Small Heat Treat Oven

[Boats69]

Boats69---Best answer---I don't know!!---Brian

😂

then likely not, it is covered in that instruction sheet - it will make a huge difference!

[Boats69]

Brian, it should be as simple as setting item 10 (At) to on and then leave it in peace until the tuning is done. I do suggest you heat up the furnace before starting the autotune as the dynamics of the system is quite different at room vs operating temp.

[Tom S]

Good stuff Brian. As Boats69 suggested I'd run that Autotune before adjusting anything else and see how tightly it operates after that.

[brian Rupnow]

I didn't do any more messing around with the controller today. I still have to learn more about it and I've seen that I can get the oven to go to 1100 degrees F and hold it there, which was my biggest question. This oven had the poorest hinge plates on it that I have ever seen. They are only .025" thick material and were bent all to heck. I whittled out some new hinge plates this afternoon from 3/16" aluminum and tomorrow I will concentrate on getting the "door" to fit better and install the new hinge plates.

[Jon Heron]

Once you run the autotune and it is running in PID mode it will go on and off constantly to maintain the exact temperature you set it to.
If it shut off at 1100 and comes back on at 1000 or whatever, than it is just running as a thermostat, not as a PID.
The auto-tune just programs the PID controller to know how fast your oven heats and cools, it uses this to maintain a constant temperature without any significant swings in temp.
When you autotune it could take an hour or so heating up and cooling down till it figures out the dynamics of your oven, I suspect it will be fairly quick with that little oven though.
Good luck!
Jon

[DrMike]

If it were my oven that was heating to 1100°F, I would NOT make the door hinges out of aluminum.
Yes, I know aluminum melts at 1200°F or so, and the hinges are on the outside, away from the heat.
Still, I'd much rather use the cheapest steel I could find, melting around 2500°F. Just sayin'.

But it's not my oven, not my oven door, not my hinges, etc.

[eKretz]

The hinges will be fine. When the door is open, that heat will be going straight up. Being that much hotter than ambient the air will rise like a beach ball from the water. The door should never be open for more than a few seconds either; just long enough for something to go in or out. The hinges are also at the bottom and outside the span of the door width. I doubt that the hinges will ever get much hotter than a bit over ambient temp.

Edit: you can see just looking at the old hinge straps that they don't get very warm. No paint bubbling, nor any steel discoloration.

[brian Rupnow]

This morning I installed the new hinge plates on the oven. The door fits much better with no gaps now. I managed to turn on the Auto-tune function and with the temperature set at 1110 degrees the oven shuts off at 1112 and turns back on at 1108. I'm very happy with that.---and for now, that is all the programming I need. in future I may want to do other things, which may mean that I have to learn more functions, but for now, I'm fine. This essentially ends my work on the oven. Thanks so much for the help you fellows gave me. I would have been lost without some guidance from forum members.---Brian Rupnow

[Boats69]

I call it a win 😎

[Tom S]

Nice work Brian. Glad to hear it's up and running.

[JustJim]

Looks nice and welcome to the forum!

What did you wind up using for the gasket around the door?

I just used the fiberglass cord door seal for a wood stove, I believe it was a Rutland brand I got through Mendards. So far it's holding up OK.