More Pictorial Schematic for Filastruder

Looks good.  One possible change would be to wire the system so that fan/motor cannot turn on without having the heater switch turned on (series instead of parallel).  The purpose would be to prevent cold extrusion.

Also, the fan is supposed to turn on with the motor, not the heater.

Also, the motor terminal with the red dot is ground.

Your labels for variants B and C are reversed.
There's no center-off position on those switches.

There's no need for a second relay, the internal relay is rated for 1M cycles - that's about 10,000 hours of runtime, enough for 500kg of filament!

By labels I meant headings, but I looked at it too quickly - you are correct, I was wrong.

Also, you are correct about the switches - I was away from them and thinking about an earlier batch. They are definitely center-off.

Again, my apologies. I think maybe my brain needs a vacation - I'm losing my mind here!

I'm not sure about galvanic isolation, though I could find out if you'd like.

I'll let you know as soon as I know!

I wired my machine according to the variant C schematic. When I power the circuit the PID turns on and I configure a target temperature. The nozzle heats up, and there is the red current temperature setting rises.

The motor and fan never seem to turn on, I'm not sure if this is a function of the PID (controlling the ALARM switch) a problem with the wiring or some configuration with the PID unit.

The PID makes a clicking sound and the OUT1 LED turns on and off (toggling power to the heating element, I guess?). No other LEDs turn on.

Has anyone else seen this? Any idea what I'm missing?

Thanks, that did it. You need to hold down the set button until "AL1" is displayed, then you can set a temp to control the alarm switch.

There are instructions with the PID, but the English is fairly broken so its a bit of a challenge to figure out.

Add Minimum PID Settings

Hi Tim,

If I knew on which pins of Sestos PID "alarm" is,
I could complete the schematics  for these variants

Yup, I see what you mean.

Operation Procedures:
1/ Press SET key 2 second into the function mode, after return to the operation mode. If no any change
after 10 second automatic return.
2/ For temperature setting, press the UP or Down key change the value, after 10 second operate the new
setting.
3/ First operate the Auto adjustment, press AT key 2 second, SV display blink AT, finally into PID control
mode. Press the AT key 2 second to abandon Auto adjustment.
4/ If successful the first Auto adjustment, can not use AT key for Auto adjustment again. It need change
function setting Ctrl to 2 to operated again.
5/Auto adjustment needs from few second to few hour.
Suggestions:
1/ If use SSR or SCR for control part, setting control period prefer 4 second or shorter.
2/ If use relay for control part, setting control period prefer 20 second or longer for extend the relay life.

"the English is fairly broken" is an under statement.

But I guess others have gotten it to work so hopefully I'll manage.

Ralph