Upgraded my Heat Treat oven PID controller

[Drew Riley]

I built my first heat treating oven a little over 13 years ago, and at the time I purchased just about the cheapest and most basic PID/temp controller from Auber Instruments. I think it was about $45 or so, and it was basically just a set it and forget controller. If I recall, I might have replaced it one time over the years when it failed to turn on, but for the most part it was a pretty bullet proof little controller. That said, it didn't really have any extra features, like ramp/soak settings, although I didn't really need that at the time. If I did, I just manually changed settings on the fly, and did what I had to do.
Well, I finally got tired of manually punching buttons up and down to change temps and decided to see what's new in the last 13 years or so. I found the Novus n24k48 and after reading the specs, decided to give it a try. They typically run around $100 to $120 or so, and they have an app called "quicktune" that you can download to a computer, a phone or a tablet. It also has bluetooth connection for uploading your program, or you can also just manually set and select programs, though it's about 100x faster on the app.

Untitled by AR Custom Knives (Andrew Riley), on Flickr

Untitled by AR Custom Knives (Andrew Riley), on Flickr

Untitled by AR Custom Knives (Andrew Riley), on Flickr

First impressions, this thing is surprisingly smaller than any other PID I've used. The face/opening size is standard, so I didn't have to modify anything there. Wiring seems to be pretty standard as well. It has up to 5VDC pulse for SSRs, so I was able to eliminate a separate power supply I previously had to use, and it also has up to a 3V relay for things like alarm settings and what not. You can also expand the base unit with other modules as needed if you want to add wifi, modbus or other alarms and such. Since I'm still after a relatively basic setup, I didn't need anything extra and it was a simple swap out with my old one.

As for the programming and the app, it's pretty basic and straightforward, and dare I say, unimpressive (but functional). There's a little bit of a learning curve, but it's really not too bad.
It'd be nice if you could name programs rather than just "program 1, 2, 3, etc...", but it's not a big deal to have a list next to the oven that says what steel each program is setup for once you've set them up.

So all said, it's not a TAP controller by any means, but for $100, it's a pretty big bang for the buck in my opinion, and about 1/6th the price of something like a touch screen controller. All in all, I think it's an option worth considering if you want ramp/soak programmability in a very small package that's relatively easy to set up, and if you already have an oven with a standard sized PID, it's about a 5 minute swap out.

Anyone else using one?

 

[WoodenMonkey]

Hi! I just converted a small pottery kiln to a HT oven, using the most basic inkbird PID just to see if it would even work. It works really great and now I want to upgrade a programmable PID. This is the one I’ve been thinking about getting but haven’t been able to find much in the way of reviews. Thanks for posting about it! I think I’m going to go ahead and order one and get some A2 and maybe some AEB-L knives going!

 

[Ken H>]

That's a slick PID with lots of features for $100 or so. I didn't download the manual, so a question: Can you program an annealing cycle where the temp drops a set amount per hour? So the set point drops by... say 50°F each hour?

 

[timgunn1962]

Looks like it. Settings are segment start temperature, segment finish temperature and time between the 2. Say 1500 degF, 500 degF and 10 hours for 100 degF/hr ramp-down. It's how every industrial controller I've ever used does it.

I've never used a dedicated kiln controller, but I gather they need start temperature, finish temperature and ramp-rate: 1500 degF, 500 degF and 100 degF/hrs for a 10-hour ramp-down. Same result, slightly different approach.

 

[Drew Riley]

That's a slick PID with lots of features for $100 or so. I didn't download the manual, so a question: Can you program an annealing cycle where the temp drops a set amount per hour? So the set point drops by... say 50°F each hour?

Sorry Ken, I missed your question until now. To answer your question, you can set a ramping schedule in any direction, so you can program it to drop so many degrees per hour.
Basically, if I'm remembering correctly, you set "segments" and "durations", so it's not so much you can select an overall time frame and start to end temperature, but you'd program segment 1 as your starting temp, and set duration 1 hour, program segment 2 50 degrees less, set duration 1 hour, program segment 3 50 less, set 1 hour, etc....
So it's a little more manually involved, if that makes sense, but once you write the program, it can be stored and referenced later.

Here's a video showing a little bit of the programming process, it's not the best, but you'll get the idea.

 

[Judcargile]

That is a sweet upgrade!

 

[Way-Barney]

PID control.

I Once fitted a PID control to my homebrew fridge to maintain a given temperature as the fermentation process produces heat.
What has that got to do with knives?
I found that trying to reduce temperature is more difficult and expensive than heating things up. The Insulation capability of the oven will be a big factor, if the oven doesn't drop of its own accord to the required set point then you will need some device to accelerate the cooling to the required set temperature and then heat it up again to maintain the set point.
If the insulation of the oven is not very good and it drops ok on its own, Bingo, you are in business.