Milling A Flow Sensor To Safeguard A Laser Tube

Powerful lasers get powerfully hot and if you don’t keep them cool you’ll pay the price. After two such experiences [NixieGuy] got smart and milled this flow sensor as a failsafe.

Laser cutters are awesome. But acquiring one can be expensive, and keeping them in working order is no small feat. From the gunk that builds up as a byproduct of vaporizing the cutting stock, to keeping the optics focused correctly, it’s a game that forces you to become a laser cutter operator and not merely a user. One of the worst things to deal with is having to replace a burnt out laser tube. They do have a life to them but in this case the filter on the water cooling system clogged and the tube cooked itself. Twice.

Flow sensor shown in the upper right.

This flow sensor now acts as an interconnect with the laser enable line. Starting with an acrylic rod, [NixieGuy] machined out a center hole for a magnetic stopper, then milled three channels for water to pass around it. Each end of the rod was turned on a lathe to interface with plastic tubing of the water cooling system, and a slot was milled on the outside for a reed switch.

The demo video is below. You can see that when water flows it pushes the magnetic stop up (against gravity) where it engages the reed switch, allowing the laser to operate. If something impedes the flow of water (even if the pump still runs) the laser will be disabled and (hopefully) prevent future tube loss.

Want to see some of the oops moments faced by many a laser cutter operator? Check our guide on how to fail at laser cutting.

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Your Work Won’t Move With A Magnetic Drill Press Vise

Setting up your workpiece is often the hardest part of any machining operation. The goal is to secure the workpiece so it can’t move during machining in such a way that nothing gets in the way of the tooling. Magnetic chucks are a great choice for securely and flexibly holding down workpieces, as this simple shop-built electromagnetic vise shows.

It looks like [Make It Extreme] learned a thing or two about converting microwave oven transformers to electromagnets when they built a material handling crane for the shop. Their magnetic vise, designed for a drill press but probably a great choice for securing work to a milling machine, grinder, or even a CNC router, has a simple but sturdy steel frame. Two separate platforms slide on the bed of the vise, each containing two decapitated MOTs. Wired to mains power separately for selective control and potted in epoxy, the magnets really seem to do the job. The video below shows a very thick piece of steel plate cantilevered out over one magnet while having a hole cut; that’s a lot of down force, but the workpiece doesn’t move.

Like the idea of a shop-made vise but would rather go the old-fashioned way? Check out [Make It Extreme]’s laminated bench vise, which also makes an appearance in this video.

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Drill Press To Mill Conversion

Every time we look at the little short Z axis of our CNC mill, we think about converting a drill press to a mill. In theory, it seems like it ought to be easy, but we never quite get around to it. [AvE] did get around to it and made his usual entertaining video about it that you can see below. If you haven’t seen any of [AvE’s] videos before, be warned: there is a little colorful language in a spot or two.

This isn’t a CNC mill, by the way, although we suspect you could convert it. Essentially, he adds a spindle and an XY table to a Ryobi drill press. It sounds simple, but getting everything to work did take a few tricks, including a blow torch.

Actually, turns out the blow torch didn’t really do it, but we won’t spoil the final resolution to the problem. Once it was resolved, though, he did manage to do some actual milling, accompanied by some music we wouldn’t associate with [AvE].

Although billed as a “poor man’s” build, the XY table alone was about $200. So add in the cost of the drill press, the spindle, and the mill and this is still a fair chunk of cash. We’d love to see it compared to a Harbor Freight milling vise. We suspect the Harbor Freight vise might not be as good, but is the difference worth the $130 difference in price?

We’ve seen this kind of conversion done before without the colorful language. If you do this conversion and want some practice, why not build a magnetic carabiner?

Home Built PCB Mill Reportedly Doesn’t Suck

It’s 2017, and getting a PCB professionally made is cheaper and easier than ever. However, unless you’re lucky enough to be in Shenzhen, you might find it difficult to get them quickly, due to the vagaries of international shipping. Whether you want to iterate quickly on designs, or just have the convenience of speed, it can be useful to be able to make your own PCBs at home. [Timo Birnschein] had just such a desire and set about building a PCB mill that doesn’t suck.

It might sound obvious, but it bears thinking about — if you know you’re incapable of building a good PCB mill in a reasonable period of time, you might save yourself a lot of pain and lost weekends by just ordering PCBs elsewhere. [Timo] was fairly confident however that the build would be able to churn out some usable boards, however, and got to work.

The build is meant to be accessible to the average hacker who wants one. The laser cut & 3D printed parts are readily available these days thanks to online services that can manufacture for those who don’t have the machines at home. [Timo] uses a rotary multitool for a spindle, a common choice for a budget CNC build.

With the hardware complete, [Timo] has spent time working on optimising the software side of things. Through careful optimisation of the G-Code, [Timo] has been able to improve performance and reduce stress on the tooling. It’s not enough to just build a good mill — you’ve got to have your G-Code squared away as well.

Overall, the results speak for themselves. The boards don’t suck; the mill can do traces down to 8 mil, and even drill the holes. We’d love to have one on the workbench when busting out some quick prototypes. For another take on the home-built PCB mill, why not check out this snap-together version?

Need An Enclosure? Try Scrap Wood With Toner Transfer Labels

This utilitarian-looking device takes an unusual approach to a problem that many projects face: enclosures. [Jan Mrázek] created a device he calls the Morse Thing for a special night’s event and used what appears to be a humble two-by-four plank for the enclosure. The device is a simple puzzle using Morse code and was intended to be mounted to a railing, so [Jan] milled out the necessary spaces and holes for the LCD and buttons then applied labels directly to the wood via toner transfer – a method commonly used for making PCBs but also useful to create clean, sharp labels.

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Tips For Buying Your First Milling Machine

If you’re interested in making things (and since you’re reading this, we’re going to assume you are), you’ve almost certainly felt a desire to make metal parts. 3D printers are great, but have a lot of drawbacks: limited material options, lack of precision, and long printing times. If you want metal parts that adhere to even moderately tight tolerances, a milling machine is your only practical option. There is, after all, a very good reason that they’re essential to manufacturing.

However, it can be difficult to know where to start for the hobbyist who doesn’t have machining experience. What kind of milling machine should you get? Should you buy new or used? What the heck is 3-phase power, and can you get it? These questions, among many others, can be positively overwhelming to the uninitiated. Luckily, we — your friends at Hackaday — are here to help give you some direction. So, if you’re ready to learn, then read on! Already an expert? Leave some tips of your own in the comments!

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Glue Your Sumo Robot To The Mat With Custom Sticky Tires

Mini Sumo seems like one of those hobbies that starts out innocently enough, and ends up with a special room in the house dedicated to it. One day you’re excitedly opening up your first Basic Stamp kit, and the next you’re milling out mini molds on a mini lathe to make mini extra sticky tires.

[Dave] started out trying to find a part from the local big box store that was just a little bigger than the wheel he wanted to rubberize. He set the wheel inside a plumbing cap and poured the urethane in. It worked, but it required a lot of time with a sharp knife to carve away the excess rubber.

In the meantime he acquired a Sherline Mini Mill and Lathe. With the new tools available to him, he made a new mold out of a bit of purple UHMW and some acrylic. This one produced much nicer results. Using a syringe he squeezed resin into the mold through a hole in the acrylic. Much less cleanup was needed.

He later applied these methods to smaller, wider wheels as his mini sumo addiction took a stronger hold on his life.