Air Popcorn Popper Roast Profiles - Page 3

Discuss roast levels and profiles for espresso, equipment for roasting coffee.

#21: Post by minus1psi »

mpdeem wrote: I am not as familiar with the Popcorn you know what the watts/power is?
I am pretty sure there were different models. As I understand it, mine is an early model. It says 1400 watts on the back. I think later models were more like 1250w.


#22: Post by minus1psi »

mpdeem wrote:...If anyone is running Artisan or roast tracking software in other ways tracking their roast profiles - I would love to hear from you. Feel free to post roast profiles and notes. Same applies to PIDs and other modifications - please feel free to share. Please include the type of poppper you use as even among popppers there are many variations.
I am running Artisan with a Wearever™ Popcorn Pumper plus a short glass chimney. To measure the temperature I place the popper directly beneath an IR sensor from Phidget. Issues and struggles with this set-up are detailed in this thread. The height of the IR sensor in the drawing is not correct anymore. I think it is closer.

Milligan wrote:A full blown popper build would be fun. I fear I'd end up with $400 worth of phidgets, thermocouples, PIDs, and misc electronics hanging off of a $20 popper :mrgreen:

I'm interested to see graphs and what folks do to these poppers to make them more roast friendly.
Between the $100 spent on the voltage regulator, $70+shipping spent on the IR sensor, two glass chimneys, $100 on (currently unused) thermocouple phidgetry, $10 on a rechargeable fan, several more bucks on miscellaneous hardware to mount the IR sensor, and $25 spent on a back-up popper from ebay I have to say that your fear is well-founded. The current Popcorn Pumper was a gift from a friend who moved onto a Behmor several years ago. On the plus side by skipping the purchase of the thermocouple phidgetry and knowing what didn't work well earlier I could probably recreate this set-up for around $200. There may be less expensive *and more capable* IR sensors available if you are handy with programming and electronics. On the flip side I could potentially convince myself to spend more on fancier controls such as an Artisan driven servo motor to control the voltage regulator (hoping to increase repeatability).

Here is a recent graph. I think Artisan was set to sample every two seconds. By the way the temperature on the IR sensor is not accurate due to the hardware being in the heat blast of the popper. The IR sensor is cooled down with a couple of fans and the readings seem pretty consistent but definitely not accurate.

Supporter ♡

#23: Post by buckersss »

Ty for sharing. If you got a ~2kva variac you can at least use this with other roasters, so not exactly fair think of it as a sunk cost specific to that setup.

Team HB

#24: Post by ira »

I'm not sure what to do with the info but I think if you have 3 probes, one before, one in and one past the beans you can figure out both bean temperature and the energy currently being transferred to the beans. I added the ability to plot that difference to RT for someone who had no way to get bean temperature, but I have no recollection if it turned out to be useful. Before and after are the two temperatures the Ikawa Pro uses and I wish they would display something on the graph based on that difference.


#25: Post by Milligan »

Ira, exactly what I was going to say. Two TCs for intake (heated intake air) and exhaust (air exiting after heat absorbed by beans) is the way most commercial machines do it. IR seems like it would be noisy as beans go in and out of its sensor range while 3mm TCs would provide a steadier reading due to the instrument itself having its own mass. Intake temp also allows for finer tuning of the incoming air energy instead of assuming voltage/knob adjustments will give the same heat energy day-to-day. Kind of the same concept of damper position vs actual air pressure reading.

I'm enjoying these DIY builds quite a bit. Thanks for sharing!

Supporter ♡

#26: Post by pcofftenyo »

buckersss wrote:If you run the popper attached to a variac you should be able to do some tuning and achieve different heat levels.

IE drop voltage to ~110 and slowly rise up to ~120. Watch for temperature change (without beans) before moving to next dial notch. Move dial up a notch and then drop voltage down again and repeat. When temps are charted you should be able to identify the redundant, or missing, points and adjust the voltage window as required.
My machine was born with separate temp and fan rheostats. I was pointing out that the temp dial doesn't provide the fine level control one would hope for. I wouldn't have know this without the monitoring device.

Without some level of heat control as described and instructed by buckersss and others, I'm pretty confident that some form of temp manipulation is a minimum threshold for decent results.

Team HB

#27: Post by ira »

I think the problem with the temp controls is the people who design then are commonly not roasters. They should probably only adjust some much smaller range like between 70 and 100% with a separate switch for cooling but they seem to think a linear range of 0-100 is necessary. On my computer controlled Behmor, I found that I only adjusted the heat over a pretty small range otherwise I got wild temperature swings, I assume an air popper would be the same. I don't know the appropriate range on your popper, the SM one I assume, but you could probably severely limit it and make the device a lot more fun to use.


#28: Post by Smplif8 »

I built one a few years ago using a West Bend popper with DIY arduino based PID control, I borrowed and modified someone's PID code for a kiln control that has the ability to set the independent temperature increase rate in segment, soak time can also be set per segment. The fan speed can be controlled manually. Graph with artisan is also possible, though a little tricky.

With an added chimney, maximum capacity my roaster is around 190 gram per batch, but I usually do 150 gram batch.

The thing is, I can't taste any note from any coffee, but I know my coffee is smooth. I mainly make latte using an old Expobar Brewtus machine, with a Sette 270 grinder.

Here is a picture of my roaster

mpdeem (original poster)
Team HB

#29: Post by mpdeem (original poster) »

randytsuch wrote:Not sure about the watts. I remember way back when I was building this, I found claims that the original Pumper and the well regarded original Poppery shared the same guts. I believed it and got a Pumper since they were easier to get, and cheaper. It is build solidly, and I've used it for many roasts.
I think you are correct....seem to recall folks on both Sweet Maria's old forum & the Home Roast forum (when it was still very active) were using Pumpers in place of the Poppery for the same reasons you mention here. I might keep that in mind next time I need to replace my Poppery the prices have gone way up on ebay.

The thermostat is disabled and the heat & fan switch seperated on my Poppery. Interesting that the same modifcations can be made on the Pumper. I wonder if it is literally the same internal schematic being used for both brands.

mpdeem (original poster)
Team HB

#30: Post by mpdeem (original poster) »

minus1psi wrote:I am running Artisan with a Wearever™ Popcorn Pumper plus a short glass chimney. To measure the temperature I place the popper directly beneath an IR sensor from Phidget. Issues and struggles with this set-up are detailed in this thread. The height of the IR sensor in the drawing is not correct anymore. I think it is closer.
Thank you so much for posting your roaster schematic and sample profiles. The red variac looks suspcously like the one I purchased (from Amazon) therefore I have to ask have you had issues blowing circuits while using it while roasting? I never used mine so my husband used it for a project -can't remembr what- but he blew two circuits before deciding to put it on a separate breaker.

Looking at your roast profile in the context of location of and issues with the Phidget IR sensor I am curious temperature variation between the sensor's location (over chimney) versus roast chamber temp. In the other thread you mention the IR sensor becoming less accurate during the roast and this got me wondering if perhaps this is an issue we should all be considering.

I have a cooking thermometer placed in the roast chamber slightly above the heat vents. The thermometer is mounted from the side (snugly placed through a drilled hole. No pictures as I can't get my cell phone to download pix to my computer at the moment). I have always assumed that my thermometer is farily accurate in that while it may not accurate as far as exact bean mass temp - it should give a decent picture of the temperature modulation so to speak. For example the bean mass temp may be cooler than what the probe reads but the data is still useful in that one still chart the heat modulation (rise rate and so forth) during the roast. After reading your post and thread, I am wondering if what I think is the heat rise rate of the roast -is instead-merely the rate at which the temperature probe is being heated and cooling. Hope this makes sense.

Another issue that comes to mind is probe placement. If I understand correctly your probe is above the top of a mounted chimney -which would explain to me- the lower roast temperatures of your profiles versus what my chamber mounted probe reveals (never mind differences in probe types-styles). Another factor is that my roast chamber is uncovered -no chimney or plastic popper hood. I like to better observe the beans during the roast...nothing like looking into the blast furnace during the roast ;)

So I wonder if it would be helpful if we all endeavor to follow your wonderful example -and Smplif8's as well - and post photos and/or schematics-layouts of our popper roasters. I will see if I can get photos downloaded and posted. I suspect that temperature probe placement never mind type -will probably account for a tremendous varation in roasting profiles and approaches among us.

Thanks again for such detailed post and including the other thread.

Speaking of the other thread titled BT RoR guidance for popcorn poppers and small fluid bed light that there is some pertinant information there - how does everyone feel about having this separate thread dedicated to poppers only? I am somewhat tempted to suggest merging this into the other one..but then I am reminded of the tremendous differences between poppers and other fluid bed type roasters. Just having a fixed non rotating chamber alone -never mind gas powered versus fan driven hot air I think merits keeping this thread separate and devoted to poppers. What do the rest of you think? No matter what is decided, I hope that folks of all roaster types continue to read and share as the spirit moves them :)