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Now you can 3D print this incredible multi-limbed robot at home
Posted by 3DP4E

By Alec | 3Ders

While 3D printing can be called a futuristic, revolutionary, potentially life-saving technology that is set to reinvigorate medical and aerospace industries (which it is), it is also a fun manufacturing technology to use in the comfort of your own home. And if you’re going to play around with a futuristic and creative manufacturing technology, then a robot should be somewhere on the top of your list of 3D printing projects. After all, what better captures the technology’s character?

Now there are a multitude of 3D printable robot projects out there, and we’ve reported on some of the more fun ones out there. But if you’re looking for a real challenge, why not 3D print and assemble a truly functional robot? I’m not talking about a little machine that can walk by itself or blink its eyes, but a functioning robot arm that you would find in a factory slotting car parts into place. For that is absolutely possible to recreate, as Andreas Hölldorfer has been doing in recent weeks.

As the photos illustrate, Andreas has been working on a multi-limbed gripping robot arm on a rotary plate, that can be easily controlled by the user and can move in any direction. It’s an industrial robot in every sense of the word, except that it’s made of plastic. Rather than car parts, it is capable of holding a cup of coffee, which says enough about its strength, stability, and sturdiness (though perhaps not its usefulness). And you can build it yourself, too! His project is still ongoing and needs some refining, but it has reached the stage where it is actually working and Andreas has therefore graciously shared his various designs for the various limbs.

As he explained on his blog and in his various YouTube clips, he was inspired by large industrial-style robots with a real purpose, and decided to just build a 3D printed version of his own. The arm consists of several joints and a gripper, all of which have been printed in ABS – more than 1.2 kg of the stuff! And printing these parts took him about a week. They have been designed and printed with about 12% infill, using the honeycomb infill from slic3r. This did meant some warping was a problem, but it's a WIP model after all. All of it has been printed on his home-made Delta 3D Printer that he recently pieced together himself (for designs and progress, check out Andreas’s blog here). However, most printers should have a print bed that is perfectly capable handling all the files necessary for this robot arm.

If you’re itching to get started yourself, you can find the Thingiverse pages for the various elements here: the basic arm, the forearm, and the rotary plate. The only thing he hasn’t uploaded are the files for the gripper itself, which were based on a design by MSI tech.

Just a word of warning should you like to try this project: not only is it extensive, complicated and time-consuming, it will require a lot of different parts that need to be assembled without a tutorial. While Andreas does explain the basic functions and problems facing every section of the arm, you will need a bit of engineering experience to recreate all the steps at home. Nonetheless, this does make it a challenging and fun project for everyone looking to take their tinkering to the next level.

Its level of complexity is perhaps best captured in the two colors: blue and orange. While the first iteration of the robot arm was entirely blue, the sheer size and weight meant that Andreas needed to redesign some parts. For the first prototype relied entirely on stepper motors, these were unable to effectively handle the entire load and not spill coffee on you.

As he explained in a video, Andreas was therefore forced to split the arm into halves: a blue section powered by stepper motors, and an orange one relying on DC motors, severely complicating the whole design. ‘ One problem with the DC motors is that they are not controlled, so I’ll need encoders to measure the angle of the robot arm. I’ve tried magnet encoders and was very happy with them, and will place them on every joint [and some other locations]. With them, you can absolutely measure the position of the robot arm. The DC gear motors are lighter and provide more torque, but have the drawback that they are not as easy to control as easy as stepper motors.’

While the project is thus still not entirely finished, it's a shaping up to be one of the coolest and most complex 3D printed robotic contraptions we’ve seen in a long time. It will be very interesting to see what it’s capable of once its finished. Check it out!


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