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Temp controller build - complete - details, cost,calibration

Posted: Tue Jul 08, 2014 10:34 am
by RickBeer
Completed my controller this morning. I built the paint can heater the other day. Had to buy the small ceiling box, otherwise had all the other parts (paint can, cord, light socket, light bulb). Over the weekend when we had spare time my son and I cut the openings in the project box, and today I assembled it. Had to buy the STC-100, the project box, indicator lights, and outlet face plate. Had the two outlets (one always live per Inkleg's suggestion), the cord, the cord clamp, pieces of wire and wire caps. Cost was:

Ceiling "pancake box" - $1.70
Face plate - $.97
Project box - $7.49
Two neon lights (hot and cold are live) - $3.99
STC-1000 - $16.40. Note the price goes up and down - I bought mine from Lerway Tech which Amazon does fulfillment for.

Total cost = $30.55 plus tax.

I'm now seeing how close the thermometer reading is, and plan on checking the defaults.

Update - it appears I'm off by 2 degrees F on the reading the box has vs. the reading my brewing thermometer has. Putting them together on the counter shows within a degree. When I go up to the cottage there are several analog thermometers so I'll pop a few in the LBK, setup the controller, and see what the error, if any, is. Curious as to whether others calibrated or not.

I'm excited to be planning my first summer brews as I usually stop at the end of June for 2 1/2 months.

Also discovered that my in-laws neighbor just got a Mr. Beer kit for Father's Day, so I'm going to help him dive in and let him use the freezer with the controller on it by both of us brewing at the same time. Plenty of room inside for lots of LBKs.

Re: Temp controller build - complete - details, cost,calibra

Posted: Tue Jul 08, 2014 11:37 am
by DaYooper
Dang, ordered my second the other week for the kegerator as it appears the thermostat no longer works well and is way too cold. Still waiting for that slow boat from Hong Kong to arrive. Having it shipped locally would have been better. Darn you eBay.

Being cheap I simply used a 3-gang box. Needed to trim a little from the cover plate to fit the STC in but that took about a minute with the Dremel.

Re: Temp controller build - complete - details, cost,calibra

Posted: Tue Jul 08, 2014 12:19 pm
by RickBeer
I'm finding that even with a piece of paper towel folded over the probe, it's reacting to the air temp too much. I tested it vs. my brewing thermometer and found a 3 degree difference between the probe outside and the brewing thermometer inside. The brewing thermometer hits zero C with a glass of ice water, so I believe it to be accurate.

So do people check this - and calibrate for it - or leave it alone?

I'm thinking of adjusting via F4 about 1.5 degrees, but interested in Borg input.

I mostly ferment with a basement air temp in the low 60s that sees the wort get to 66 or so per the stick on thermometer. My thinking is to set the controller at 63, adjusted as above, and go from there.

Re: Temp controller build - complete - details, cost,calibra

Posted: Tue Jul 08, 2014 1:25 pm
by DaYooper
I really havent had a problem taking an old sock from the "rag bag", folding it twice, and duct taping it to the outside of my fermenter with the probe sandwiched between the two. The difference seems to be within the accuracy range of my thermometer so I am happy. For the most part a degree or two aint goona kill me or my yeasties. Now, Ive only done this once when I put my first box together so dont know if that is typical or not, but the beer has been darn tasty and that is all I care about.

Re: Temp controller build - complete - details, cost,calibra

Posted: Tue Jul 08, 2014 4:36 pm
by RickBeer
Outside the frig, on the counter, it read 3 degrees F different. In the frig, it was 1/2 a degree F. However, the frig clearly showed me that the paper towel idea (1/2 sheet folded into small square) doesn't work, because it read 4 degrees C and then when I opened the door to stick in the analog thermometer it climbed quickly to 5 and then to 6.

I will try a sock or similar when I actually put it in the freezer. I'm not really worried that there is a difference - more worried that the probe reads the liquid and reacts, versus waiting for the freezer's ambient temperature to react as the LBK heats up, figure that would be a 12 hour or so delay (LBK raises a few degrees, heats air in freezer). So I may just set it to 64 instead of 66 or similar.

Re: Temp controller build - complete - details, cost,calibra

Posted: Tue Jul 08, 2014 7:14 pm
by jimjohson
Well I use a whole sheet and seldom ever open the chamber. I think the wort will help the probe not react so easy to the air temp change. Fwiw I did not check and calibrate but seems to be agreeing to my stick on thermos. Mine is in c not f so I have to refer to a chart. Set mine for 18.5c = 65.3f with a .5 variance

Re: Temp controller build - complete - details, cost,calibra

Posted: Tue Jul 08, 2014 8:39 pm
by RickBeer
Mine is also in C, I did the conversion before posting.