Do-It-Yourself Turbo Crazy Coffee Roaster

          Last updated Sunday, 2011-04-15

Overview

Basically the DIY Turbo Crazy Coffee Roaster is a 6 quart West Bend Stir Crazy Popcorn Popper with a portable "Turbo oven" set on top. These ovens are small convenction ovens which sit on top of a bowl and blow hot air. The popcorn popper heating element should be disabled and various simple modifications made to base of the popper. No modifications are needed to the turbo oven except discarding the bowl with which it comes.


Photo #1: Note the model number of the oven is SO-2000. This is the manual, analog model, $55 dollars if the "Motor Top" is purchased as a "replacement part" from: SUNPENTOWN International, Replacement Parts for Ovens



Photo #2: The popcorn popper can be the 6 quart or the 8 quart models, the bases are identical and we only use the base. The models differ only in the size and shape of the bowl. The 6 quart models are cheaper and everywhere, eBay, Amazon, and in many retail brick & mortars. I picked up mine at Target for about $25.




Popcorn Popper Modifications

Disabling the heater

Photo #3: Unpack the popcorn popper and remove the bowl. Use it to hold all your parts. Set the base upright so you can unscrew the stir bar retainer and remove the stir bar. Now, turn the base over and note the cover on the bottom held on by 4 screws. The first photo is what you will find when you remove this cover.


The round thing is the motor which turns the stir bar. It is not secured but simply held in place by the base. The two nuts and studs you see on either side of the motor attaches the base to the heat plate. These nuts are 7mm and should be removed. The contacts you see under the base atttached to the bottom of the heat plate is a thermostat. Remove both clips to the thermostat. Carefully lift the base off the heat/stir plate and reach between and remove the stir post. There is also a thin white teflon washer in there that should be removed.


It is important to disconnect the heating function of the popcorn popper. Some people do not disconnect the heating element, and they experience much shorter roasts than those who do disconnect the heating element. One of the nice things about this roaster is the extended roast times over something like an iRoast. This well separates the first and second cracks. It is your call.


Photo #4: To disable the heating element, disconnect BOTH clips on the thermostat. Carefully lift the base off of the heat/stir plate. Only the black lead off the outlet prongs is joining the base to the heat/stir plate. Carefully rotate the base until you see the posts in Photo #5. The nuts on these posts are also 7mm. Remove the 6" white lead from its post and remove from the unit. Carefully rotate the base back onto the two securing studs. Reconnect the one remaining lead to the thermostat just to keep it from flopping around.




Photo #5:



Photo #6: The removed thermostat lead.



Replacing the drive spindle

The stock drive spindle is plastic and with the heat of roasting will eventually fail. Replace it now and forget about it forever.


Photo #6: The stir motor has a 1/4" square drive which conveniently fits a 1/4" drive socket. Find a 1/4" drive socket which fits inside the drive spindle hole in the base and extends above the surface of the base. I used a Craftsman 7/16" 6 point deep socket. This socket is 2" long and extends 1/2" above the base. I found a bolt, 2 nuts, 2 1" fender washers, and a lock washer. The 7/16" socket is dropped down the center hole in the popper base and rotated to engage the drive motor lug. Then the stir bar assembly is dropped into the socket. Note that the bolt head and lower nut fit into the socket which stabilizes the bolt in the socket. The stir bar may need to be adjusted to ride level and at the proper height. Both the lower fender washer and the 1" copper plumbers cap have been notched to accept the stir bar. Use cooking foil to around the washers and nut to secure the copper cap in place. This cap is not necessary, but gives a cleaner finished look.

On the right in this photo is the black plastic spindle and stir bar retainer cap which were removed earlier.




Chaff ejector and the finished popper base Photo #7: The finished popper base. Note the chaff ejector. This was fabricated from a 42" strip of 1-1/2" aluminum, and 4 small screws and nuts. 42" gives a 6" overlap. Drill the holes with a 5/32" drill, then 10x24 screws will self tap the holes in the soft aluminum. You may not need the nuts. VERY carefully size the diameter of chaff ejector with the placement of the screws. Done properly you will achieve a tight fit against the inside lip of the popper base.




The Finished unit Photo #8: The finished coffee roaster. Simply set the turbo oven on top of the chaff ejector or the base unit if you did not use a chaff ejector, and you have completed the Turbo Crazy Coffee Roaster.




Total Cost - sales tax not included

An iRoast2 will cost you $170-200 and it roasts about 5.5 ounces (I've pushed my original iRoast to 160 grams). The Turbo Crazy will roast about 10 ounces. So, twice the capacity at half the price.
The Turbo Crazy was not my idea. Here are the best links I have found to other Turbo Crazy build sites.