SC/TO Profiles / Q&A / Tips & Tricks

[ptrmorton]

I use the same thing (multiple actually) and they are still going strong after numerous roasts.  Some like a solid end probe to ride in the bean mass, but I haven't needed that.  Good luck with it.

[sea330]

I use 20 gauge solid K thermocouple wire that is very stiff, stays in the bean mass really well. the bead you refer to is the junction, it's welded not soldered, kinda like resistance welding. I have found that only thing you need to do is clean it every now and then, I found a 1/8th brass fitting that I used as a pass threw to hold the TC in place on the spacer ring. My roasts run anywhere from 12 to 14 minutes, I usually preheat around 300 to 350 deg depending on the bean.     

[ptrmorton]

I use a very similar setup to sea330 although I preheat to about 400.  Overall roasting times are about the same however.

[peter]

I use a SC/TO (actually SC/GG)

What makes a GG different than a TO? 

Also prior to hitting FC, what temps should I aim for?

i realize all beans are different, but I am aiming for full city roasts

Many people will use FC for Full City, and 1C or 2C for first and second crack, just to avoid confusion whether FC is first crack or full city.




And now, just to prove I can (at least try to) be helpful...  :-)    you'll lose some energy by having that tall of a spacer.  3" is moving the heat pretty far away from the beans, compared to a 1" spacer.

It's not easy to find a thermocouple solution that will stay put in the bean mass, and not get banged up by the beans or the stirring arm.  I'm one of those that ptrmorton referred to, who like the solid probe riding in the bean mass.  You'll get yours to work, but eventually it'll wear out, or not stay put where you want it.  I haven't seen sea330's 20ga. wire setup, but it sounds interesting.

[sea330]

Peter, I will make you up one to check out, PM were to ship it to.

Rich

[ptrmorton]

What makes a GG different than a TO? 

Nothing, I now realize in looking back at the beginning of this thread.  I was under the mistaken impression that when SC/CO was changed to SC/TO, the TO was a specific brand of convection oven similar to when SC was changed to UFO when the Salton base was being referred to instead of the Stir Crazy.

you'll lose some energy by having that tall of a spacer.  3" is moving the heat pretty far away from the beans, compared to a 1" spacer.

I completely agree that a 1" spacer makes the roaster more responsive to changes in the heat being applied to the bean mass.  I struggled with a 3" spring form pan until I saw the light.

[ptrmorton]

Antoine_t, I also highly recommend two temperature probes - one for the bean mass and the other for what you refer to as environmental temperature.  After a couple of months of trial and error and attempting to duplicate other’s roasting profiles when I first switched to a SC/TO, I began focusing on how much heat energy I was pouring into the bean mass based upon the difference between environmental temperature and bean mass temperature.  This helped me compensate for one of the drawbacks of SC/TO roaster compared to more sophisticated roasting systems – the inaccuracy and on/off nature of the controls on the TO.  By focusing on the difference between environmental temp vs bean mass temp, some of the guess work during the roasting process (especially during 1C) was reduced and my consistency was increased regardless of bean type (big help with my early decaf experiences).

Furthermore, when roasting very small samples, my bean mass temperature would bounce around and not be reliable.  Sometimes bean mass temps would appear to be falling when what was actually happening was I was finally getting a more accurate reading after the probe had been partially exposed to the environmental temperatures.  By knowing that I had an approximately 60 degree difference between bean mass temp and environmental temp, I was assured that I was not close to stalling the roast and there was no need to unnecessarily add more heat regardless of apparent falling bean mass temperatures.  The two probe setup also allows for much gentler roasts without fear of stalling which I find useful after 1C.

[antoine_t]

After mounting a 60 rpm motor on my SC The bean agitation made all the difference, I struggled with the stir arm. I finally ended up mounting two original stir arms on top of each other seems to work good. roasting 1.2 pounds at a time works great, if I get a order of a pound I don't need to fire up my 2 Kilo roaster, much less hassle and more efficient. I am using a GG 1500 watt turbo oven and the SC element hooked up with a inline switch in case I need to push it, rarely ever need to use it.

Yes, I will post pics as soon as my camera charges up. Everything was purchased off ebay, I'm into it for $37.00 and my time about a couple hours to install. The motor has plenty of power runs at 14 watts 60 rpms, found a stick of 11/16 aluminum round stock for the shaft, drilled a 7mm hole to  connect the motor shaft and a 1/4 20 bolt on the stir arm end.

Motor
http://www.ebay.com/itm/351134319741 $21.00
trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Motor shaft 11/16 aluminuum round stock, I had them cut it into 12" lenghths.$7.00
http://www.ebay.com/itm/150297434120?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Step-up converter $about $7.00
http://www.ebay.com/itm/STEP-UP-VOLTAGE-CONVERTER-110V-to-220V-TRANSFORMER-50W-/221224331625?pt=LH_DefaultDomain_0&hash=item3381ff6969

Simple instalation, mounted the motor with sheet metal screws on the metal access plate on the bottom of the SC.Built 4 of them for Family and freinds, havent had one fail in a year going strong

any chance you have any of the 11/16 aluminum round stock for the shaft drilled to fit the 7mm motor left?

i finally purchased the 60rpm motor off ebay

thanks again

[sea330]

Yes I have one, I would be happy to send it to you. It is drilled out to 7mm shaft, 3" long with set screw.

[sea330]

Sorry for the bad pic my pic resizer keeps messing up, PM me your address and i will get it to you.

[antoine_t]

Sorry for the bad pic my pic resizer keeps messing up, PM me your address and i will get it to you.

awesome thanks!

ps: might need some help with putting it all together once things arrive

[sea330]

 I would be glade to help, few little tricks I learned along the way on my modifications.

[antoine_t]

Hey guys here is my modified SC/TO.  I actually have a Presto Electric Stirring Popcorn Popper that I purchased from a walmart.  The original motor was 4/5rpm, and painfully slow, resulting in uneven roasts (not sure how I tolerated it for so long!) 


Anyway, much thanks to sea330 for helping me out out tremendously.  He supplied me with the aluminum shaft you see in the middle as well as much guidance through out.   

It is now spinning at 60rpm and roasts couldn't have been better.  I have a variac that I use to control the power/heat source as well as a temp probe.


I use to have a long temp probe that would hang over the top and touch the beans to measure bean temp, but am deciding if I should drill a hole into the plate and stick a probe from underneath?  My only concern would be would I need some food grade sealant to seal in the heat after the hole is made for the probe...or can I live without it.

[sea330]

Fantastic job, haven't been able interact much, been in Vegas for the last month or so, the wife had open heart surgery crashed a couple of times ended up with a stroke, no use of the right foot, my world and hers will never be the same., glade to be back roasting again feeding my obsession. Just finished building a SC/TO modified for a friend, I have 5 people locally roasting this way and they love it, they buy greens from me at cost. Glad to hear your up and running.

Rich

[peter]

I concur - very nice build!  Those are some spiffy arms too!

As for your probe placement, going through the base will depend somewhat on the type of probe and whether you can mount it in way that the stirring arms don't collide with it.

I tried that with a bead-type wire probe, and it got beat up by the arms.  So I now have a metal probe with the pointy tip that just rides in the bean mass.  Remember that you'll want to remove the probe to dump the beans, or disconnect it from the thermometer if you have to move the base unit to where your bean cooler is.