Sunday, April 20, 2014

MakerBot Replicator 2

A couple of years ago, MakerBot took a turn from making 3D printer kits and printers that looked like kits, to "mature products". It introduced the Replicator 2 in 2012, as their first real attempt to make a salable consumer product - for about $2200. The Replicator 2 got rave reviews and seemed to spark the market for "pro-sumer" devices, as the number of competitors seems to have swollen in the meantime. And this new class of devices has now found their way into homes and schools everywhere.

This year, MakerBot introduced their latest "5th generation" products, and the price for the Replicator 2 dropped to $1899 - too cheap to ignore. So I went to the Microsoft Store and grabbed one. Set it up, pushed some buttons, and it's very easy to get started - really impressive how easy it is to get started. I printed a couple sets of the nuts and bolts on the provided SD card. Piece of cake.

But there are nuances and issues. My idea is to teach a technology class as an art (architecture) class, so I tested the printer by printing a model of the house, and the steep, curvy contours of the landscape made a giant mess - the extruder never stops extruding, and drags a thread of plastic every time it has to "cross a valley", thus filling the valley. After the printer finished, I had to go back and clear out these threads, leaving lots of funny edges and bumps.

There is also an on-going balancing act going on in the hobbyist community between getting the plastic to adhere to the build plate during the printing process, and releasing the printed object when finished. It involves: blue painter's tape, kapton tape, isopropyl alcohol, acetone, hair spray, glue sticks and other household cleaners and chemicals - or some combination thereof. The basic process I've started with is to lay down blue painter's tape on the build plate (made of acrylic), and clean it with the alcohol between renderings.

The other battle going on is a search for a solution to the curling of the plastic as it cools. The nuts and bolts are about 3/4" in diameter, and I had no problem printing them directly on the build plate. When I first tried a larger print (4-in square base) without the tape, the plastic peeled up at the corners, and began rocking back and forth as the extruder crossed the area. The tape does not prevent the curling, but seems to keep the print job in place, holding the edges steady to get a better render.

I've also found that by turning the model in the software, you can get the extruder to cross the "valleys" in different ways, so it's worth checking the "print preview" to see which position gives the cleanest render.

Any way, there is much more "art" to this process than it might seem. Regardless, it's an amazing technology.

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