Best posts made by hamel

Get a custom one made. They don't cost all that much, and you can just get the exact size you need to avoid the hassles of either specing them to run in series, or dealing with multiple thermisters and heaters from the control side. I would recommend a thermal switch (manual resettable) that is just above your max temp range incase the SSR fails closed (does happen). Alternatively, you could add a contactor that will trip if a fault occurs (more industrial oriented persons will prefer that method).

I run my pump when the hot end or chamber temp is over 40C. I have a diode at the end of each trigger. One going from the hot end thermostatic output and one going to the chamber thermostatic output, to the relay for the pump. My fans also exhaust heat from my electronics bay, so they run when the system is powered up, with a powered intake to the electronics bay. You could probably set this up without diodes with conditional operators if you are running a compatible firmware version.

I have flow controls on the returns of all of my tools and steppers, and I adjusted the flow by watching the flow rate out of the returns and making sure that they all were flowing around the same rate.

I don't know if cold side temp will affect much in print quality, but I assume that colder is better considering the limitations of watercooling with ambient temps.