A six-year adventure into the world of CNC fabrication

Hackaday doesn’t always get the entire back story of a build. The usual assumption is that someone decided to build something, and with just a little bit of effort the project makes it into the Hackaday tip line. This doesn’t do justice to the builder, with skills honed after years of practice and experience. A 200-word summary is deceiving, and makes everything look almost too easy. [Michal] decided to buck that trend and sent in his half-decade long adventure of becoming one of the best micro-scale machinists we’ve ever seen.

In 2006, with years of robots made out of hot glue and cardboard behind him, and the quality of 3D printers not up to his exacting specifications, [Michal] snapped. He sunk the better part of $3000 into a Roland MDX-15 desktop mill. After several months of futzing about with acrylic sheet, [Michal] came across the wonderful machining properties of modeling board.

Determined to do something useful with this modeling board, [Michal] started looking into resin casting. Casting in resin is a common technique in the artist and model maker communities to mass produce small plastic parts. After getting his hands on eight liters of polyurethane resin, [Michal] made a useful part guiding the direction his skill set would grow in the coming years.

After years of experimenting with techniques, materials, and mediums, [Michal] eventually honed his craft and was able to finally start building real robots. These projects were a far cry from the cardboard and milk jug contraptions made earlier in his career. [Michal] was now producing incredibly precise gear assemblies with accuracies within 0.002 mm.

You may remember [Michal] from his robot with pivoting wheels we showcased last week. He got a lot of email from people wanting to know how to start delving into his unique blend of artistry, engineering, and craftsmanship. The good news is you can now learn from his mistakes, so a planetary gearbox shouldn’t take more than a few months to finish.

Wooden CNC touch probe

diy-touch-probe

[Gary] sent a few pictures of his latest project our way via Flickr, which we thought a few of you CNC owners might be interested in. He has been working with his CNC machine a lot lately and decided it was about time he built a touch probe for his rig.

His initial goal was to use the touch probe to ensure his CNC table was perfectly level, but we’re thinking it will be helpful for a lot of different projects in the future. [Gary] says he was really looking to put together a proof of concept device, but that things worked out so well he had to share.

His probe seems to work very well, even without the fit and finish of others we’ve seen in the past. The body of the probe itself was built using several layers of quarter inch plywood, housing three sets of two screws. The screws are wired together in order to form a closed circuit when the brass probe is inserted. When the probe makes contact with a solid object, the circuit is broken, and the coordinates of the probe’s head are recorded.

Though [Gary] admits that he was not super careful when it came to building the probe, we think the results speak for themselves. For a first iteration its scanning abilities are pretty impressive – we can’t wait to see version 2.

CNC'd business cards will definitely get you noticed

cnc-business-card

The guys over at North Street Labs were bored, so they figured why not go ahead and built a CNC machine just for kicks. While they haven’t put up build details on the CNC just yet, they do have some newly milled business cards to show off just how well the machine works.

Part ruler, part LED throwie, we think their new business cards look great. Milled out of thin acrylic sheeting, their cards feature the North Street Labs logo and URL along with 1/32” ruler markings along the top. The card is also fitted with space for a button cell battery and RGB LED, which illuminates the entire card nicely from the side.

They say that the cards take about 5 minutes apiece to make, which is not bad at all. At $0.50 a pop, the cards are not nearly as cheap as those made from cardstock, but when you’re looking to impress what’s a couple of quarters?

Continue reading to see a short video of their CNC-milled business cards in action.

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CNC conversions with [Bob]

[Bob Berg] emailed in to request that we take a look at his website. We did, and we liked what we saw! [Bob] has done a couple CNC mill conversions and documented the process quite thoroughly.

The first one listed on his site is a Sieg x-3, seen above. [Bob] explains that the first thing he did when he received it was tore it apart and  cleaned it meticulously. We’re not sure if [Bob] was being insanely neat, or if he bought a used dirty unit. Either way, you can’t argue that a nice clean machine is the way to start. After a short while using it the way it was, he added a digital read out for a little more accuracy. From there, he went for a fully motorized conversion.

Keep looking around his site. There is another full build (a lather master RF45) as well as some miscellaneous other projects that are quite interesting.

3D printer with insane accuracy uses a DLP projector

After years of work, [Junior Veloso] is finally getting his 3D printer project out to the public. Unlike the Makerbots and repraps we usually see, [Junior]’s printer uses light-curing resin and a DLP projector to build objects with incredibly fine detail.

One highlight of [Junior]’s project is the development of low-cost resins. Normally, light curing resins are extremely expensive, but [Junior] is actively trying to get the price of resin down to $150 USD per kilogram. A quick back-of-the-wolfram calculation tells us you should be able to print about 7-800 cubic centimeters with a kilogram of resin. It’s much more expensive than plastic filament used in other 3D printers, but that’s the price you pay for quality.

There’s a very popular Indiegogo campaign that is trying to raise money to mass produce the resin and some components of this kit. We’re not impressed with the rewards for this campaign – $59 for a .PDF description of the printer without any dimensions, $159 for a BOM, dimensions and the formula to make your own resin, and $400 for the closed-source software [Junior] devleoped – but hopefully this Indiegogo gets cheap resin out onto the market. There’s a short FAQ about this printer, so we’ll leave our readers to tactfully discuss the merits of this printer in the comments below.

You can check out the process of printing a remarkably detailed alien skull in the video after the break.

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A Little Geneva Drive Made of Wood

MDF Geneva drive in action

Long ago, before servo motors and linear actuators were common, clever mechanical devices were what engineers used to produce the needed motion for their processes. The CNC-cut Geneva Drive may not be fit for industrial use, but this type of device has been used in everything from film projectors to rotating assembly tables. The constant rotation of the driving wheel is translated into intermittent motion by the [Maltese cross] driven wheel.

The drive and Maltese cross section of this particular drive are made out of MDF with the exception of a putty material that the motor shaft press-fits into. The article claims that this is the only Geneva drive in existence made out of MDF, however, we’d love to see that proven wrong in the comments!

If you’d like to make one of these yourself, CAD and G-code files are given for the hand-cranked version that this Drive is based off of in a separate post.  If you’re not familiar with how a drive like this works, or would just like to see everything in action, be sure to check out the video of it after the break! [Read more…]