Chemotransfer for DIY PCBs

Making PCBs with the toner transfer method has been around since you could buy your traces at Radio Shack. There are a million techniques for removing copper from sheets of fiberglass, from milling to using resist pens, to the ubiquitous laser printer toner transfer. Here’s a technique we haven’t seen before. [Darko Volk] is calling this ‘chemotransfer’. It’s mostly a laser printer toner transfer process, but the toner is transferred from paper to copper with the help of a special mix of solvents.

This chemotransfer process is almost identical to the usual process of making a toner transfer PCB. First, the design is printed in reverse on dextrin-coated paper, the paper is placed down on polished copper, the entire assembly is sent through a laminator, and finally the board is etched with the chemical of your choice. The key difference here is a solvent applied to the copper just before the design is laid down. [Darko Volk] made a mixture of 25% “cleaning petrol” (benzene, naphtha, or gasoline, or some sort of light hydrocarbon, apparently), 5% linseed oil, and 70% isopropanol. This apparently aids in releasing the toner from the paper and sticking it down to the copper.

From there, the process is effectively a standard toner transfer process. [Darko Volk] is using a solution of sodium persulphate for the etch, and rigged a camera up to a CNC machine for the drilling.

This process can be expanded to two-layer boards very easily using a light table to align the layers of paper before placing them down on the copper. You can check out a video of the fabrication of a single side and double sided board below.

Thanks [Andrej] for the tip.

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Make a PVC Drill Press

There are two types of people in this world: people who think that PVC is only suitable for plumbing, and people who don’t even know that you can use PVC to carry water. Instructables user [amjohnny] is clearly of the latter school. His PVC Dremel drill press is a bit of an oldie, but it’s still a testament to the pipefitter’s art. And you can watch it in action in the video embedded below.

Things we particularly like about this build include the PVC parallelogram movement, springs around tubes to push the Dremel head back up, and the clever use of a T-fitting and screw plug to hold the press in its lowest position. We wonder how one could add a depth stop to this thing. No matter, we love watching it work.

Anyway, this is just one hack of many that emphasizes the importance of a drill press in basically anyone’s life, as well as the ease of DIY’ing into one. If you’re in the PVC-haters camp, but have some scrap wood and drawer slides or plastic offcuts lying around, you have the makings of a rudimentary press — a welcome tool in the shop.

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Foot Pedal Switch Specifically Made For PCB Drilling

Using the Toner-Transfer and Etch method for making prototype circuit boards is fairly common. One downside to this process is that any holes still need to be drilled. [Giorgos] hand drills boards all the time. He has a Dremel with a drill press attachment but he still prefers using a small pen-style mini drill to make the holes. There is one problem with this tool though, the on/off switch is in an non-ergonomic location. After flipping the switch tens of times during a drill job, [Giorgos] has felt some digit discomfort. He knew there had to be a better way.

His solution: a foot pedal on/off switch. This isn’t some off-the-shelf foot switch, [Giorgos] made it from parts and pieces kicking around in one of his junk drawers. The foot pedal frame is made from acrylic sheet. A couple of hinges allow the pedal to press down on an old switch, very similar to the ones found in guitar effect pedals. This switch was heavy-duty and had a strong spring that easily pops the switch and pedal back up after being pressed.

Wiring was easy, the positive lead of the DC wall wart was split and attached to the pedal’s switch. Pressing the switch makes or breaks the power connection, turning the hand-held drill on and off. [Griorgos] solve his ergonomic problem and cleaned out his junk drawer without spending a dime. We’d say that’s a triple win!

PCB Drill Press Gets a Microscopic Upgrade

If you get into more complicated PCB design, you’ll find the need to drill tiny and accurate holes much more often. Wouldn’t it be nice to have a precise way of doing that? Maybe even something as simple as strapping a $10 USB digital microscope to it?

That was [mlerman’s] thought anyway, and from the looks of it, it seems to work quite well! If you already have a PCB drill press then it’s just a matter of installing the microscope opposite the drill — align it to the center point with some cross hairs and boom you’re in business.

But if you don’t yet have a PCB drill, [mlerman’s] got you covered there too, as he explains in great detail how to modify a cheap drill press into an inverted PCB drill press.

Inverted PCB Drill Press

Wait, why is it inverted? Besides making more room for the USB microscope to sit, it also ensures the microscope lens doesn’t get covered in the PCB fairy dust that would fall on it if it were in a normal orientation.

[via Embedded-Lab]

DIY Mini-Drill Would Make Mad Max Proud


That’s not a prison tattoo gun up there, it’s [Szabolcs] DIY mini drill. Hackaday has been on a bit of a DIY tool kick lately – with improvised saws, grinders, and grinders converted to saws, among other things. We haven’t had any DIY drills yet, though. [Szabolcs] needed a drill for his home-made printed circuit boards. Usually a Dremel or similar rotary tool is pressed into service for drilling PCBs. However, for some reason he didn’t have access to one. [Szabolcs] called upon his inner MacGyver and built a drill from parts he had on hand.

Every drill needs a chuck, or at least a collet holder. This drill’s chuck is sourced from a drafting compass. Long ago in the dark ages before CAD, mechanical drawings were manually drawn up. Companies employed entire drafting departments to draw designs, blueprints, and schematics. These draftsmen used the compass to create accurate circles and arcs. [Szabolcs] re-used the lead holder from the compass as a chuck for his drill. A 540 or 550 brushed sealed endbell can motor, common to the R/C cars spins the drill up. We originally thought [Szabolcs] used an Erector or Meccano set piece as a shaft coupling. The truth is it’s the internals of a Euro style terminal strip. A small tactile button is used to activate the motor. Some electrical tape wrapped around the motor holds the button in place. The tape also makes sure that the user isn’t cut by the sheet metal field ring wrapped around the can. Power for the system can come from just about anywhere, though [Szabolcs] says he uses the 12v rail of an old ATX power supply.

Cheap, Resourceful DIY Mini CNC Router/Mill Contraption

Few Hackaday Readers would disagree with the classic phrase: Necessity is the mother of invention. That statement is certainly no exaggeration when it comes to this mini 3-axis CNC Machine. The builder, [Jonathan], needed a way to prototype circuit boards that he designed. And although he admittedly doesn’t use it as much as he intended, the journey is one of invention and problem solving.

[Jonathan] started from the ground up with his own design. His first machine was a moving gantry style (work piece doesn’t move) and ended up not performing to his expectations. The main problem was alignment of the axis rails. Not becoming discouraged, [Jonathan] started on version 2. This time around the work piece would move in the X and Y directions like a conventional vertical milling machine. The Porter-Cable laminate trimmer would move up and down for the Z axis. It is clear that the frame is built specifically for this project. Although not the prettiest, the frame is completely functional and satisfactorily stiff for what it needs to do.

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Hackaday Links: June 22, 2012

For when you want something huge machined

Turn your volume down for this video. It’s the HSM-Modal CNC mill carving a full-sized car out of styrofoam, applying clay to the foam core, and machining the clay at 50 meters per minute. Yes, we’ve seen this machine before, but never in action. It only took a little over 24 hours to make this full-size model car.

Microscope into a drill press

If you need to drill some PCBs, [wotboa] has a neat build for you. He built a micro drill press out of a microscope. It’s a damn good idea if you can find a quality microscope base; those things usually have exceptionally high precision. The ‘hack’ part is a $7 Harbor Freight rotary tool, some PVC pipe, and a PWM control for the motor – home-made, natch.

I’m telling you, they need to get [River] out of the library. Work on it [Moffat].

[Alan] made a TARDIS book case, and he decided to share the plans with us. Just the build to combat the severe lack of woodworking and Whovian stuff on Hackaday. Vashta Nerada hopefully not included.

Money can’t buy happiness, but you sure can sell it

[Greg] sent in some info on Disney’s ‘glow with the show’ hats they sell at the California Adventure park. For $25, you get a hat with RGB LEDs in the mouse ears that synchronize with the World of Color show every night. There’s a better description of the hats here, but we’re thinking these are very similar to the Coldplay Xylobands we saw at this year’s Grammys. Anyone want to tear some mouse ears apart?

An exceptionally low-tech radio telescope

[Impulse405] found a poor man’s radio telescope on Instructables and decided to share it with us. [Z0rb] found a 10-foot dish in the garbage and quickly absconded with this retro hardware. After adding a power supply and a meter-based total power receiver, [Z0rb] had a radio telescope that covered wavelengths from 850 to 2200 MHz.