Just finished my PID. Mypin TA4-SSR w/ 40amp SSR. Lee Pro 4 - 20
Did some minor testing two days ago. Running auto tune several times and I noticed;
Initially temps will overshoot/undershoot; 30-40;12-15. After several auto tunes, overshoot/undershoot was about 12-15; 2-5. Once it settles in it appears to be solid.
Now, the main issue was I cross checked temp with a tru-temp dial thermometer and a electronic thermometers. Dial thermometer was 40 or so cooler; Electronic was 20 or so cooler. I thought, well, I’ll just watch how the boolits come out and adjust.
So the next day during ‘live casting’ I set to 725 and started it up. Settled in at setpoint. Had mold on hot plate, and began pouring lead. I never looked back! Temp stayed at setpoint within 2 degrees or closer! Only sway in temp was when ‘cold’ lead was added in, and it didn’t take long to recover.
Thermometers were re-checked. Dial has the nut behind the dial and I hand tightened; it was within 10 degrees; Electronic was nearly identical; a heat gun on the pot side was spot on. Oh well, I guess I’ll believe the PID!
Takeaways;
Initially, run auto tune as many times as it takes. If it keeps overshooting/undershooting, let things cool and run again. I ran it 3-4 times before I was satisfied.
Believe the temp the PID says.
Record settings - Once done, record all settings, just in case. You can re-input if need be.
Initial overshoot is not a bad thing as long as it ‘settles in’ and holds.
Trust your judgement on temp - How the boolits come out. Adjust temp accordingly.
Find the right temp for you. 725 matches my cadence. Once after adding cold lead I began pouring at 712. Lead was not totally ‘set’ when I cut the sprue. Waited for 725 and all was fine.
Read the manual that comes with the PID. They are all a bit different, even older/newer same models.
Hope I’m on the right path and it helps others a bit to make a decision on adding a PID. If you have other issues, or see any with my operation, please don’t hesitate to ‘steer’ me right! I’m still new!