So I just received a Quest M3 for Xmas, and so far I'm in love with it. However, I'm also a huge lover of data logging and to some degree advanced control. With that in mind, I'd like to investigate what hardware I would need to put together a PID controller for this roaster. I already have a TC4 on order, and I'm waiting on probes from Eric S. So my next step is to look into the parts for the PID controller.

I've reached out to a few people on here, but most of those people haven't been on the forum in years and I have low hopes of them getting back to me.

Thank you in advance!!

Dustin

Dustin,

I will put you in touch with the guy who bought my Quest, as he plans to PID his.

Checkout "homeroasters.org" they have a section on dataloggers and controllers.

robmatic wrote:Dustin,

I will put you in touch with the guy who bought my Quest, as he plans to PID his.

*waves*

Hi!

I fitted the Quest M3 with three K types (BT, ET and MET) with erics superb adapters, and hooked it up to a TC4C. Gutted the Quest, and replaced with SSRs (one zero crossing and one Phase). Added a Murata power meter so I can see power into the heater.

Used the TC4C with the display board, but hooked the Interrupt line as well. Use two potentiometers to set either PID SP and Fan or %power and fan.

And lastly, have it hooked up to Artisan.

. . . and I'm waiting on probes from Eric S.

And I am still waiting on Omega to ship - they are tardy.

I am NOT a roaster so take my comments with that in mind. I respectfully suggest you put this PID business on the middle burner and get accustomed to the Quest M3 as is. Keep MET at 500F or slightly lower and have a good time.

Probably a good suggestion. I abandoned my own PID plans. Not sure the Quest would be responsive enough... I've heard that PID can cause over corrections back and forth.

+1 EricS's comments. I have an unmodified Quest M3 mk-II. Originally, I thought I'd PID it, automate everything... As a first step, I put in EricS's MET and BT probes, bought a Mastech digital thermometer and set up the lot on Artisan, 'just to get used to it'. I never got past this point. Watching BT on Artisan and riding the controls works fine. My desire to automate vaporised. I still think automating would make a neat project, but I doubt I'd gain anything in the cup. Also, I roast a pound or two every week to ten days, so I don't need the automation as a production tool.

The whole point of PID control is repeatability. As others have suggested, you need to learn your roaster and the only way to do this is manually. If you a want to experiment with many different profiles and perform on-the-fly adjustments, then stick with manual control; its more "playful".

That said, graduating to PID control can be very cool, if you are so inclined. I PID controlled my North TJ-067 with a proportional valve, and I'm never going back. With PID control, you basically design your roasts ahead of time and then test them out. Experimentation is more methodical and planned, and most importantly "repeatable", which meshes well with my engineering background. Tests are not valuable unless they are repeatable, and PID control goes a long way in this regard, which I feel one is one of the unsung reasons to advocate automation.

And while I've always advocated the Huky, the one thing the Quest clearly has over it, is the relative ease of PID-controlling it. If I had one, I'd be all over it.

Yeah, I'm gonna PID mine most likely, probably hitting the MET since (unless I'm mistaken) that is going to be the most responsive point of feedback.

Still need to learn this roaster that I've had for a couple of days so far. Need a new MET probe, I think - the used one that came with it is acting like it's got a bad connection or bad insulation inside the sleeving. The temps jump all over as I handle the cable.

At least the BT probe is stable.

PID will get repeatability and automation, but won't make it possible to do curve fitting of the bean temp.

First, though, I'm gonna roast for a while. Been doing air roasting so long, this is vastly different.