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.
Here’s a tale that warms our hearts. [Gord] is helping out the local living-history museum by rehabbing a historic woodworking tool that they want to add to their live demo woodshop. It’s a hundred-year-old manual drill press that has seen a ton of use.
There are three things that [Gord] has going for him. First off, the Champion Blower and Forge Co. built them to last. Second, he’s not really working on a deadline; the museum doesn’t need it back until May. And third, [Gord] has the tools he needs to do this right.
After cleaning and blasting [Gord] gets down to the really interesting repairs. First off, it wouldn’t be a drill press if someone hadn’t tried to drill through the table at some point. TIG welding filled it up and some milling brought it back. This same method was used again to make a beautiful custom replacement ACME rod. Throwing in a custom bushing replacement, turned wooden handle, and a several other fabricated parts, and [Gord] had the press working again. Check out the mechanism in the video below that shows the crank action turns the bit and a cam advances it through the work piece.
Continue reading “Rehabbing an Historic Tool from Champion Blower and Forge Co.”
Hobby CNC mills have made rapid prototyping easier and faster for hackers. One really useful application is quickly fabricating your own milled PCB’s. [proto logical] built a Reference PCB Business Card using his CNC mill after repeatedly coming across other hackers who were not too convinced about the capabilities of CNC mills in routing PCB’s (also referred to as isolation milling). He thought of making a business card sized reference PCB to show around when he bumps into such folks.
To keep it useful, he included inch and centimetre scales, 0.1″ grid of holes, reference track widths from 16 mil to 66 mil, a few common drill holes and vias and some SMD foot prints. The single sided board is 50 mil thick, so it doesn’t bulk up his wallet. He’s posted the Eagle board file (direct download) and G-code (text file) for those interested in milling their own reference boards. The idea isn’t new – it’s been tried several times in different form factors in the past, generally using more traditional techniques. [proto logical] got inspiration from [Rohit Gupta’s] TinkerRule – The Maker’s Swiss Army Knife. Then there’s the very popular uRuler made by [Dave Jones] of EEVBlog fame. If you have any suggestions on improving the design, chime in with comments here.
Thanks to [ACG] for sending in this tip that he dug up while looking for CNC routed PCB’s.
There are a few all-in-one CNC/milling/plotting/3D printing/engraving bots out there that claim to be mini factories for hobbyists, prototypers, and other homebrew creators. The latest is Diyouware’s TwinTeeth, a bot obviously inspired by a few 3D printers, but something that has a few interesting features we hope will propagate through the open hardware ecosystem.
The design of the TwinTeeth is an inverse delta bot, kinematically similar to a large number of 3D printers out there. Instead of suspending the tool from a trio of arms, the TwinTeeth puts the work surface on the arms and suspends the tool from the top of the machine. There are a few neat bonuses for this setup – all the tools, from a BluRay laser diode, a Dremel, solder paste dispenser, and a plastic extruder for 3D printing can be mounted in easy to mount adapters. The TwinTooth design uses three locking pins to keep each toolhead in place, and after a little bit of software setup this machine can quickly switch between its various functions.
One very interesting feature of this bot is the ability to mask off PCBs for chemical etching with a BluRay laser diode. This actually works pretty well, as evidenced by the teams earlier work with a purpose-built PCB masker machine. The only problem with this technique is that presensitized boards must be used. If that’s an issue, no problem, just use the Dremel attachment with a v-bit cutter.
Researchers at the Hasso Plattner Institute have created “Scotty,” a so-called teleportation system. While the name is a clear homage to the famous Star Trek character, this is not the Sci-Fi teleporting you may be expecting. The system is composed of two 3D printers (they used a pair of MakerBot Replicators). The “sender” printer has a camera and built-in milling machine. It uses deconstructive scanning – taking the picture of an object’s layer, then grinding that layer down to expose the next layer – and then sends the encrypted data to a “receiver” printer with a RasPi to decrypt the data so that it can immediately print the object. The ultimate idea behind this is that there is only one object at the end of the process.
It’s a disservice describing Scotty as a teleporter. By the researchers’ definition of a teleporter, the lowly fax machine is on par with Scotty – and it doesn’t destroy the original. The researchers claim that this destructive-reconstuctive method preserves the uniqueness of a given object, as long as any sentimentality. We can agree with the unique aspect: the less copies of something means it retains it intrinsic value in the marketplace. The sentimentality – not so much. We’ve all had a moment in our lives where a treasured item of ours, worthless to everyone else, was destroyed. Either we’d get a replacement or someone else would give us one to silence our wailing, but it wasn’t quite the same. If you could clone your dead pet, subconsciously you’d know it’s not going to be the same Fluffy. It’s that exact thing, atoms and all, that has the emotional attachment. Trying to push that psychological perspective onto Scotty’s purpose is irksome.
Continue reading ““Scotty” Is More Hungry 3D-printing Fax Machine than Teleporter”
Breaking a pane of glass in half is easy – just score it, break it, and after practicing a few times, you’ll eventually get it right. What about cuts that are impossible with a normal glass cutter, like radiused corners and holes? For that, you’ll need CNC. Yes, you can cut glass on a CNC machine. All you need is a diamond burr or glass drilling bit, high speeds, low feeds, and lots and lots of coolant.
Cutting glass on a CNC machine doesn’t require any spectacularly specialist equipment. [Peter] is using an $800 Chinese mini CNC engraver for this project, but that’s not the only tool that was required. A fixture for holding a glass plate was also needed, but [Peter] quickly fabricated one out of acrylic.
Cutting glass with a CNC is something we’ve seen before. [Ben Krasnow] has been using diamond burrs, high speeds, low feeds, and lots of coolant to cut mirrors so expensive you don’t even want to guess.
While [Peter] isn’t getting the perfect finish [Ben] got a few years ago, he’s still milling holes and slots in glass. He’s wondering if it could be possible to mill an aspheric lens using this technique and a special spherical burr, something that would be very interesting to see, and could be a pretty good way to rough out telescope blanks.
[Jens] aka [Tumblebeer] has compiled an impressive overview of the Tumblemill, his homemade CNC mill. It warms our hearts to learn that [Tumblebeer] was inspired to pursue electronics by projects featured here on Hackaday, even if it means he dropped out of med school to pursue electrical engineering. We’re glad he’s following his passion, though, and reading through his blog reveals just how far he’s come: from fiery disaster in his first projects to a gradual obsession with making a CNC device, [Tumblebeer] has made plenty of mistakes along the way, but that’s how it should be.
His first iteration was a CNC router that used rubber wheels as linear bearings. It worked…barely. His latest build grew out of meticulous Solidworks modelling, with a moving gantry design constructed largely from aluminum, and upgraded linear motion: this time a bit overkill, using HIWIN HGH20CA blocks. Rather than sourcing a traditional spindle mount, [Tumblebeer] opted for the housing from a LM50UU bearing, which provided both the perfect fit and a sturdier housing for his 2.2kw spindle.
Visit his project blog for the details behind the mill’s construction, including a lengthy installment of upgrades, and hang around for a demo video below, along with the obligatory (and always appreciated) inclusion of the Jolly Wrencher via defacing an Arduino.
Continue reading “The Tumblemill: Homemade CNC Milling”