Improvised Metal Lathe

[McKGyver] needed a few parts manufactured. Instead of going the normal route – finding friends with machine tools or paying a machine shop, he improvised a rudimentary metal lathe.

As much as we love 3D printers, they’re not the be-all, end-all solution for everything. Sometimes, you need to get a little dirty and do it the old-fashioned way. [McKGyver] needed a way to produce aluminum shaft couplers to join stepper motors to lead screws. A 1940s grinding wheel was used for the headstock. Since [McKGyver] only needed couplers of one size, he made a jig out of wood to attach the aluminum blanks to the spindle. A drill and a focuser from a photographic enlarger makes up the tailstock of the improvised lathe. The use of a camera focuser is pretty clever. Unless the equipment has been damaged, it’s guaranteed to move in a straight line. A small laser was used to align the drill.

The finished couplers were concentric to 0.005″. A ‘passable precision’ for his application, and a clever build that doesn’t involve moving a thousand pound South Bend lathe.

Freakin’ Huge CNC Router

[Tom] sent in a gigantic 3-axis router that he pieced together during a 2 week-long work experience placement. Looking at this picture showing a 12-inch ruler on the work area, we realized that this may be the largest CNC router we’ve seen on Hack A Day.

[Tom]’s employer gave him some obsolete axes, so piecing the mechanical components together was very easy. The only real problem was interfacing the CNC controller to a computer. This meant [Tom] had to convert G Code to the code used by the antiquated NSK axes. Where G Code defines arcs with a start point, end point, and radius, the NSK code defines arcs with a start point, end point, and another point along the arc. It’s a tricky bit of math, but [Tom] built some software that did this in Visual Basic.

Right now, [Tom] only has a pen tool attached to the router; you can check that in action after the break. We’re trying to imagine what we would do with a 4 m² work area; this could easily be used to make a giant reprap or other 3D printer.

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Selective Solar Sintering With Sand

[Markus Kayser] built an amazing solar powered SLS printer, but instead of using lasers and powdered plastics his machine uses the power of the sun to heat sand into complex shapes.

[Markus]’ printer uses the same concept as his earlier solar cutter – burning things with a magnifying glass. Interestingly, the printer isn’t controlled with stepper motors and reprap electronics – it’s completely cam driven. The solar panels only power the motor attached to the frame moving on bearings made from skateboard wheels.

We’d guess that [Markus] is using a little more than 2 square meters of Fresnel lenses in his project. Since solar irradiance is about 120 W/m² (PDF warning), [Markus] is concentrating a lot of energy onto a point the size of a quarter, which would be necessary to heat up sand to its 1500° C melting point. The resolution isn’t what you could get with a laser, but [Markus] was able to print an amazing bowl along with other complex 3d shapes.

Check out [Markus]’ video of the solar sinter printer after the break. There’s also a video of his previous experiment with the solar cutter.

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Snap-together PCB Mill

[Jonathan Ward] came up with the MTM Snap, a snap-together pcb mill as part of the Machines That Make group at MIT.

We covered [Jonathan]‘s previous work made out of half-inch plywood, but the new iteration of his PCB includes a clever snap-together mechanism instead of screws and bolts. Although the MTM Snap looks a lot like3d printers such as a reprap, the similarities end with the off-the-shelf stepper motors. Instead of using motor drivers and control electronics from a reprap, the project uses custom stepper drivers, controlled by a bare Arduino.

We’re really impressed with the results of the MTM Snap compared with what is possible on a reprap-derived milling machine like a makerbot or wolfstrap. We’re thinking that’s due to the mass of this project compared to the printed ABS parts of the ‘common’ 3d printers, but any MEs are more than happy to correct that notion.

Check out the video after the break to see the machine in action and a great view of the snap-fit mechanism.

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A Keygen For The Real World

key_generator

[Nirav] found that he rarely printed anything useful with his RepRap, so to shake things up, he decided he needed to work on a project that didn’t involve printing yet more RepRap parts.

The goal of his project was to create working replicas of house keys by simply using the code imprinted at the factory. He purchased a handful of used lock sets from eBay, then carefully measured the keys with a ruler and calipers to get the blank dimensions just right. After that was done, he looked around online and was eventually able to create an OpenSCAD model using a chart of pin depth specifications he located. By changing the last line in the model’s code he can print any coded key. For keys lacking a code, he can manually measure the height of each bit and print replicas that way as well. Once printed, he says that they keys are strong enough to turn most locks he has come across, including deadbolts.

This is undoubtedly a neat project in its own right, though we would be interested to see if someone could get it paired with a program like SNEAKEY to generate bit measurements by sight alone.

Print Your Own Header Shrouds

Don’t get us wrong, printable whistles are cool and all, but these printable header shrouds make us think that filament printers like the Makerbot and RepRap might just be worth their salt. This utilitarian purpose is a departure from the souvenirs, toys, and art that we’re used to seeing from the expensive development toys tools.

The six and ten pin header shrouds are designed for a snug fit that makes it easy to glue them onto the plastic spacers of male pin headers. We use IDC plugs and ribbon cable all the time in our projects, but never seem to order shrouded connectors; this is perfect for us. It makes us wonder what other PCB-friendly printable designs we’ve been missing out on? Surely someone’s been printing stand-offs with threaded inserts, right? If you know of something useful that we can share with the rest of the readers, don’t hesitate to send in a tip.

[via Dangerous Prototypes]

Molded Parts: Prusa Mendel In 30 Minutes

This set of white RepRap parts were created in molds, instead of being printed by another RepRap. [Mark A. Ganter] of the University of Washington admits that this breaks the idea of a 3D printer that is self-replicating. But the molds – which were created by tweaking Prusa Mendel parts to be mold friendly – have the ability to produce every plastic part necessary to build your own RepRap and they can do it much faster. Once the molds were completed [Mark] and his students were able to produce a full set of parts in just 30 minutes, cutting as much as 14 hours off of the time it would have taken to print the parts. Still not convinced? How about this: the molds can be created by a 3D printer or by using a high-resolution power printing method like they have here.

The process starts by printing master parts, then creating a silicone RTV mold from them. Once the molds are ready, [Mark’s] team pours polyurethane into them and waits for it to harden. They plan to share the STL files in less than a week so that you can make your own molds to use to build your RepRap army.