970 wrote: ↑Wed Oct 01, 2025 12:35 am Recoil unit ? servo recoil?

CN6 trigger switch might be written on the back of the board what the sockets are but you can put a jumper in cn6 and it should give you gun fire sound when activated if no microswitch is in use

I forgot about that. He is exactly right! When I did my M4A1 my first 7.0 version I found a plug in a parts box that fit in the CN6 slot. I simply soldered (or twist or crimp) the wires together and the cannon sound worked.