DIY SMD Stencils Made With A Craft Cutter

December 27, 2012 by Brian Benchoff 44 Comments

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

December 25, 2012 by Mike Szczys 36 Comments

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

December 20, 2012 by Mike Szczys 30 Comments

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.

Automated PCB Panelization

December 17, 2012 by Brian Benchoff 13 Comments

panel

Some PCB production houses – Seeed Studio and itead studio, especially – allow you to upload a gerber file and receive a printed circuit board very inexpensively. The pricing structure for these board houses is based on predesignated board sizes – 5cm square or 5×10 cm – and sometimes a project is just too small to justify buying a full 25 square centimeters of board. This is where panelizing comes in: by putting multiple copies of a circuit board on one of the available sizes you can get more boards for the same amount of money. But how to panelize your boards without the (sometimes) hassle of cutting and pasting?

[Martin] came up with a way of panelizing PCBs with just a Python script. By creating one copy of a circuit board in KiCAD, he can fire up his script and tell the computer exactly how to duplicate his circuit to fit any size board.

By his own admission, [Martin]’s script is still a little clunky, but it does allow him to edit the panelized board in KiCAD and also copies the nets so the ratsnest doesn’t go between boards.

Adventures In Mold Making And Making Your Own Enclosures

December 15, 2012 by Brian Benchoff 16 Comments

case

The folks at SC-3000 survivors have been working on a cartridge capable of storing dozens of games for the ancient Sega SC-3000 computer. The PCB works beautifully, but making a case for their cartridge left them with few options. They could use a 3D printer or simply collect a whole bunch of used cartridge cases, but making their own mold for a cartridge case was the best solution.

To create the mold for their multicart enclosure, the SC-3000 survivors first took an old, used case and made a silicone mold. While the first attempt at mold making was encouraging, several problems began to crop up due to the lack of vent holes and wiggling the mold before the resin had set. Before long, a proper technique to make resin casts was developed: use lots of resin, and don’t apply pressure or rubber bands to a curing mold.

We’re always impressed by what can be done with a few sheets of plastic, some Bondo, and the inordinate amounts of patience and sandpaper we see with other case mods and enclosure builds. the SC-3000 survivors put together an enclosure that rivals any Bondo build, and we’re happy they put out this tutorial.

Converting A Chinese Laser Cutter To Work With Mach3

December 13, 2012 by Brian Benchoff 38 Comments

laser

Like most of us, [Chris] has pined over the very, very inexpensive Chinese laser cutters available on eBay for a while now. When most of us disregarded these machines due to their inability to work with the file formats commonly used with laser cutters, [Chris] took the plunge. He was a might disappointed the included software didn’t allow him to use his machine with Mach3 CNC software, so he replaced the included electronics board with one of his own design, giving him all the features of a more expensive laser cutter at a low, low Chinese eBay auction price.

The laser cutter [Chris] bought came with the moshidraw software and controller board that according to one auction can only use BMP, JPEG, WMF, EMF, and PLT files.Wanting a board that can use more common file formats such as PDF and DWG, [Chris] built his own board to communicate with his Mach3 software.

From what we can tell, the new board works with off-the-shelf Pololu stepper drivers and is a complete drop in replacement for the moshidraw board. He’s still finalizing the design, but when the layout, BOM, and schematic are finalized, [Chris] will be putting the files up for everyone to copy. Wonderful piece of work, [Chris].

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Backyard Zamboni Keeps The Best Diy Ice Rink In Town

December 6, 2012 by Mike Szczys 15 Comments

backyard-zamboni

We’ve known people to put down a small ice rink in their back yard during the winter. But a machine to resurface these diy rinks is unheard of until now. The big name in rink resurfacing is Zamboni, the person who invented this method of keeping the ice pristine.

This has almost everything you would find on a commercial model. The tires are studded with stainless steel screws for traction. The riding lawnmower has had its grass cutting blades replaced with a single steel blade that skims the surface of the ice. There’s even a tank of water which is distributed by a copper pipe with many holes and a squeegee which drags behind the machine. The only thing this is missing is a collection system for the slush which is generated by that skimmer blade. But as you can see in the clip after the break, it does just fine without it.

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