All posts by Mike Klodnicki

About Mike Klodnicki

Scientist, maker, tinkerer. Biology is art.

PID-controlled ceramic smoker

When it comes to home smokers, everyone wants a ceramic unit – their heat retention is unparalleled, meaning it takes less fuel, less smoke, and less of your attention to cook the same mass of food. Kamado-style smokers and the well-known Big Green Egg are ultra-high-end, and their prices show it. I was inspired by an episode of Alton Brown’s show, Good Eats, to develop my own solution with what I could source.  However, I needed my smoker to be large enough to hold two full racks of pork back ribs (about 18″ long racks) a couple of pork butts, or a medium sized turkey.

 Nothing here for under $1000. Photo credit:

The single hardest task was finding somewhere near Athens or Atlanta that sold enormous, unglazed terra cotta flower pots.  As an academic researcher, I have pretty well-practiced Google-fu, but it took me several weeks to find a 19.75″ diameter pot, a ‘low bowl’ that nests with the pot (for the lid), and a grill grate that perfectly fits the inner lip of the pot. I found the bowl at a local pottery yard but I had to order the pot from ($70 including shipping).


Local pottery yard, full of proud elephants

smoker x3

Grill grate fits like a damn glove.

While ribs are a relatively fast-cooking cut of meat like steaks, beef brisket, a delight I had never cooked before, is a very slow-cooking cut.  If done properly, smoking a whole point or flat of brisket would take upwards of 12 hours and I did not want to have to actively tend the smoker all day.

15 hours cook time. Worth every minute. Photo credit:

Since the smoker has an electric heating element, I realized some sort of thermostat could could solve the problem (set it and forget it!).  My research turned up the versatile PID controller, an off-the-shelf microcontroller that uses an advanced algorithm to maintain the programmed temperature parameter without overshooting – perfect for achieving and maintaining a low smoking temperature. I initially learned of the idea from Seattle Food Geek – he had already utilized a PID for application in sous vide, and I adapted the electrical design to suit my needs.  I wanted to make a modular controller box with a clean design to allow quick swapping of hardware components like heating elements (if I ever chose to dabble in sous vide).

I got all the electronics together and tested everything – not on a breadboard, because of the scale of components, but on a piece of cardboard.  I ensured all wiring and connectors near or inside the smoker were high-temperature rated and then started looking for a case.  I wanted the unit to be as small as possible, while providing adequate heat dissipation for the solid state relay. Off-the shelf ABS enclosures, or ‘project boxes,’ looked cheap and ugly and were priced much too high for what you get.  Aluminum enclosures I found were always too large or too small and hugely expensive.  And with either, I would have to worry about cutting holes for various components: the female AC socket, the GFCI outlet, the PID controller, and the toggle switch.

enclosures off the shelf

Hideous or expensive, take your pick.

Considering the prices I’d seen for off-the-shelf enclosures, custom laser-cut acrylic enclosures were actually priced competitively.  They also offered an attractive level of customization: the perfect size, precision cuts for perfect fit of components, and the ability to engrave text or images.  I would simply have to design and optimize (re: minimize) the cuts and materials needed with a .svg editor like Inkscape. I learned Inkscape slowly over a week’s time, working to design a glue-less, T-slot enclosure that would only require nuts and bolts to assemble. (Update Nov-2014: where was this software tool  when I needed it!?)


Custom laser-cut enclosure, thanks Ponoko!

Originally I wanted to make a big, creative raster on the side of the enclosure, but when I submitted the design I learned it would add so much laser-time to the job that it doubled the cost, so I skipped it.

ponoko black vector engraving sample

Sample rasters/engraving. Photo credit:

ponoko raster

I’ll admit that I saw this slogan on a sign outside a BBQ shack on the drive to Suches, GA, but the proud pig is my own addition

If I had to do it over again, I would make the whole thing out of P1 sheets of acrylic, reducing cost and giving the enclosure a more cubic form.  I also selected the cheapest acrylic (3 mm thick), which is slightly regrettable because there is too much flex at the centers of the top and bottom acrylic panels for my liking.


PID controller (press-fit) and toggle switch fit perfectly


Rear of unit has GFCI outlet for heating elements, female AC socket for power, and 3.5 mm stereo jack for the thermocouple


Fully assembled unit, approximately 3″ x 6″ x 10.5″.

The PID controller software requires one-time calibration (re: set the temperature and select the auto-tune function) to your smoker’s internal volume and choice of heating element.  Once this is done, just select your cooking temperature and add a couple of hardwood chunks to the pan every 3-4 hours.  I typically get an overshoot of less than one degree Celsius.


First brisket ever.  Please excuse the lighting – we’ve since changed the intensity and spectrum of our kitchen lighting.


Burnt ends are good for the soul.

Some Southern BBQ purists don’t care for electric smokers, but they can’t argue with these results. I’d bet my brisket on it.


Hacking Craigslist: furniture edition

A great way to fill up an empty living space is grabbing deals from the furniture section of Craigslist.  It can be a pain, and there’s a lot of poor quality goods, but if you know what you’re looking for it’s not so bad.

If you’re in a big city like SF, there’s tons of offerings.  A small town like Athens gives you a much more limited selection, but the transitory nature of being a college town can help with prices.

cl nightmare

A lot of free stuff in college towns, but I’d avoid the used bedding.

The single best way to find a good deal is to look for solid wood pieces.  Sometimes people are liquidating storage or are tired of a dated piece and have no intention of fixing it up. Sometimes they simply don’t know (or care) what it’s worth – they just want it gone.

People who don’t know what they have are just as apt to rip you off as give you a good deal, so make sure you aren’t paying for particleboard.  To avoid particleboard, pay close attention to the piece’s edges and look at underside or inside of ‘wood’ panels.  Examining dings or scratches can also reveal the true composition of a board.

buffet - before 1

Scored this puppy for $35.  It’s hideous, but made of solid wood.  Just needs some love.

With the right tools, refinishing solid wood furniture can be relatively quick and painless and will save you hundreds.


Avoid particleboard – find solid wood pieces on CL and you can create a beautiful custom bar for under $50
(well, minus the booze)

A few tips for refinishing:

  • Make sure you are sanding wood, not a veneer (!)
  • Pay attention to the grain of the wood while you are sanding – I’ve ruined hours of work with 10 seconds and an orbital sander.
  • You will want to wipe up excess stain IMMEDIATELY or it will pool in little drops, dry and create unnecessary (and sticky) sanding work for you. Pay special attention to edges and corners of wood boards.
  • Have several clean sponges/rags on hand.  Stain-soaked sponges turn rock-hard when they dry and will scratch your work in progress.


Worth the effort. Took a few hours, some sandpaper, half a can of stain, two panels of glass and new hardware (knobs).


The proper way to mount the glass would be to take apart the cabinet door frame and set the glass panel in a routed groove.  These doors did not have the grooves already cut, so I just used some 1″ wide pine strips and a bunch of rubber washers to mount the glass to the inside surface of the frame.


Cheap Ikea trivet cut in half and mounted it to the inside of the cabinet to hang martini glasses.

Diaphonization, or clearing and staining wet specimens

Several years ago, I was inspired by some images I saw on a design blog’s e-newsletter.  Iori Tomita, a Japanese ichthyologist, had composed a work he called New World Transparent Specimens.  These illuminate a new world – one to which you may never have been privy.


Image credit: Iori Tomita

I was completely blown away by the level of anatomical detail shown, and started looking into the process of creating these works of art.  Diaphonization, or clearing and staining, is essentially a process through which tissue is turned transparent, cartilage is stained blue, and bones are stained red.  I found that it is used to study anatomy and that there are standard protocols for performing this process in the lab, with only a few special chemicals required.  Of course, I immediately turned to my lab’s PI to get the ingredients.


Image credit: Adam Summers

It was not nearly as cut-and-dry as we often hope lab protocols will be.  Many of the steps in the overall process are quite forgiving, but you really must understand the rationale behind each step and the interaction between steps in order to not mess up the sequence of things and the resulting specimen.


Image credit: Adam Summers

I often compare the laboratory to the kitchen.  Cooks and scientists alike will browse existing protocols, taking note of reagents and methods used and try to understand how each of the steps contributes to the final product.  Then, the best scientists (and cooks) combine the best practices from several different existing protocols, customized and enhanced to suit their own situation, to create a result that could never be produced in cookie-cutter fashion.


Image credit: Mike Klodnicki

The clearing and staining process is definitely an art.  It is a time-consuming and painstaking process, and the slightest mistake can ruin a month’s work (and perhaps an irreplaceable specimen) in an instant. But seeing nature’s beauty revealed in such an amazing way makes all the effort worthwhile.


Budget macro photography is a post for another day.

Content Creation – at the center of a healthy web

I’ve recently come to realize that the only way to demonstrate my self-taught hobbies (whether reluctantly adopted, or  enthusiastically) is to take a tour of my house and workplace.  I’ve learned so much in the past few years, I thought I should share some of that which might help people in the future.

Athens, GA, provides a low cost of living and offers quite the bargain living space if you can escape walking distance of the University.  Still a University student, I decided to move into a stand alone house a few years ago and had way more space than furniture or money, so I got creative and resourceful to solve the problem.  I had issues as a child with how the family home was decorated (re:cluttered and dated), so I’ve paid special attention to a certain aesthetic in constructing furniture.

When you first move in to a place, what do you set up first? If you’re a student, it’s probably the couch and TV so you can crash with some Chinese food after a long day of heavy lifting.SONY DSC

I constructed my simple TV and speaker stands with some leftover IKEA shelves, 24″ black iron pipe and pipe flanges.  Total budget: $60.  I was surprised to find that the flanges were the most expensive component. I think there’s no explanation needed on construction, but I found it helpful to quickly scrub the pipe with a coarse sponge and brake cleaner to remove the factory grease.  This ended up giving them a perfectly smooth, non-greasy finish with an interesting patina.



You can get the hardware at any local hardware store, and the length of pipe puts the sound stage and LCD screen at just the right viewing height.  It’s a rock-solid setup, and quite narrow so the room feels even bigger.