Custom heaters for a DIY BBQ smoker

Spring is in the air, and with that comes savory meals cooked over the course of dozens of hours. While preparing for your yearly allotment of pork and beef, check out [Brett Beauregard]’s custom heater elements he built for a DIY wood smoker.

This build follows the very successful smoker [Brett] built last year. This year, he’s using the same toaster oven heating elements, only cut down to make the heater smaller and more efficient. Basically, [Brett] is making a small cartridge heater out of the equipment he already has.

After cutting the toaster oven heating elements to length, [Brett] reamed out the ends to expose the nichrome wire. A short hit with a TIG welder bonded the lead to the heating element. Insulated with furnace cement, [Brett] had a custom heater perfect for charring chunks of mesquite or hickory.

Meat smokers aren’t very complicated – they can be built with a flowerpot and a hotplate, and will still cook up a delicious dinner. We might have to borrow [Brett]’s technique when we build this year’s smoker.

Preheat alarm added to a basic kitchen oven

[Justin] didn’t want to keep checking if the ‘oven heating’ indicator light had gone off before popping his unbaked edibles into the oven. Many models offer a buzzer to let you know when the chosen temp is reached, but for folks who own a basic oven model there’s just a light that tells when the heating element is getting juice. Not to worry, he plied his circuit design skills and built a buzzer to alert him when the oven’s ready.

It only took a few components to accomplish the task. [Justin] uses a pair of NPN transistors triggered by a photoresistor. One transistor is responsible for switching on the buzzer, the other transistor is driven by the photoresistor and controls the base of its companion transistor (see the schematic for a better understanding).

He designed and etched a small PCB to host all the parts. As you can see above, it mounts over the indicator light and is powered by a 9V battery. There’s an on/off switch to the right so the buzzer doesn’t keep triggering while cooking, and a potentiometer allows him to fine-tune the photoresistor sensitivity.

New extruder 3D prints tasty treats using chocolate

If you’ve never felt at home with a piping bag in your hands this chocolate extruder will come to your rescue. It can replace the plastic extruder head on your 3D printer (RepRap, Makerbot, most 3-axis CNC machines, etc.), letting you turn your digital creations into decadent reality.

The head uses a progressive cavity pump to feed the chocolate from a reservoir through the printing nozzle. It’s important to keep the chocolate warm or it will set up so when [Tomi Salo] designed the print head he included a heat shroud through which warm air can be circulated. He uses a shoe dryer to source the hot hair which is patched into the heat shroud with a length of tubing.

This extruder can be 3D printed but be careful what material you use. [Tomi] mentions that PLA is ‘sort of food-safe’ but ABS is not. We wonder if the design could be altered for milling out of aluminum or stainless? At any rate, if you’re going to give it a try you might find [Tomi’s] advice on working with chocolate useful.

[via @clothbot]

Kitchen timer makes Mario your Sous-chef

[Alan] was unimpressed by the cheap ticking egg timers that grace many of our kitchens. He decided this was an execllent opportunity to ply his skills with microcontrollers. He built this kitchen timer complete with an enclosure and audible alarm.

The device is Arduino based, which makes driving the graphic LCD quite easy thanks the libraries associated with that platform. As you can see above, his user interface makes use of virtual buttons – three tactile switches whose function is listed at the top of the display.

But we think the alarm sound really earns this a place in his kitchen. He used the same hardware as that that Super Mario Bros. Toilet project to play classic video game sounds when your soufflé needs come out of the oven. We haven’t come across them ourselves, but apparently there’s a line of key chains for sale in Japan (yes, we need to plan a trip there!) that have the tunes programmed into them. They’re easy to crack open and it beats dealing with a speaker and amp circuit.

A USB-controlled Solder Reflow Oven

[Joel] of [Helion Microsystems] is at it again with his USB controlled solder reflow oven.  You may remember him from his crazy twitter-enabled Ewok model. Although these two projects are quite different, they both use the HU-320 USB breakout board that he’s in the process of getting funding for via [Pozible], or Australian Kickstarter for Yanks.

The reflow oven works using a thermocouple-enabled RS-232 voltmeter to output the temperature to the HU-320 board. [Joel] has been nice enough to provide us with the C# code to interface with many multimeters if you want to implement a similar project.  Temperature is controlled with a mechanical relay for what would appear to be a poor man’s PID controller.

Sadly, Fluke meters don’t seem to be listed, but your place of work probably wants their meter back anyway!  For another toaster reflow oven implementation, check out this [HAD] article.  Be sure to check out the video after the break for a video of the setup! (heat treat engineers may find the “recipe” format humorous).

[Read more…]