I'm also a firm believer in progress and automatic stuff in business applications. It makes sense. But here I am, learning fundamental stuff about roasting. It a bit like learning to cut wood with a hand saw before picking up an electric one or a cnc machine. Also, beyond flicking a switch on/off or changing the battery, I'm not electronically minded. This roaster has a pid controller for bt and temp set points and tiny little buttons I will not press because my eyesight is noooo gooood.
The guy that sold this thing is a professional roaster. All his sample roasting was done varying heat and keeping airflow constant (on 4). He roasted a sample which I got to keep and no, I didn't like the flavour. That said, I'm happy to try any suggested profiles.
This whole computer/pid thing honestly is like a foreign language to me. If someone is willing to help clear up all the intricacies, I would be willing to learn. From what I can gather, a pid controller is digital. That means a gas flame with pid controller is either flat out or off with no gentle heat cycles. Am I right? Well that would surely have its own characteristics and influence on profiles. If I'm right that is. I could be wrong in which case please ignore my comments.

Oh don't get wrong. I am also a firm believer off learning to walk before you try to run. I was not suggesting you try to PID your new roaster. I was just responding the statement you can't PID a Quest. I've been home roasting for 15 years on air roasters, have a lot of PID experience, and luv the PID on my air roaster. However, if or when I start using a drum roaster, you can bet I would not start off trying to control it with a PID. Automation is something you do "AFTER" you learn the process.

Just because the automation is available, doesn't mean it must be used. The best part of using the thermocouples and software is that it frees you from trying to jot down notes while roasting. Been there, done that, and do not miss it a bit. Things can get by you while concentrating on writing, sorta like texting and driving.

It has been proven that the brain is not wired to "multi-task", regardless of what we may believe.

Automation aside, roasting is not as much art as it is science. having the data more easily and clearly laid out will help one learn to roast, rather than hinder the process.

I get that it's a science just like cooking. I have a fairly scientific mind for things, just not electronics. The roaster give temp readings and if the pid controller could be wired to a computer, well then the temp readings can be mapped at shorter intervals. For now, I'm recording readings at 1 minute intervals, and first crack time etc. Being old means I can look at figures and see trends and RoR without need for graphical representation. My mathematic ability is OK. I just need to get used to temp controls and how much or little to tweek the controls to get the desired effect. I can't see that looking at a computer screen is going to help. From what I have seen of professionals roasting, the controls are not changed that often. It seems more about the different bean varieties and knowledge of the roasting apparatus.

The PID on the 800n doesn't do anything except display the BT and set an alarm function. If you didn't get the owners manual with the machine, I've got it. Of course one could roast with fixed air and variable gas or any combination of the two. It has adjustable drum speed as well.

Coming from a Behmor to the 800n was pretty overwhelming at first, and still occasionally forget to turn on all the switches before lighting the flame. The beauty of the machine is that it's totally adjustable in every aspect, and can "turn on a dime" so to speak.

hankua wrote:The PID on the 800n doesn't do anything except display the BT and set an alarm function. If you didn't get the owners manual with the machine, I've got it. Of course one could roast with fixed air and variable gas or any combination of the two.

I would love to see the owners manual since it was not included. It would be great if you would share some of your techniques. I'm really coming from nowhere with this roaster. I don't see any online group of users with the same roaster. Perhaps we could start a sub-forum within h-b? If it doesn't violate any rules.

BenKeith wrote:'ve never used or even seen a Quest but I'm not sure why someone can't control the roast with a PID. If it's electric heat, an SSR will control the heat, if it's gas heat, guys have developed strategies to modulate a gas valve so they get any heat setting they want, and If it has an AC blower, blower speeds are easily controlled also. Granted, getting the control I have with my air roaster my not be possible, I can set up a profile and hit my desired temp set points within a few seconds, but once familiar with it and what you want to do, programming a profile that does that should not be a problem. Plus, you can always take control back and make little manual tweaks sometimes needed and go back to the PID when things are back like you want. With my air roaster, I load the profile I want and all I have to do is hit load beans to start it and the eject tab to stop the roast at the end, everything between those two points are controlled by the PID, and normally, very accurately at that.

Needless to say, I am a firm believer in the control a PID offers. Like back in the 50's and 60's, people still wanted vehicles with manual transmissions, today, 80% of the drivers on the road wouldn't know what to do with one.

PID, not PID doesn't matter, you don't need a temperature controller like a PID to control a roast. A PID is great for holding a system at a steady state and damping out variances to that state, Roasting is not a steady state process. So a simple on off temperature controller will suffice....but that's all a read herring, because controlling a roast automatically requires a few things.

Controlling power input
Controlling air (if available for control)
Ability to monitor temperatures
Ability to respond to control power input/and or air if required (saved profiles)

PID...neither here nor there in control of roasters....and the complexities are high..if air and power are controllable, you have multiple ways to skin the same cat, and either dump heat, or go faster. In reality a lot of roasters don't fiddle too much with the air settings during the roast. You talked about gas valves, sure you can "modulate one", but unless you change the air (I don't mean the push or pull thru the roaster) as well and control that, you don't really get proper control. Full modulating gas trains are sealed from the outside and have MAS and proportional valves.

And once you have done all this to the fully automated roaster....most sample roasts are done on something smaller, usually with manual control and often a very different heating strategy to the main roaster?? Lastly there is a problem with automation, it's consistent, sorta like Mac Donalds, but there's never any variation that helps you "learn" and often we learn by these "mistakes"

What do they say, a picture is worth a thousand words.
This is PID Control on an air roaster. Until you know how one works, don't say what it can and can't do.
The nice part about it, it will do the next, ever how many roast you want to do, just like this one.
Each temperature changes were within a few seconds of the programmed time, most within two or three seconds
If I want to change anything about any phase of the roast, I control that change almost to the exact degree and second I want to hit that degree.
The first and major thing about a PID is knowing how to set one up. It's not just controlling a steady temp. It's for controlling a process when you know what you're doing. I also have full control over the blower speed and the amount of air I'm pushing through it, not just the heat.

Hi Keith,
Firstly as you stated, you have to know how to set up a pid ( I don't). Secondly, you have to know what parameters to enter. Presumably this relates to a roast profile you deem good enough to repeat, right? So that would be done manually.
So I would repeat what was said earlier that once the method is automated, we stop learning. We are hobbyist roasters out to explore. I think you have convinced me to keep things manual.