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How to Program Your Kiln's Controller to Achieve The following question is from Gretchen A. who writes: Tim's response: I think I can give you a couple of directions to help you find what you’re looking for, but it wouldn't serve you well if I didn’t share one very important piece of advice first... You see, even though your kiln's controller is perfectly capable of firing to specific equivalent cone values, it can only do so when all of its individual components are functioning properly. Just ONE small, defective component can easily limit the whole system so much that it simply can no longer fulfill its programming. For this reason, it easily becomes a possibility where significant damage can occur to firing clay work far before we are even aware that it's happening. This is exactly why I wrote the eBook "Pyrometric Cones… why you should NEVER fire without them!". NOT using cones in each firing (regardless of whether you use a controller or not) is really a big mistake. Those cones are your kiln’s cheapest insurance plan and extremely valuable in their ability to not only reveal the condition of your equipment, but also to give you a backup system so that you always know the status of a firing (especially when the electronics unexpectedly go down). Just remember that even if you don't plan use a full 3-cone witness pack, it will always be the wisest policy to strategically place at least one target witness cone as a backup. Incidentally, this is also why a person should NEVER fire a kiln knowing that they will not be present at the end of its cycle. Oh sure, you might actually get away a number of times, but merely assuming that everything will be OK is about the best way I know to set yourself up for BIG trouble! Therefore, my friend, go ahead and start your kiln while you’re not there if you wish, but ALWAYS be sure to be there by the time it finishes. You can easily do this by delaying its starting time with the controller’s delay feature. All righty then, enough said about that... As far as determining a firing schedule to achieve an equivalent cone value there are two quick methods that you can use. Of course, I realize that this will sound like a shameless plug, but all these things you’re asking about have already be written in detail in my “Smart kilns” eBook available on the "Art Teacher Ceramic Center" web site. My honest intention for even mentioning that here is simply because your question does not have a quick answer... there are just too many peripheral aspects that need to be considered regarding your individual firing situation. The limited scope of this message simply can't address many of those issues, but that eBook covers them ALL. Even so, in order to give you a good direction right away, perhaps one of the coolest ways to get the data that you’re looking for is to go to Orton’s web site and download the free “Cone Calculation Software” they have available there. The file is only about 5MB and downloads pretty fast. This particular software includes 5 different functions for determining many aspects along the lines of what you want to know. It’s a great little tool geared for those who already have a good understanding of heat work mechanics, but would rather not manually do all the math. One thing, though... it can only output information based on what the user ALREADY understands about their firing objectives. Therefore, this tool is not something that I would suggest for someone with limited practical firing experience to jump right into. However, using it with a reasonable understanding of how ceramic materials respond to time and temperature (that is, a good understanding of "heat work"), this software can be quite useful, indeed. On a more simplistic note, you can also acquire the data you seek by using the published cone charts also available from Orton. The charts give equivalent cone values that you can expect to achieve at specific temperature targets. NOTE: It must be emphasized here that simply reaching a particular TEMPERATURE does not necessarily mean that you have achieved a particular level of "HEAT WORK". Just keep in mind that using those published cone charts in order to achieve equivalent cone values is totally based upon maintained a specified rate of heat increase per hour during the LAST 200 degrees or so of the firing. Any deviation from the chart's specified RATE of temperature increase would necessarily cause the final firing target temperature to change as well. Fortunately, the beauty of your controller is that you can program the last segment in your firing schedule to maintain whatever rate you wish. Therefore, in order to achieve a particular equivalent cone value, just create the final segment of your program to specifically cover the last 200 degrees of the firing. Then, simply plug in the temperature rate and end temperature values as suggested by Orton’s chart, and you're good to go! Again, understanding WHY and HOW that actually works is very important and someone who does not have a working understanding of those mechanics could get themselves into trouble pretty fast. Even so, such understanding is fairly easy to acquired and the benefits of taking the time to learn will only help to move you further into more consistent success. You can get Orton’s software and/or cone charts at this web address: When you get there, just look on the far right side of the page. The software is listed under that heading “Quick Download” and the charts are found under the heading “Cone Reference Charts”. As far as the Clayart forum is concerned, you can easily get there by going to the following address. You will have to register with the forum in order to post questions or comments to it, but it’s all free and quite painless. Simply browsing thru their archives requires no registration. NOTE: A really quick way to go straight to where your question is already being discussed in the forum is to simply type key words of your question into a "Google" or "Yahoo" search. Here's the official Clayart search page: Here's where you can get a copy of those eBooks I mentioned right now: I hope this helps a little bit. Stuff like this can get a little involved and it requires a good degree of peripheral information to really do it justice. There’s a lot of good information out there to get, even if you don’t go for my eBook. So, good luck, my friend... I wish you all the best success! Tim
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