Ok Guys, What's the best way to tie a variac into a roaster (FR+). I'm thinking about taking the machine apart and putting the variac on the heater coils only. If I remember the fan is rectified to dc, so a voltage drop will slow down the fan. That seems counterproductive since I want to slow the roast. Thanks, Ben homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast
Hi Ben, I just plug my FR into it, slowing down both the fan and reducing the heat. This method has one advantage and one drawback over tieing it to the heat alone. The advantage is that the temperature and airflow reduce and increase together, this virtually ensures no scorching (i.e. plenty of agitation when the temperature is high), and no rapid cool off (less air when the temperature is dropped). Almost all roasting authorities agree if the bean temperature drops during a roast, quality is compromised; and this arrangement makes this less likely. The disadvantage is that at low settings, the beans cease to move properly early in the roast. So it's hard to slow down the roast prior to the first crack. Mike gets round this by rocking his Rosto. I'm lazier and the FR has less metal to bean contact, so I let the roaster run at 85 volts for 90 seconds. The beans don't move, but since the air temperature is about 280F, they don't scorch either. They just dry out, and even up when I'm doing a blend. After that, my normal range of control voltages, 95 to 125, works just fine. So my two cents is to save yourself the bother and just plug it in. Jim On 23 Nov 2002 at 15:23, Ben Treichel wrote: <Snip> homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast
Or at least try it that way first. You might be impressed with the results.
John Abbott wrote: <Snip> That makes sense. <Snip>
From: "Ben Treichel" <Snip> I've been roasting with a variac to control the Caffe' Rosto for some time now. Just direct plugged into the variac. I've been strongly considering splitting the AC into the Rosto for independent heater and fan control. Ideally both would be controllable. Considered a second variac but leaning towards simply using a rheostat for fan control. Draw back wouldn't be able to 'boost' the fan for faster cooling. (currently I usually up the voltage to 125v during cooling cycle, especially useful during hotter months.) Could quickly switch the fan plug to the variac during cooling, but what a hassle! I believe I'd have better and faster ramp control with independent fan & heater control. Just haven't gotten around to modifying either of my Rostos yet... MM;-) Variable Variac Rockin' Rosto Roasting Miss Silvia brewin' homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast
Mike wrote: <Snip> How about a ganged pair of spdt switches? -- Rick homeroast mailing listhttp://lists.sweetmarias.com/mailman/listinfo/homeroast