oldgearhead wrote:

First of all I haven't used PID for several years. Instead I use BTU's per pound with the final temperature about 435 DF., based on the ambient temperature. When you pick a controller, be sure and get one that has % output function. Then you won't be a slave to PID either, you have a choice of method.

For me communication with the outside world (PC, PLC, SBC, etc) isn't necessary to roast good coffee, and the wires required just get in the way of coffee roasting.

What is more important is a clear view of the coffee states as the roast progresses, and a way to measure the bean expansion.

A 25-30 amp SSR should easily take care of your needs. I also think control of blower speed is just as, or more, important than temperature control. Because it is temperature control! The higher the blower speed the cooler the roast temperature and vice-versa.

But take what I say with a grain of salt, because no one roasts coffee like I do, using an ever-increasing ROR temperature designed roaster that reclaims hot air from the RC. Also the % on time of the heater is a simple calculation based on the ambient temperature.

We may be kindred spirits OGH! The FB roaster I've recently finished does this exact same thing... I think.

I turn my blower on and I turn my heating element on and the only control over the roast is airflow via the blower. My roaster is pretty efficient in reclaiming hot air and recirculating it so the temp is always increasing throughout the roast. I can't (chose not to) cycle the heat source on/off - it just turns on and keeps getting hotter as the air is recirculated. Is that what you're talking about?

oldgearhead wrote:

...ever-increasing ROR temperature ...

allenb wrote:

Avery, great looking popper work and controls! An equipment saving tip I'd like to give to you that saved a few of my builds from going poof is to feed the heater circuit input from the leaving side of the blower switch to ensure it's on prior to firing up the heating element.

Allen