Make Your Own Plastic Friction Welder

[Fran] shows us how to build a plastic friction welder. It’s a method of connecting plastic pieces. While it’s new to us, apparently this type of tool was given to kids about forty years ago to use with craft project (when plastic was all the craze).

The tip of the friction welder is a styrene rod. If it’s spun fast enough the friction will cause the material to heat to the melting point, depositing a bead of styrene into the joint. The tool seen here is a cheap DC rotary tool acquired from Harbor Freight. It really did a horrible job, but [Fran] discovered that it was the power supply that was under-rated. When she replace the wire that feeds it and used her bench supply it spit out 16,000 rpm without any trouble. The welding rods can be found at the craft store and fit the chuck of the tool quite nicely. You can see her demo in the video after the break. The seam she’s working on comes out very strong, surviving a slew of violent whacks on the workbench.

We’ve seen a few other methods of welding plastic. One used a tool much like a soldering iron, the other depends on ultrasonic waves and clamping pressure.

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USB Microscope Used For Soldering Very Small Things

solder

Lasik eye surgery is pretty common these days, but there are of course easier and cheaper ways to solder SMD components. [techpawpanda] wanted a video camera to see what was going on when he placed and soldered very tiny components on his board, but commercial SMD video cameras were terribly expensive. He wound up using a USB microscope to place and solder these tiny parts, and we’re thinking his SMD soldering station is the bee’s knees.

[techpawpanda]’s video-based SMD station is built around a USB microscope available at the usual online retailers for $40. This camera is mounted on a wooden base with a USB hub allowing the camera to be plugged in along with a few USB LED lights and a USB fan for a rudimentary form of fume extraction.

The results are impressive – even at 11x magnification, [techpawpanda] can put paste on pads and place even the smallest SMD parts. All this in a device that is small enough to fit in a shoe box, or be tucked neatly away whenever it is not needed.

A Portable CNC Mill

Proxxon

Second only to a lathe, a mill is one of the most useful tools to have in a shop. For [juppiter], though, a proper multi-ton mill would take up too much space and be a considerable investment. His solution to his space problem is actually very clever: he converted a small, inexpensive benchtop mill to CNC control, and put everything in a nice box that can be tucked away easily (Italian, here’s the translation).

The mill [juppiter] chose for the conversion was a Proxxon MF70, a very small mill made for jewelers and modelers. After buying a CNC conversion kit that included a few NEMA 17 motors, bearings, and mounting plates, [juppiter] set to work on driving these motors and controlling them with a computer. For the stepper drivers, a few industrial motor drivers were sourced on eBay, driven by an i3 miniITX computer built into the mill’s box. Control is through a touchscreen LCD and a Bluetooth keyboard and mouse.

So far, [juppiter] has crafted a very elegant wood and brass CNC controller that allows him to jog the axes around and set the home position. It’s an excellent build that really shows off the power and ability of these inexpensive desktop mills.

Ask Hackaday: How Do You Give A Project Away?

lcr

A few weeks ago, we caught wind of a DIY version of ‘smart tweezers’ from [Kai]’s workbench that are able to measure SMD resistors, caps, and inductors. At that time, [Kai] hadn’t quite finished the software portion of his build, leaving him with a pile of parts and non-working PCBs. The code is finished now, meaning [Kai] has a very capable and very inexpensive version of LCR meter tweezers. He’d like to give back to the open source community and figure out a way to get his tweezers into the hands of makers the world over now. The only problem is he doesn’t know quite how to do that.

We’ve seen smart tweezers before, and they’re still available commercially for about $300. [Kai]’s version brings down the price significantly, so there is a market for these LCR tweezers. The problem, it seems, is getting these tweezers manufactured.

We’re assuming that soldering hundreds of thousand of SMD parts isn’t what [Kai] thinks is a good time; this leaves a Kickstarter as a non-starter, unless he can contract out the manufacturing. Seeed Studio might be a good place for [Kai] to sell his wares, but we’re wondering what Hackaday readers would do in [Kai]’s situation. Obviously he deserves to compensated for his work either through licensing or royalties, but as far as actual advice and recommendations we’re turning to Hackaday readers.

DIY SMD Stencils Made With A Craft Cutter

Unless you’d like to spend hours with a toothpick and a tub of solder paste, stencils are the way to go whenever you’re placing SMD parts. While most commercial and industrial SMD stencils are made out of laser cut stainless steel, [Peter] figured out a piece of plastic and a $300 craft cutter is equally well suited for the job.

[Peter] has spent some time making SMD stencils out of polyester film in the form of overhead transparency sheets. This turned out to be a wonderful material; it’s dimensionally stable, commonly available, and just the right thickness suggested for SMD stencils. The polyester film was cut on a Silhouette Cameo, basically a desktop-sized vinyl cutter aimed at the craft market.

Stock, the Silhouette Cameo rounds off corners, not something [Peter] wanted with features only fractions of a millimeter. He came up with a tool to convert the paste layer of a Gerber file into separately drawn line segments, allowing him to cut SMD stencils for 0.3 mm pitch components.

It’s a great piece of work to make very fine pitch stencils, but we’re wondering if this tool could be used on the much less expensive Cricut paper and vinyl cutter that is unfortunately locked down with some very restrictive software.

Router Jig For A Perfect Circle

router-jig-for-cutting-circles

We once enlisted a contractor to cut a plywood circle for a cat condo we were building. Now we’re embarrassed that we couldn’t come up with a solution as eloquent and easy to use as this circle cutting router jig which [Grays42] built.

He’s using a small trim router for the job. The jig is made up of two thick-walled pieces of PVC pipe. We don’t think the router is attached to jig. Instead you hold it against the wooden spacer which is on the outside edge of the cut. He doesn’t mention how he made the spacers, but we’d recommend cutting a hole the size of the pipes and then ripping down the middle to remove some of the material (tape the two spacers together during fabrication to ensure proper alignment). It just takes some nuts and bolts from the hardware store to assemble everything.

[Grays42] is using this to cut rings for his telescope build. We have our eye on it for making our own wooden Bulbdial clock.

[via Reddit]

Mains Rated Solid State Relay Test Box

building-a-mains-solid-state-relay-test-box

We like our nice, safe, 5V prototyping projects where the only thing that might get fried is a chip. But there are times when you want to switch appliances for one reason or another and then you’re going to want a mains rated relay. [Viktor] got tired of having exposed high voltage on the bench during the prototyping stage of these projects so he recently built a solid state relay test box.

The only thing he bought for the project was the SSR itself. To act as an enclosure he used the brick from an old laptop power supply. This is perfect for a couple of reasons. First off, it’s designed to contain high voltage if there is ever a short or other problem. Second, it’s already setup for incoming and outgoing power. He just needed to remove the guts and mount the relay. Notice that it comes with a clear plastic shield that physically separates the high voltage side from the low voltage control end. This, along with the cable routing, keeps the dangerous stuff on one side to ensure you won’t get an arc to the low voltage portion of the project.