We all know that solderless breadboards have their limitations. All that stray capacitance can play hell with circuits, especially high-speed stuff, but they’re so darn useful that avoiding them in favor of some other prototyping method can be really hard. So we often just forge ahead, plugging in our parts and hoping for the best
A recent veteran of the breadboard battle is [Anders Nielsen], who kicked off a new project by prototyping this high-voltage boost converter on a breadboard, with mixed results. The project is a scratch-built programmer for old-school ROM chips, a task normally farmed out to a dedicated programmer, but where’s the sport in that? Besides, this is the future, and generating the 12 to 14 volts needed should be a snap. And it would be, except for the fact that his chosen chip, a MIC2288 switching boost regulator, is only available in an SMD package. Getting the chip and a few other SMD support components onto breadboard-compatible breakouts proved to be challenging, and getting it working once it was there was even more work.
A lot of the trouble was down to simple breadboarding errors, but the big problem was the input capacitance, which [Anders] had to fiddle with quite a bit to get the converter to 14 volts. The current maxes out at about 25 mA before the voltage starts dropping, which just might be enough to burn those old chips, so we’ll call this a provisional win and see what happens when he builds the rest of the programmer.
[Anders]’ experience here raises a good question: what’s the best way to prototype using fussy SMD components? PCBs are cheap enough that it’s tempting to go straight to one, but swapping parts in and out like he had to do here to get everything just right would be much harder that way. We’re not sure we know the answer, but we’re pretty sure we’ll hear your thoughts on that in the comments section.
[shoobs] relocated from Australia to Luxembourg, and was really missing the whole outdoor cooking scene that is apparently very common in those parts. Now living in a modest apartment building in the city, he had no easy way to recreate some of his favorite cooking methods — specifically that of Wok Hei (breath of a wok) — the art of Cantonese stir-frying which uses searing heat and a lot of flinging around of the food to mix it up with the burning oil. This results in a complex set of reactions utilizing smoking, caramelization, and Maillard reactions to produce the classic Cantonese smoky flavor. Not wanting an off-the-shelf solution [shoobs] took it on himself to build a balcony cooking station capable of the temperatures needed for Wok Hei, and documented it for our viewing pleasure.
The build started with sourcing a free-standing burner unit from Alibaba, which proved to be a little less powerful (at 30 kW) than ideal, but still sufficient. After locating a matching regulator and pressure gauge capable of the needed flow rate to feed the hungry burner, the next task was to construct a sturdy enough bench to mount it all. This was constructed from Douglas fir slabs, butt-jointed using a 3D printed drilling jig for ease of construction.
Using a flatbed scanner, the existing burner base was digitized in order to make a model suitable for laser-cutting a new mounting plate from steel. [Shoobs] isn’t lucky enough to have access to a metal-capable laser cutter — he sent his cad files off to a cutting service.
A second plate was mounted below with a sufficient gap above the bench to act as a heat shield. This keeps the wooden worktop safe from the heat. Whilst he was laser cutting steel, [shoobs] took the opportunity to design a few other custom parts to mount the regulator and other bits, because, why wouldn’t you? We reckon the end result is pretty nice, in a minimalist and understated way.
While it’s possible to make pizza from scratch at home right down to the dough itself, it’ll be a struggle to replicate the taste and exquisite mouthfeel without a pizza oven. Pizzas cook best at temperatures well over the 260°C/500°F limit on most household ovens while pizza ovens can typically get much hotter than that. Most of us won’t have the resources to put a commercial grade wood-fired brick oven in our homes, but the next best thing is this portable pizza oven from [Andrew W].
The build starts with some sheet metal to form the outer and inner covers for the oven. [Andrew] has found with some testing that a curved shape seems to produce the best results, so the sheet metal goes through rollers to get its shape before being welded together. With the oven’s rough shape completed, he fabricates two different burners. One sits at the back of the oven with its own diffuser to keep the oven as hot as possible and the other sits underneath a cordierite stone to heat from the bottom. Both are fed gas from custom copper plumbing and when it fires up it reaches temperatures hot enough that it can cook a pizza in just a few minutes. With some foldable legs the oven also ends up being fairly portable, and its small size means that it can heat up faster than a conventional oven too.
This is [Andrew]’s third prototype oven, and it seems like he has the recipe perfected. In fact, we featured one of his previous versions almost two years ago and are excited to see the progress he’s made in this build. The only downside to having something like this would be the potential health implications of always being able to make delicious pizzas, but that is a risk we’d be willing to take.
Melting aluminum is actually pretty easy to do, which is why it’s such a popular metal for beginners at metal casting. Building a foundry that can melt aluminum safely is another matter entirely, and one that benefits from some of the thoughtful touches that [Andy] built into his new propane-powered furnace. (Video, embedded below.)
The concern for safety is not at all undue, for while aluminum melts at a temperature that’s reasonable for the home shop, it’s still a liquid metal that will find a way to hurt you if you give it half a chance. [Andy]’s design minimizes this risk primarily through the hands-off design of its lid. While most furnaces have a lid that requires the user to put his or her hands close to the raging inferno inside, or that dangerously changes the center of mass of the whole thing as it opens, this one has a fantastic pedal-operated lid that both lifts and twists. Leaving both hands free to handle tongs is a nice benefit of the design, too.
The furnace follows a lot of the design cues we’ve seen before, starting as it does with an empty party balloon helium tank. The lining is a hydrid of ceramic blanket material and refractory cement; another nice safety feature is the drain channel cast into the floor of the furnace in case of a cracked crucible. The furnace is also quite large, at least compared to [Andy]’s previous DIY unit, and has a sturdy base that aids stability — another plus in the safety column.
Building a barbecue is a common DIY pursuit, and one that comes with a tasty payoff at completion. While many projects focus on charcoal or wood-fired designs, [Andrew] is more of a gas man. Not one to simply buy off the shelf, he designed his own burners from scratch.
This quest wasn’t just unnecessary yak shaving; burners to suit [Andrew]’s desired size and power simply weren’t available. The burner is designed around the Venturi effect, wherein the propane gas is passed through a small orifice, creating a jet and pulling air along with it as it enters the burner tube. This causes the gases to mix, and they can then be ignited when passing through the outlet holes of the burner. Get the orifice and outlet holes sized just right, and you’ll have a burner that produces a hot, blue flame, perfect for efficient cooking.
The orifice was produced with brass plumbing components, and hooked up to a valve rated for use with gas lines. The burner tube itself was created from stainless steel tube, with slots cut to act as outlet holes and with the end crimped and welded shut. A black iron pipe reducer was then used as the air inlet and orifice mount.
The final result is a powerful barbecue burner that is perfectly sized to [Andrew]’s needs. If you’re keen to build your own custom rig, you may find this a useful and cheap way to go versus sourcing parts off the shelf. We’ve seen [Andrew]’s work before, too. Video after the break.
Calling [Matt Barr]’s remote controlled hot air balloon a miniature is a bit misleading. Sure, it’s small compared with the balloons that ply cold morning skies with paying passengers and a bottle of champagne for the landing. Having been in on a few of those landings, we can attest to the size of the real thing. They’re impressively big when you’re up close to them.
While [Matt]’s balloon is certainly smaller, it’s not something you’d just whip together in an afternoon. Most of [Matt]’s build log concentrates mainly on the gondola and its goodies — the twin one-pound camp stove-style propane tanks, their associated plumbing, and the burner, a re-tasked propane weed torch from Harbor Freight. Remote control is minimal; just as in a full-size balloon, all the pilot can really do is turn the burner on or off. [Matt]’s approach is a high-torque RC servo to control the burner valve, which is driven by an Arduino talking to the ground over a 2.4-GHz RF link. The balloon is big enough to lift 30 pounds and appears to be at least 12 feet tall; we’d think such a craft would run afoul of some civil aviation rules, so perhaps it’s best that the test flight below was a tethered one.
[Makercise] is getting ready for Maker Faire. One of the things he’d really like to do is some casting demonstrations. However, he has no desire to take his expensive and heavy electric kiln based foundry to Maker Faire. So, he made his own.
He got into metal casting during his excellent work on his Gingery lathe series. He started off by modeling his plan in Fusion 360. He’d use a 16qt cook pot turned upside down as the body for his foundry. The top would be lined with ceramic fiber insulation and the lid made out of foundry cement. He uses a Reil style burner, which he also modeled as an exercise. This design is light and even better, allows him to lift the top of foundry off, leaving the crucible completely exposed for easy removal.
All went well with the first iteration. He moved the handles from the top to the bottom of the pot and filled it with insulation. He built legs for the lid and made a nice refractory cement bowl on the bottom. However, when he fired it up the bowl completely cracked along with his crucible. The bowl from design flaw, the crucible from age.
A bit put off, but determined to continue, he moved forward in a different direction. The ceramic insulation was doing so well for the top of the foundry that he decided to get rid of the cement altogether and line the bottom with it as well. The lid, however, would be pretty bad for this, so he purchased another pot and cut the top portion of it off, giving him a steel bowl that matched the top.
The foundry fires up and has worked well through multiple pours. He made some interesting objects to hopefully sell at Makerfaire and to test the demonstrations he has planned. The final foundry weighs in at a mere 15lbs not including the fuel cylinder, which is pretty dang light. Video after the break.