We know, we know. Getting PCBs professionally fabricated anymore is so cheap and easy that making them in-house is increasingly becoming something of a lost art. Like developing your own film. Or even using a camera that has film, for that matter. But when you’re in Brazil and it takes months for shipments to arrive like [Robson Couto] is, sometimes you’re better off sticking with the old ways.
[Robson] writes in to tell us how he decided to buy a ~$150 CNC “engraver” kit from an import site, in hopes that it would allow him to prototype his designs without having to use breadboards all the time. The kit turned out to be decent, but with a series of modifications and a bit of trial and error, he’s improved the performance significantly and is now putting out some very nice looking boards.
The primary hardware issues [Robson] ran into were in the Z axis, as some poor component selections made the stock configuration wobble a bit too much. He replaced some flimsy standoffs as well as swapping in some bushings he salvaged from dead inkjet printers, and the movement got a lot tighter.
Despite the fact that the version of Grbl flashed onto the engraver’s cloned Arduino Uno supports Z leveling, it’s not actually enabled out of the box. [Robson] just needed to add some extra wiring to use the spindle’s bit as a probe on the copper clad board. He also went ahead and updated to the latest version of Grbl, as the one which ships with the machine is fairly old.
He wraps up the post by going through his software workflow on GNU/Linux, which is useful information even if you’ve taken the completely DIY route for your PCB mill. If you’d like to know more about the ins and outs of milling your own boards, check out this excellent primer by [Adil Malik].
Continue reading “Turning A Cheap Engraver Into A Decent PCB Mill”
Is twenty times the copper twenty times as much fun to work with? Ask [limpkin] and follow along as he fabricates a DC/DC block for a Formula E race car on 20-oz copper PCBs.
The typical boards you order from OSH Park and the like usually come with 1-ounce copper – that’s one ounce of copper cladding per square foot of board. For those averse to Imperial units, that’s a copper layer 34 micrometers thick. [limpkin]’s Formula E control board needs to carry a lot of current, so he specified 700-micrometer thick cladding, or 20-oz per square foot. The board pictured cost $2250, so you’d figure soldering on the components would be an exotic process, but aside from preheating the board, [limpkin] took it in stride. Check out the image gallery of the session and you’ll see nothing but a couple of regular high-wattage soldering irons, with dirty tips to boot.
It’s pretty neat comparing what’s needed for power electronics versus the normal small signal stuff we usually see. We’d recommend looking at [Brian Benchoff]’s “Creating a PCB in Everything” series for design tips, but we’re not sure traditional tools will work for boards like these. And just for fun, check out the Formula E highlights video below the break to see what this build is part of.
Continue reading “Massive 20-oz. Copper PCB Enables Electric Racing”
If you can 3D print most of the parts for another 3D printer, why not also for a PCB mill? That’s the question answered by the Cyclone PCB Factory. It will help you kiss those toner transfer or photo resist days goodbye.
Homemade circuit boards tend to be rather small, which really helps keep the cost and scope of this project down. Most of the mounting parts, as well as the gears, are 3D printed. Of course there’s the usual machine tool items which you pretty much have to purchase: the ball screws, precision rod, stepper motors, and a motor to spin the routing tool.
Check out the video below to see where the project is right now. One of the crucial aspects of PCB milling is to have a level build table. The cutter head tends to be ‘V’ shaped so cutting just a bit too deep can blow out the traces you’re trying to isolate. The demo shows that this can automatically calibrate the software to account for any variances in the height of the copper clad.
We remember seeing a snap-together PCB mill. But we’re pretty sure that that one used parts milled from HDPE rather than 3D printed components.
Continue reading “Cyclone PCB Factory: 3d Printable Circuit Board Mill”
If you’re looking to build some small radio circuits, or if you are simply seeking a new look for your PCBs, you might want to check out what YouTube user [AndyDaviesByTheSea] has been working on lately. He has been building RF circuits as of late and was searching for a better way to create islands or “lands” on copper-clad PCBs.
He says that these sorts of islands are traditionally cut into the PCB with a scalpel or file – hardly an efficient process. [Andy] did a little experimenting and found a great way to quickly and precisely cut lands with a drill. Borrowing a bit of metal from an old VHS tape, he crafted a circular land cutter with a metal file. When mounted as a drill bit, his cutter produces clean, shallow cuts which create perfect lands on which to solder his components.
The only drawback to this method is that [Andy] found his bits were being dulled by the fiberglass boards pretty quickly. His solution was to carefully grind a broken heavy duty drill bit to do the task, which he says works even better than his original cutter.
If you’ve never heard of “Manhattan Style” circuit construction, you’re not alone. Popular in ham radio circles, the process looks nicer than straight dead bug style circuit building, but not as involved as etching your own PCB – consider it a nice middle of the road solution.
This type of construction is often used to build circuits inside enclosures that are made of copper clad, which is a somewhat common practice among ham radio operators. Manhattan Style circuits are built using glued-on metal pads to which components are mounted. One might think that the large pads you see in the image above would limit you to through-hole components, but that’s definitely not the case. A wide array of SMD pads are available in common pin configurations as well, allowing you to use pretty much any type of component you prefer.
While it might not be appropriate for every project you work on, Manhattan Style circuits and copper clad boxes definitely add a nice touch to certain items, like the Wheatstone Bridge Regenerative Receiver you see above.
Building a great looking box for your projects can be a challenge. [Ken] boils down his process of building enclosures out of copper clad (PDF) circuit board material into an illustrated guide in case you want to try this for yourself. Why would you want to use PC board? The fiberglass substrate makes for a strong and lightweight material. Also, [Ken] is a ham radio operator and the copper coating acts as an electrical shield for delicate components inside.
As you can see above he uses solder to tack the pieces together. There’s some important considerations that go along with this method. First, he cuts the pieces just a bit oversized and then sands them flat and square before assembly. Next, he uses some 20 gauge wire as a shim between a ninety-degree joint and a right angle jig. This shim compensates for the shrinking that occurs as the solder cools, making sure the joint gets pulled to a right angle. He even solders nuts in place so that screws can be used to attach the case cover to the chassis.
Yesterday we saw toner transfer used to make labels on an ABS case. If you make your enclosure out of copper clad, using toner transfer for panel labels will be a snap!
[Rhys Goodwin] has been working on a system to print resist onto copper clad using an inkjet printer. This is a toner transfer alternative as it still uses toner, just not quite as you’d expect. The first step is to modify an inkjet printer, separating the carriage from the feed rollers in order to increase the clearance for the substrate. Instead of printing with etch resistant ink, as we’ve seen before, [Rhys] prints with black ink and then covers the board (ink still wet) in laser toner. Once there’s good adhesion he blows off the excess and bakes the board in a sandwich press, with spacers to keep the iron from touching the surface of the copper clad. This cooks the resist into a hard plastic layer and the board is ready for the acid. Watch him walk you through the process after the break.
[Rhys] uses the same method for silk screen, printing in red and baking the ink onto the substrate without added toner. This produces a nice looking board but it’s still quite a bit of work. It certainly sheds more light on the process than that laser-printer method from back in May. We hope you’ve been inspired by this and come up with the next innovation that makes this process easier.
Continue reading “Direct To PCB Inkjet Printing”