PID'd S1?

[Endo]

With over 3000 S1s out there....has anyone tried modding one with a PID yet?

I don't think it would add much since it's already so stable. But after installing one on my simple Silvia, I'd be curious to see how it's done on a more sophisticated machine like the S1.

The biggest benefit for me would be to allow me to tweak the steam boiler pressure.

[Richard]

The biggest benefit [of PID] for me would be to allow me to tweak the steam boiler pressure.

I have not tried that sort of modification. But I personally find temperature control on a smallish steam boiler less desirable than pressure control. Why? Highly accurate temperature is unnecessary for steam production, and the reaction time of pressure control is significantly faster; especially with small boilers and reasonably high-wattage heaters, the extra seconds of power-on translate into longer-lived steam. I would use pressure control, whether it be an analog pressurestat or a pressure transducer on an electronic controller.

For simplicity and lower cost, the analog pressurestat would be preferable. For ease of adjustment, one of your criteria, a pressure transducer would be preferable.

[JohnB]

Since the Vivaldi's electronic temp controls are tied into the circuit board I wouldn't consider it a good candidate for a PID conversion. Kee's used a PID to control the steam boiler on the early Speedsters but found that level of temp control unnecessary. Now he uses an electronic controller that looks just like a PID but isn't as sophisticated. It's very easy to raise or lower temp/pressure & I certainly wouldn't trade it for a noisey, failure prone pressurestat. With the fill inlet restricted with an inline gicleur the boiler pressure never drops more then .2-.3 bar even after drawing 4 cups of hot water or during a long steaming session. Something like this might work on the S1V2 if they beefed up the pump motor to withstand the longer/slower refill times.