How to build a Stir Crazy/Turbo Oven (SC/TO) coffee roaster is very well documented on the internet and can be found through google searches and YouTube searches. I'm only providing a way to modify this type of roaster to faciliate larger batches with even roasts.

IMO: This is the best modification you can do for a few bucks to eliminate the weak motor of a homemade SC/TO coffee roaster and increase your roast size.

This modification will make your roasts more even and allow larger roasts up to one pound and more.

I normally roast 1 lb 2 oz at a time (~3 cups) and can easily do 5 lbs/hour without hurting myself. If you want to do smaller roasts, I suggest you play with the stir arms to get good agitation of the beans tumbling them over the stir arms without pushing the beans too much. I put small roll pin sleeves over my stir arms to get it right for my roast size.

Use the shaft modification method below when using the orginal fiber shaft.
Otherwise use the more recent modification of the stir shaft detailed farther down this page.

Coupler:   Link to 7mm to 8mm Coupler on eBay

Motor:   Link to motor on eBay

In order to increase the heat to meet my particular basic roasting profile at different times during the roast (in addition to the turbo oven adjustments) I added a 1000volt/50amp diode and SPST switch in series with the heating coil and thermostat of the base.  I used 1/4 of a bridge rectifier for the diode. Although the diode is not necessary, using a diode made the heat transfer smoother than without it when switching the base heat on and off. Be sure to use high temperature insulated wire when doing this modification.

If you have any questions, you can contact me at: coffee@[the domain name of this site]

Click here to see "My Spin on Coffee Roasting Profiles"

More Recent modification of the stir shaft