A Soldering LightSaber For The Speedy Worker

March 28, 2020 by Jenny List 18 Comments

We all have our preferences when it comes to soldering irons, and for [Marius Taciuc] the strongest of them all is for a quick heat-up. It has to be at full temperature in the time it takes him to get to work, or it simply won’t cut the mustard. His solution is a temperature controlled iron, but one with no ordinary temperature control. Instead of a normal feedback loop it uses a machine learning algorithm to find the quickest warm-up.

The elements he’s using have a thermocouple in series with the element itself, meaning that to measure the temperature the power must be cut to the element. This duty cycle can not be cut too short or the measurements become noisy, so under a traditional temperature control regimen there is a limit on how quickly it can be heated up. His approach is to turn it on full-time for a period without stopping to measure the temperature, only measuring after it has had a chance to heat up. The algorithm constantly learns how long to switch it on to achieve what temperature, and is able to interpolate to arrive at the desired reading. It’s a clever way to make existing hardware perform new tricks, and we like that.

He’s appeared on these pages quite a few times over the years, but perhaps you’d like to see the first version of the same hardware. Meanwhile watch the quick heat up in action with a fuller explanation in the video below.

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Can Solder Paste Stencils Be 3D Printed? They Can!

March 27, 2020 by Donald Papp 37 Comments

3D printed solder paste stencil, closeup.

[Jan Mrázek]’s success with 3D printing a solder paste stencil is awfully interesting, though he makes it clear that it is only a proof of concept. There are a lot of parts to this hack, so let’s step through them one at a time.

First of all, it turns out that converting a PCB solder paste layer into a 3D model is a bit of a challenge. A tool [Jan] found online didn’t work out, so he turned to OpenSCAD and wrote a script (available on GitHub) which takes two DXF files as input: one for the board outline, and one for the hole pattern. If you’re using KiCad, he has a Python script (also on GitHub) which will export the necessary data.

The result is a 3D model that is like a solder paste mask combined with a raised border to match the board outline, so that the whole thing self-aligns by fitting on top of the PCB. A handy feature, for sure. [Jan] says the model pictured here printed in less than 10 minutes. Workflow-wise, that certainly compares favorably to waiting for a stencil to arrive in the mail. But how do the actual solder-pasting results compare?

3D printed solder stencil on PCB, after applying solder paste.

[Jan] says that the printed stencil had a few defects but it otherwise worked fine for 0.5 mm pitch ICs and 0402 resistors, and the fact that the 3D printed stencil self-registered onto the board was a welcome feature. That being said, it took a lot of work to get such results. [Jan]’s SLA printer is an Elegoo Mars, and he wasn’t able to have it create holes for 0.2 mm x 0.5 mm pads without first modifying his printer for better X/Y accuracy.

In the end, he admits that while a functional DIY solder stencil can be 3D printed in about 10 minutes, it’s not as though professionally-made stencils that give better results are particularly expensive or hard to get. Still, it’s a neat trick that could come in handy. Also, a quick reminder that we stepped through how to make a part in OpenSCAD in the past, which should help folks new to OpenSCAD make sense of [Jan]’s script.

Another PC Power Supply Project

March 24, 2020 by Al Williams 14 Comments

Economy of scale is a wonderful thing, take the switch-mode power supply as an example. Before the rise of the PC, a decent multi-voltage, high current power supply would be pretty expensive. But PCs have meant cheap supplies and sometimes even free as you gut old PCs found in the dumpster. [OneMarcFifty] decided to make a pretty setup for a PC supply that includes a very nice color display with bargraphs and other niceties. You can see the power supply in action in the video below.

The display is a nice TFT driven by an Arduino Nano. The project uses ACS712 current sensor modules, which are nice Hall effect devices that produce a linear output for current and have over 2 KV of voltage isolation.

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Equipping A Workshop Using Plywood And Handheld Power Tools

March 24, 2020 by Danie Conradie 18 Comments

Properly equipping a home workshop for the DIY discipline of your choice can often end up costing more than we would like to admit, and is a never ending process. [JSK-Koubou] is doing exactly that, except he is building almost all of his equipment using plywood, hand-held power tools and a LOT of attention to detail.

As far as we can tell the series really got started with a humble hand-held circular saw guide, with every tool being used to build more tools. So far the list boasts more than 50 different videos of tools built around a drill, circular saw, jigsaw, router, planar or grinder. This includes a wood lathe, drill press, jointer and various drills guides and sanders. The level of precision each tool almost eye watering. He even pulls out a dial gauge on some builds to check alignment. We honestly didn’t know plywood equipment could look this good and work so well. Check out the YouTube playlist after the break to see for yourself.

Previously we also covered [JSK-Koubou]’s set of perfectly tuned wooden speaker enclosures, the craftsmanship is really something to behold. For more impressive homebuilt hardware, take a look at this 8-axis camera crane built by another YouTuber for his home shop. Continue reading “Equipping A Workshop Using Plywood And Handheld Power Tools” →

A Boring Tale With Six Sides

March 23, 2020 by Jenny List 18 Comments

Making a hole in a piece of material is a straightforward process, after all most of us will have some form of drill. If we need a hole that isn’t round though, after the inevitable joke about bad drill control leading to oval holes, what do we do? Get busy with a file perhaps? Or shell out for a shaped punch? [Skunkworks] has taken a different tack, using LinuxCNC and a vertical mill to machine near-perfect hexagonal and other polygonal holes.

The tool path appears to be more star-shaped than polygon shaped, the reason for which becomes apparent on watching the videos below the break as the rotation of the tool puts its cutting edge in a polygonal path. Anyone who has laboured with a file on a round hole in the past will be impressed with this piece of work.

The latest in the saga takes the work from simple hexes into other shapes like stars, and even tapered polygonal holes. These in particular would be a significantly difficult task by other means, so we look forward to what other developments come from this direction.

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Screwy Math For Super Fine Adjustments: Differential Screws

March 21, 2020 by Danie Conradie 38 Comments

For any sort of precision machine, precision adjustability is required. For the hacker this usually involves an adjustment screw, where the accuracy is determined by the thread pitch. This was not good enough for [Mark Rehorst] who wanted adjustment down to 10 μm for his 3D printer’s optical end-stop, so he made himself a differential adjustment screw.

Tiny adjustment can be made to the green block due to the thread pitch differences

Differential screws work by having two threads with a slightly different pitch on the same shaft. A nut on each section of thread is prevented from rotating in relation to the other, and when the screw is turned their relative position will change only as much as the difference between the two thread pitches.

The differential screw in this case started life as a normal M5 bolt with a 0.8 mm thread pitch. [Mark] machined and threaded section of the bolt down to a M4 x 0.7 mm thread. This means he can get 0.1 mm (100 μm) of adjustment per full rotation. By turning the bolt 1/10 rotation, the relative movement comes down to 10 μm.

This mechanism is not new, originating from at least 1817. If you need fine adjustments on a budget, it’s a very elegant way to achieve it and you don’t even need a lathe to make your own. You can partially drill and tap a coupling nut, or make a 3D printed adapter to connect two bolts.

Fabricating precision tools on a budget is challenging but not impossible. We’ve seen some interesting graphite air bearings, as well as a 3D printed microscope with a precision adjustable stage.

Used Soda Stream Cylinder Becomes DIY Canned Air

March 17, 2020 by Donald Papp 16 Comments

Soda Stream machines use a cylinder of compressed CO2 to carbonate beverages, and cylinders that are “empty” for the machine’s purposes in fact still have a small amount of gas left in them. User [Graldur] shared a clever design for using up those last gasps from a cylinder by turning it into a makeshift compressed air gun, the kind that can blow crumbs or dust out of inconvenient spots like the inside of a keyboard. It’s 3D printed in PETG with a single seal printed in Ninjaflex.

[Graldur]’s 3D printed assembly screws onto the top of an “empty” cylinder and when the bottom ring is depressed like a trigger, the valve is opened slightly and the escaping gas is diverted through a narrow hole in the front. As a result, it can be used just as you would a can of compressed air. The gas outlet even accommodates the narrow plastic tubes from WD-40 cans (or disposable compressed air cans, for that matter) if more precision is required.

The design is intended for use with nearly-empty cylinders, but even so, [Graldur] also points out that it has been designed such that it can never fully actuate the cylinder’s release valve no matter how hard one presses, so don’t modify things carelessly. We also notice the design keeps the user’s hand and fingers well away from the business end of things.

This device also reminds of somewhat of a past experiment which used 3D printing to create serviceable (albeit low pressure) 3D printed compressed air tanks in custom shapes.