Built-in undercounter (or stand-alone) Sous Vide/temperature controller (STC-1000-based)

thingiverse

A plug-and-play undercounter Sous Vide/temperature controller made from readily available parts. This control allows precise temperature adjustment of any heating device simply by turning its power on or off. Its many uses include home-brewing, Sous Vide cooking, and sourdough baking. While the kitchen is a primary location for this control, I have also installed one in my garage workshop. One can pre-assemble the mount alone in a less used area since the controller can be easily detached from its mount and relocated to another mount located elsewhere. This way, an entirely separate controller does not need to be made for each location. In the past, I have built similar controllers in unmounted form, but it occurred to me that recasting them as pre-assembled, plugged-in appliances increases their ease of use and reduces the hassle of having to take them out, find a suitable location, plug them in, only to reverse the process once they've been finished using. This design features a slide-in mount with a snap feature, a front panel cubby-hole for storing the temperature probe when not in use, and a cable wrap underneath for storing the probe's cable. The unit is designed to remain plugged in and can be turned on via a rear-mounted AC switch. The heating device to be controlled is plugged into an AC socket located on the left side of the case. One advantage of its slide-in mount is that it allows moving the controller from one location to another for use in lesser-used areas such as a garage, project room, or workroom. Less obvious is that the cord wrap feature doubles as feet to enable stand-alone use. When used as a standalone device, its feet angle the front panel upwards (compared to when it's mounted) to preserve an optimal viewing angle. Assembly requires careful planning, especially mounting the main case components. My suggested order of assembly for the main case is: A) Pre-wire mini audio jack and install first. Since there's minimal engagement between the locking nut and the jack, I've found it best to pre-install its mating plug to trap the nut, then use a pair of long-nosed pliers to twist the jack's body to catch the threads. B) Install the STC-1000. You will likely need a pair of thin, long tweezers to attach the locking clip. C) Delay installing the AC socket until after you have assembled and wired the rear cover components, leaving the loose wires for the AC socket. D) With the rear cover still detached, thread the wires for the AC socket through its opening in the main case and solder the socket onto the wires while it's outside the case. E) Snap the AC socket into the case, then carefully fold all wires above the STC-1000 and close. Tip: To attach melt-in threaded brass fittings, I found it convenient to place a bamboo skewer into its hole in the front cover, drop the brass fitting onto the skewer, heat it with a soldering iron, and press it in. When it's more than halfway sunk into the plastic, remove the skewer and complete the install with the soldering iron alone. Please note that this project involves working with 120VAC wiring and power, so only consider it if you're fully knowledgeable about residential AC wiring and safety practices. Parts list: (1) STC-1000 temperature controller (readily available) (1) AC SPST rocker switch - (DigiKey part #EG5676-ND or equivalent) (1) 2.5mm audio jack - (DigiKey part #486-3395-ND or equivalent) (1) 2.5mm audio plug - (DigiKey part #CP3-1004-ND or equivalent) (1) 10k NTC thermistor probe - (DigiKey part #495-2171-ND or equivalent) (1) Philmore 65-1050 - SJT 16/3 strain relief or equivalent (1) Grounded (3-conductor) appliance cord and plug (4) 6-32x1/4" machine screws (4) 6-32 brass melt-in insert nuts But where's the schematic? Apologies in advance for not providing a schematic, but this should only be attempted by those familiar enough with AC wiring to readily deduce the schematic themselves. However it is very basic and not much more complicated than wiring a household wall switch. Top areas for future improvement: 1) The living hinge snap is too stiff and could use a redesign... 2) An IEC input power module for the AC entry would be a nice improvement, incorporating both switch, fuse (non-existent in the present design), and IEC AC cord socket.