Motorized Coffee Roaster From Popcorn Maker




Introduction: Motorized Coffee Roaster From Popcorn Maker

I have started my journey in home coffee roasting. One of the most affordable ways to get started in home roasting is with a Whirley Pop popcorn maker. The biggest drawback to this is that it has to be cranked the entire roasting process. This is my solution to that very issue.

My ultimate goal was to keep the original functionality of hand crank, so if I wanted to revert back to the manual version I could in just a couple of minutes.

Enjoy, and dont forget to VOTE!

Step 1: Remove Hand Crank

You will need to remove the hand crank from the Whirley Pop. There is a Allen set screw on the end of the hand crank rod. Back this set screw out a couple of turns so that it slides off of the end of the crank.

Step 2: Modify Motor Shaft

The motor I used is a 12V DC gear motor I purchased a long time ago from Jameco Electronics.

To modify the shaft I connected the motor to a power source and turned it on. I then used a Dremel with a grinding wheel and removed enough material to reduce the shaft size to the proper diameter.

Once the overall diameter was achieved, I then used the end of the grinding wheel to create a flat side.

Take your time during this step. Do not remove too much material at once. (USE SAFETY GEAR)

Here is the link to where I bought the

Step 3: Mount the Motor to the Roaster

In this last step you will fish the wire through the hole in the handle and solder the wires to the terminals on the motor (I connected the wires in reverse to make the auger run counter clockwise, sometimes the beans jamb going clockwise)

I used an old power supply left over from some IKEA LED lights. Installed an inline power switch and thats about it.

The motor free floats and is not mounted to the kettle top. I will keep an eye on it to see if I want to mount it permanently in the future.

This modification does not affect the original mechanism and can be converted back to the hand crank in just a few minutes.

Thanks for taking a look at my project and dont forget to VOTE!



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18 Discussions

A last question. How did you get the digital thermometer probes and wire into the roaster and how did you connect them so they weren't flopping around. What did you connect the probes to?

4 replies

The last last question. The two probe thermometer? I use a indoor outdoor temp thermometer making my yogurt, but it only has one probe (for outside the window) and is limited to around 150F. I generally like the yogurt to mature overnite in the oven, with the lights on, to 120F max. My candy therms will go past 400 F and around to 100 F = 500F, but are so inaccurate as to be useless.

I searched the Grainger's catalog last night and couldn't find one that is affordable for my pension.

I slipped them through the "latched lid" for now.

What I plan on doing is getting 2 springs (maybe 1/8"?) One long enough to go to the bottom of the roaster and one to the center of the chamber. Punch 2 holes in the ("latched lid" Then slide the probe wire through the center of the spring and attach the spring and wire to the lid.

I will update the Instructable once I have made the additions.

I've had a relic 120 VAC laboratory tilt table with speed control in my basement for ages trying to give it away with no luck. I just found a use for the motor and motor control. Thanks. I don't know where to vote, but you've got my vote.

1 reply

Yeah I have a hard time parting with items like that as well. Best of luck! and please come back and share a pics / link to your build!

this is great! You answered a big question I had about the temp of the motor during the roast. For the past two years, I've been in Korea with my family and my wife's electric roaster never worked well on a transformer, so she's used the jiffy pop method for the last 18 months. I've thought about doing the same modification for a while and will finally get to do so very soon. I also added a BBQ thermometer to the lid so she could have an idea of the temp. Not super accurate, but once you understand the readings, results can be repeated. Thanks again!

1 reply

For temperature readings, I use a digital thermometer with 2 probes. I place one probe in the bottom of the kettle where it will be covered by the beans and the other in middle of the kettle making sure its not touching beans or metal. Here is a link to Amazon for the thermometer. I also added a "motor mount" yesterday. Here is a snapshot. I want to make a more permanent motor mount some time, but this will work now now. Cheers!


I wouldn't suggest trying to roast inside, unless you really like the smell of coffee. (I did the first time, not a wise idea)

Just did a roast tonight. Motor did not heat up at all.

@tom, it doesn't reach that high of a temp at the top of the kettle. It is hot, but I have touched it without causing a burn

Thanks man! Just finished it last night. Going to try it out tonight.