Kiln with digital controller overfiring!

[Bill Kielb]

2 hours ago, kayleyvdb said:

Fingers crossed! The software should be up to date because I ordered it a little over a month ago. Thanks again for all your help!

I am sure you will get it resolved with a logical step by step approach. Nice work, let us know. One observation I should have made and asked earlier (apology in advance for not looking at this closer):  your graph that shows 8.40 hours also shows what appears as excessive overshoot and undershoot. You might want to send this picture to SDS it often is a result of the controller not adapting to the properties of the kiln. (How fast it can heat and how fast it cools during the firing) The parameters that establish this are components of a PID control (proportional, Integral, Derivative) that most electronic controls have used for many years.

Anyway, I would send them this graph, often there are simple parameters that can be adjusted to smooth this out. This control may be smart enough to self learn so If it was using the old anticipated leaky characteristics When the lid was open, it may improve with each firing as it learns the new thermodynamics of the kiln.

If the graph continues to jump above and below setpoint after the next few firings I would send them the graph. They may give you a  Simple program point to change the relay timing or other parameter.

[kayleyvdb]

On 8/24/2020 at 8:24 PM, Bill Kielb said:

I am sure you will get it resolved with a logical step by step approach. Nice work, let us know.

Thanks so much for that insight! I’ll look into it and contact SDS. 

It looks like the 50 degree offset did the trick for the glaze fire! I’m running a cone 06 test today to see if it’s consistent. 

[kayleyvdb]

Results are in ... the cone 06 is underfired with the 50 degree thermocouple offset. I didn’t have cones 07 and 05 for the test but here’s where the cone 06 witness cone ended up. 

[neilestrick]

You can either add a hold at the end, maybe 10-15 minutes, or do a cone offset (I'm assuming your controller has that option?). Personally I'd just do the hold. Also, if you're making your pots with the same brown clay as your cone packs, I'd bisque to 04 to make sure you get good burnout.