Wraith, the El Cheapo spinner

[knightrous]

Don't use a servo to trigger the microswitch, if the servo fails or jams, you cannot turn your weapon off (VERY DANGEROUS).
Use a battle switch or a modified ESC to trigger the relay, it's the only safe way.

[Eventorizon]

I would just use an ESC! Conker 1 and Conker 2 both got their solid state relays jammed on at GSL 2012 and 2013. Despite both being capable of 30V & 100A and 50V & 80A respectively both failed repeatedly.

[knightrous]

I would just use an ESC! Conker 1 and Conker 2 both got their solid state relays jammed on at GSL 2012 and 2013. Despite both being capable of 30V & 100A and 50V & 80A respectively both failed repeatedly.

Did you have a flyback diode fitted across the SSR outputs? If not, it's very easy for a large voltage spike to cause them to jam on, I had a similar issue with MBX2, my Melty Brain FW.

[Eventorizon]

Did you have a flyback diode fitted across the SSR outputs? If not, it's very easy for a large voltage spike to cause them to jam on, I had a similar issue with MBX2, my Melty Brain FW.

Yeah, I had the ones they supplied with the relays fitted. After it happened the second time I made sure I was doing it right, but it still kept happening. And at £30 a relay and going through 4 of them... might as well have got a beefy 1 way esc.

[overkill]

Don't use a servo to trigger the microswitch, if the servo fails or jams, you cannot turn your weapon off (VERY DANGEROUS).
Use a battle switch or a modified ESC to trigger the relay, it's the only safe way.

Apart from the servo jamming, its quite possible for the relay contacts to weld closed. I had several spectacular automotive relay failures in my early bots and went up to a massively overrated relay that finally solved the problem. Using a TZ85a esc would make sense and its well overrated for that motor.