Welding And Casting ABS

Anybody who has a 3D printer always has a ton of useless plastic lying around. Some of that plastic may be from useless baubles, but most of it is in bad prints, short bits of filament, and general scraps. [Luke] found an interesting way to put those ABS scraps to use, and ended up turning trash into valuable plastic parts.

Commonly sold as nail polish remover, acetone will turn anything made out of ABS into a puddle of plastic. [Luke] makes glue using the same process – he fills a small container half full of acetone and half with small bits of ABS. After a day or so, he has a nice thin glue that dries into solid ABS. [Luke] used this to create a 400mm long piece of extruded t-slot. We don’t know if it would be suitable to build a child RepRap from, but it would sure be an interesting experiment.

[Luke] also did a little bit of casting with his ABS glue. With a thicker solution of ABS and Acetone, he managed to make this ‘thing’. The entire process is explained over at Thingiverse, We can’t wait to see what can be done with this stuff.

The Cheapest And Easiest 3D Printer We’ve Seen So Far

3D printers are awesome, but boy are they frustrating. If you’ve built a RepRap Mendel, Prusa or Huxely, you know there’s nothing quite like trying to get a washer off of a threaded rod without disassembling the entire machine. This frustration in part sourcing, assembling and correctly aligning a printer is where printers like the Makerbot find their niche. There’s a new printer on the block that promises a 45 minute assembly time and less than 2 hours from starting the build to first print. It will do all this for under $500, electronics and motors included.

From the Flickr photoset, we can see that the Printrbot has 2 motors for the z-axis, uses sanguinololu electronics, and uses a derivative of Wade’s extruder – all proven design choices. Unlike the RepRaps, most of the frame is actually printed, and not built out of threaded rods. This drastically reduces the assembly and calibration time.

The inventor of the Printrbot, [Brook Drumm], has a Kickstarter up where he’s selling complete kits (electronics, motors and vitamins) for $499. This beats the very inexpensive SUMPOD in affordability. We haven’t been able to find the 3D design files for the Printrbot (although you can buy these printed parts for $75), and there’s no word on the build volume of the stock printer. That being said, the printrbot does have pretty good resolution. Check out the video of a Printrbot in action after the break.

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A Technique To Avoid Warping On Large 3D Prints

[Jamie Mantzel] figured out his own way of 3D printing large objects without fear of warping. First a bit of background information. When using a 3D extrusion printer like the RepRap or Makerbot, prints that span a large area tend to warp. That’s because these printers lay down one thin layer of plastic at a time. If the first layer cools too much, it will shrink a bit before the next layer is laid down. As that second layer cools it pulls the part toward the center, eventually bowing the part which causes it to hit the extruder head.

After having several prints encounter this issue [Jamie] decided to alter his design so that it wouldn’t cause these stresses. The first thing that he did was to add alternating voids to a layer between the raft and the actual part. You can see these as notches on the bottom the piece pictured above. This takes care of the initial stresses from the first layer. Next, he adds holes wherever he can in the main body of the part. This is especially important on the edges of the piece where the warping forces will be the greatest.

He also moved the starting position of the bed closer to the extruder head. His hope is that this will help the raft bond better, and resist pulling away from the bed during printing.

See his video explanation of his adventure after the break.

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Build Your Own Stereolithographic 3D Printer

[Andy’s] 3D printer build uses lasers to create objects from goo. The Stereolithographic process uses resin that is cured by UV light to create the finished product. A single laser mounted to a CNC gantry is able to precisely target a point on the surface of the resin to begin the printing process. As the layers are built up, the stage, which is mounted on the Z axis, slowly sinks into the resin vat. So basically you’re printing from the bottom up but the laser never moves up or down. There’s a time-compressed video of an object being printed embedded after the break. It illustrates the process better than we can describe it.

We think [Andy] really went all out with his write-up of the build process. The quality he achieves in his prints is quite excellent, but you must consider the cost versus an extrusion-based 3D printer. One liter of the UV resin he prints from can cost over $200.

If this sounds familiar it’s because we got a sneak peek at it back when we looked in on his Delta robot work.

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3D Printed Electromechanical Computer

A few nights ago, [Chris Fenton] was hanging out at NYC Resistor putting in some time on his electromechanical computer project. You might remember [Chris] from his tiny Cray that he’s putting an OS on. It seems [Chris] is going back in time about 150 years and has set his sights on a 3D printed version of [Babbage]’s Analytical Engine.

The Analytical Engine was is a remarkable feat of engineering and machining. It was the first programmable computer. Shame, then, that it was never built in the 1800s. [Chris] isn’t building a glorified calculator like [Babbage]’s polynomial-computing Difference Engine – he’s going all out and building something with conditional looping.

[Chris] calls his device an electromechanical computer, so we’re assuming it won’t be crank driven like the version in the British Science Museum. Right now, he’s constructed the decade-counting gears that are vitally important for the ALU of his design. All the parts were printed on a Thingomatic, so we’re betting [Chris] is going to be relying heavily on the MakerBot automated build platform for the thousands of parts he’ll have to fabricate.

Check out the video from NYC Resistor after the break.
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14-part RepRap Saga Draws To A Close

Behold, another RepRap springs into existence! Well, springs might not be the best choice of words, it took a while and there were many bumps in the road. But [NBitWonder’s] self-built RepRap is now finished and you can read his 14-part build log to see all that went into the process.

We checked in on the project at one of the early stages. At that point he was just beginning to assemble the hardware and we mused that the calibration stage is where we thought things would get exciting. The project didn’t disappoint, as he had many follies getting the extruder heads to work. At first some issues popped up when figuring out what diameter filament would work for the print head he was using. Once that was worked out, a less-than-precise PID controller led to the clogging and eventual destruction of the extruder tip. He goes on to assemble and test a heated build platform only to discover that the resistors shipped with the hardware are shockingly underrated for the task. We could go on and on, but that would ruin the fun for you. Bookmark this one for the weekend and enjoy!

Multicolor 3D Prints The Hard Way

After drooling over the Makerbot dual-head extruder, [Brett] decided to get off his duff and make a proper multi-color print.

[Brett] has been making a few bottle openers for friends and has been successfully experimenting with switching filaments in the middle of a print. For his “Saturday Killer” bottle opener, he decided to push multicolored prints to the limit. For the “Saturday Killer,” [Brett] decided to print an abridged version of the classic Simpsons quote, “Beer, the cause of, and solution to, all of life’s problems” on the side of a bottle opener in 4 different colors.

The files necessary to print the Saturday Killer were generated in OpenSCAD. The general principle behind the design is to generate separate .STL files for the bottle opener and the sides, split those files into 2-layer chunks, and print those files while constantly adjusting the z-height. It’s not called the Saturday Killer for nothing, so [Brett] had to change the color of his filament 25 times.

A much simpler version of a complex multi-color print is [Brett]’s Shepard Fairey inspired self-portrait. Still, we’re thinking a dual head extruder is somewhere in [Brett]’s future. At least he’s got the technique down.