Not Just Your Average DIY Spot Welder

Microwave oven transformer spot welder builds are about as common as Nixie tube clocks around here. But this spot welder is anything but common, and it has some great lessons about manufacturing techniques and how to achieve a next level look.

Far warning that [Mark Presling] has devoted no fewer than five videos to this build. You can find a playlist on his YouTube channel, and every one of them is well worth the time. The videos covering the meat of what went into this thing of beauty are below. The guts are pretty much what you expect from a spot welder — rewound MOT and a pulse timer — but the real treat is the metalwork. All the very robust parts for the jaws of the welder were sand cast in aluminum using 3D-printed patterns, machined to final dimensions, and powder coated. [Mark] gives an excellent primer on creating patterns in CAD, including how to compensate for shrinkage and make allowance for draft. There are tons of tips to glean from these videos, and plenty of inspiration for anyone looking to achieve a professional fit and finish.

In the category of Best Appearing Spot Welder, we’ll give this one the nod. Runners-up from recent years include this plastic case model and this free-standing semi-lethal unit.

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Powder Coating with a Fluidized Bed

There’s no beating the beauty and durability of a high-quality powder-coated part. There’s just something about the look and feel of the finish that goes far beyond mere painting and makes it worth the effort and expense. The typical electrostatic spray powder-coating setup can be expensive, though, and not necessarily suitable for every workpiece.

Enter the fluidized-bed powder coating chamber, perfect for limited runs of small parts, and the brainchild of [Andrew Mayhall]. With a business providing furniture kits based on iron pipe, [Andrew] needed a way to finish flanges and fittings, and powder coating provided the best look. The fluidizer he built is a great alternative to spray coating; it blows air through a bed of fine thermoplastic granules, which causes them to act like a fluid. It’s similar to the fluidized-bed hot tub we recently featured, but on a much smaller scale and with different requirements based on the ultrafine particle size and aggregation properties of the powder. [Andrew] had to add mechanical agitation to achieve a homogeneous fluid bed, and after much experimentation he’s now able to dip preheated parts into the bed and achieve one-step powder coating. The video after the break shows some of the operational details.

Does electrostatic powder-coating sound like more of your thing? No problem – DIY solutions abound, and a homebrew oven to bake your parts may be as close as the nearest file cabinet.

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Ink-Filled Machine Badges Score Respect for Your Gear

Remember the good old days when machines had a stout metal badge instead of cheap vinyl decals, and nameplates on motors were engraved in metal rather than printed on a label with a QR code? Neither do we, but these raised brass labels with color filled backgrounds look great, they’re surprisingly easy to make, and just the thing your gear needs to demand respect as a cherished piece of gear.

The ‘easy’ part of this only comes if you have access to a machine shop like [John] at NYC CNC does. To be fair, the only key machine for making these plates is a laser cutter, and even a guy like [John] needed to farm that out. The process is very straightforward — a brass plate is cleaned and coated with lacquer, which is then removed by the laser in the areas that are to be etched. The plate is dipped in an electrolyte solution for etching, cleaned, and powder coated. After curing the powder coat with a heat gun rather than an oven — a tip worth the price of admission by itself — the paint is sanded off the raised areas, the metal is polished, and a clear coat applied to protect the badge.

Plates like these would look great for a little retro-flair on a new build like this Nixie power meter, or allow you to restore a vintage machine like this classic forge blower.

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