When To Turn On AutoTuning

[fc60]

Greetings,

Here is my process.

I have a 20# SAECO Utility Pot. (The open top model with no Temperature Control.)

After each casting session, I pour out the remaining alloy into ingots then, after the pot cools, I clean it for the next session.

A new session begins with placing ingots in the pot and applying power until the metal is all liquid.

Once liquid, I insert my K Thermocouple that is attached to the PID temperature control box.

I decide I want to cast at 730F. I then set the Temperature Controller to 730F.

At what point do I activate the AutoTune function? When the metal is below 730F? Above? Or, does it matter?

Cheers,

Dave

[HATCH]

This is what I recommend.
If your pot is empty of lead then mount the probe and melt lead.
Let the pot cool back down to ambient.
Once at ambient turn on the PID and run auto tune.
Let it learn from room temp.

Alternatively you can run auto tune anytime just make sure the pot is full of lead when you do it.

[rsrocket1]

With most PID's, autotune measures the temperature vs time as it reaches its setpoint and adjusts the pulsed of power based on how quickly or how slowly the temperature reaches the set point. Usually, it's full on at low temperature until it gets close, then it starts pulsing power so as to not overshoot too quickly. If it rises slower than the first guess, the pulses are lengthened to speed up the heating process so it doesn't matter if you turn the PID on too soon. It will probably be full on at lower temperatures anyway.