SCARA arm 3D printer

scara-3d-printer

[Quentin Harley] must really have wanted to test his snuff when it comes to mechanical engineering. He’s been hard at work for a couple of years now designing his own SCARA arm 3D printer. That link leads to a recent summary article in which he shows off the build as seen above. It’s not fully functional yet, but he’s at the point where it’s time to develop the driver circuitry and firmware so he’s close. His blog is dedicated to this single project so click around and see what he went through along the journey.

The SCARA arm is seen in blue, using a couple of stepper motors to move the extruder mount along the x and y axes. The bed itself moves along the Z axis via two precision rods with a threaded rod in the center. As you can see, some of the parts are made of wood, and he used PVC for the cross supports between the upper and lower base platforms. But the majority of the build uses 3D printed parts, including the arms, drive gears, and mounting brackets.

[Thanks Peter]

Build a bioprinter from very old inkjet cartridges

bioprinting

This column of messages was printed with Escherichia coli. That’s the bacteria better known as E. coli which can cause so many problems if it makes its way into our food. But the relative size and the fact that this strain was engineered to glow in the dark makes it a perfect candidate for Bio Printing. We find it even more interesting that it was printed using hacked inkjet and computer parts.

There are legitimate uses for this type of technology. But this project is aimed more at getting the word out about the method and how easy it can be. For us, it’s the close look at modern inkjet print heads that was the most interesting. It turns out that common cartridges have an overly high-resolution for this to work well. In order to get so many dots in such a small area the nozzle openings end up being too small for most biological material to fit through. There is also an issue with a filter built into the silicone technology inside.

The solution was to use the InkShield to drive cartridges from very old printers. This lets the team command the cartridge with an Arduino, making it dead simple to tweak the way the material is deposited. They mounted the cartridge holder (using decades-old technology in the form of HP Deskjet 500 cartridges) on the sled of an optical drive and went from there.

Take a glance at the printer in action in the clip after the break.

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An even more useless machine

Useless

Here’s the most useless machine we’ve seen so far. It comes from the workshop of [forn4x] and happily turns itself off whenever any one of its eight switches are flicked to the on position.

The build began when [forn]‘s Canon 850i printer gave up the ghost because of a broken print head. All the other electronics and mechanics were still salvageable, so it was decided to turn this printer into something a little more useless.

The printer used a regular DC motor with an optical encoder to move the print head. [forn] easily found the schematics for this optical sensor, because of the TTL output was able to read out the position of the slider. The rest of the build is an ATMega8, a servo, and an octet of toggle switches. [forn] has been able to get the accuracy of the servo-controlled arm down to about 0.1 mm, more than enough to accurately turn all its switches off.

You can see [forn]‘s most useless machine in action after the break.

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Party photo printer built around a Raspberry Pi

We think [Brian Delacruz] latched on to a good idea with this photo printer project. Instead of building a big photo booth for his party he developed a Raspberry Pi based WiFi photo printer. Right now it’s a prototype that lacks the kind of polish necessary to make a true user-friendly device. But the idea is solid and just waiting for you to improve upon it.

In addition to the RPi he’s using a quality photo printer and a small wireless router. The router simply provides WiFi capabilities for the RPi which is running a web server, mySQL, and FTP. This provides a wide range of upload options which he can work with. Watch the video after the break to see him print a smart phone photo wirelessly.

This can be simplified by using a package like hostapd to use a USB WiFi dongle as an access point. Or if the venue already has Internet access a server could be set up with a QR code to guide people to it. The party starts off with an empty bulletin board and guests would be invited to print and hang their own photos which will go into the host’s guest book/scrap book to remember the event.

[Woz] prints and spend his own $2 bills

[Steve Wozniak's] damn the man, devil may care attitude continues to show with this recent interview. Here he shows off the pad of $2 bills he had made up. He’ll sell one sheet of them to you for $5. Do you think that’s a scam? He say’s “you’d be an idiot not to buy it for five bucks” and after we dug a little deeper, he’s right.

Now, you really need to watch the video after the break before you read the rest of this feature. Trust us, it’s extremely entertaining. [Woz] mentions that he hired a local printer to make the pads for him, but he got the paper from a high-quality print shop. They meet the specs of the federal government and by law they’re legal tender. Each pad has a page of four bills which can be torn off of the gummed top, and there are perforations between each bill for easy separation.

Nothing illegal is going on here. We followed one of the YouTube commentor’s links to this article [Woz] wrote about his $2 bill exploits. The high-quality printer he buys the paper from is the Bureau of Printing and Engraving. He buys the bills in sheets and pays a premium for that option. Each $2 bill costs him $3. But the fun he’s had over the years is probably worth it.

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Tearing through floppy drives to build a small-format dot matrix printer

The accuracy which [Mario] achieved in his pen plotter dot matrix printer is very remarkable. He tore through a pile of floppy drives to get the parts he wanted, and chose to go with a fine-point Sharpie marker as a print head. In the video after the break he flatters us with a printout of the Hackaday logo, but you also get a look at one problem with the build. The ink doesn’t always flow from the felt tip and he has to coax it (almost like priming a pump) with a piece of scrap paper.

He was inspired by the pen printer we featured back in June. This rendition features a printing area of 1.5×1.5 inches that can accommodate 120×120 black and white pixels. He’s not a microcontroller type of guy and is driving the printer from the parallel port of his computer.

The best printing technique puts the pen down and moves it around just a bit (helps prevent the ink flow problem we mentioned earlier) and produces images like one in the lower right. We love the 8-bit nature of the result and would use this all the time to make our own greeting cards.

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Self-feeding pen printer

At first look we thought this was a plotter, but it’s really more of a dot matrix (or line matrix) printer. [Bruno] whipped this up using parts from a DVD optical drive. It is capable of moving the pen along the Z and X axes, and feeding the paper along the Y axis.

The video after the break shows the machine printing Megaman, an image perfectly suited to the low-resolution pixels this can put out. But even without the high-pixel counts you might get from a thermal printer, we just love the look of this one. And who doesn’t have an optical drive sitting around just waiting to be hacked? It looks like the one part you’re going to have to source is the stepper motor and geared feed wheel that moves the paper.

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