Digital Kiln Conversion

How many hours have you spent watching to see when that little cone will melt and flip the switch on your kiln?  If you have a manual kiln sitter you know what I'm talking about.  With no indicator to tell you what the temperature is or how far the kiln still has to go, you check it every 5 minutes when you should be working on something else.  It's nerve wracking to say the least.

I hope to solve that problem, and a few others, on my kiln by converting it to a digital controller.  In addition to the actual, real-time feedback of the kiln temperature, I'll be able to program the kiln to increase temperature at a desired rate and hold for a designated period of time.  All this hopefully means better, more efficient firing.  Let's get started.

When I began researching this conversion I, of course, went online to see what information or tutorials I could find.  To be honest, I was disappointed with the lack of information on the subject.  Isn't everything supposed to be on the internet by now?   Maybe most people just upgrade their whole kiln.  That wasn't in my budget.  I bought a digital controller made by Olympic that is designed to replace the old kiln sitter.

Here is my lovely kiln before the conversion.  See the little gray box of the kiln sitter? That's what will be replaced. Well, sort of. you'll see.

First, UNPLUG THE KILN.  This step is very important.  You are messing with 220 here!  I forgot to do it until part way through, sheesh!  Don't tell my husband.

Now work can begin in earnest.  Remove the face plate screws of the kiln sitter and pull the plate forward.  You should be able to see the wiring for the kiln sitter.  I don't think mine had ever been opened, that is some very old dust!

At this point you can disconnect the wiring and remove the kiln sitter guts.  Just don't forge the orientation of the wires you are disconnecting.  Label them with tape if you need to.  At this point I realized that in order to remove the kiln sitter post, I would have to take off the entire gray box.  Loosen more screws and the nut at the back of the post and it should all come right off. and you are left with a naked kiln.  Yes, that's me in the reflection, hiding behind the camera.

Now, in order to have a good heat sink, the gray box must be re-attached.  Screw it back onto the kiln without all the kiln sitter parts.  There is a nice little hole for the temperature probe and all of the wiring ready to be connected.

Here's the wiring.  The wires are connected to the new controller in the same orientation as on the old controller.  (bottom right to bottom right, bottom left to bottom left, etc.)

Next, place the temperature probe through the little hole in the kiln brick where the kiln sitter post use to be.  It should stick into the kiln no more than 1".  Stuff the kiln fiber around the probe to secure it in place and seal the hole.  My kit came with plenty of the kiln fiber.  I used some of the left over to seal a few tiny gaps that I had at the corner of the floor and sides of my kiln.  Hopefully you don't have any of those little gaps.  Either way, save your extra fiber.  It could come in handy some time.

Here is the step that took me the most time.  Since my kiln in not an Olympic brand, the mounting bracket holes on the new controller did not line up with the old box.  In addition, I needed some extra space for the length of the temperature probe.  This is what I came up with.  I used some "L" brackets to mount the new control box.  I used the old screws and holes from the face plate of the kiln sitter and attached the "L" brackets there.  Then I used some sheet metal screws to attach the new box to the "L" brackets.  This gave me a secure connection and provided space for the probe.  I think it will also improve the heat sink, which will be better for the controller in the long run.

NOW, you can plug it in and test the controller.  It should read "idle".  If you have control knobs for the elements, they will be turned, permanently to high.  The controller will now be turning them on and off for you.

Note: As my husband pointed out, I need to put some kind of protective something to box out that open space between the two boxes.

Also Note:  I am not an electrical contractor!  Please approach anything with 220 power with extreme caution and call an electrician if you have any questions or misgivings.

I can't wait to give this controller a test run! I'll let you know how it goes.

Happy firing,
Kerri