MakerBot Industries

3D Printable Mousetrap Car Parts by Tesla893

How awesome is this printable mousetrap car by tesla893? ¹  In my high school physics class I had to design a mouse trap car and a balsa wood bridge.  The car that ran the farthest and the bridge that could hold the most weight won.  If you think about it, those challenges are really just design challenges – not construction tests.  Why should the quality of your ideas be constrained to the steadiness of your hand?  Imagine if the bridge test were instead “design the strongest bridge using only 1cc of plastic.”

And, there’s so many other ways to take this design.  You could install a mouse trap power engine into a Lamborghini, Mini Cooper, or other nifty car already on Thingiverse.  Better yet, someone could design a printable mouse trap to go with the mouse trap powered vehicle.  How cool would that be?  It could capture the mouse and take it outside for you all at once!

1. It looks like this is the second mousetrap powered vehicle on Thingiverse after Dustynrobot’s car about four months ago, but the first printable one. [↩]

Thing-A-Day.com!

The website Thing-A-Day.com challenges people to create a new thing each day in February.  Sign-ups start on January 21, 2011 and end on midnight of February 1, 2011.

And the timing really couldn’t be better.  Now that Thingiverse has incorporated Flattr buttons, people can even reward you with “digital tips” to help keep you motivated throughout the month.  So, dust off some old designs, get inspired to create new things, sculpt something amazing on 3Dtin.com, and share it with everyone!

Retroacan_004 by sergio.carrasco.a on 3DTin.com

3Dtin.com is an online 3D design program.  Imagine someone stirring up Sketchup, Legos, and playdoh in a big pot and then sticking it up on a web page for all to use.  The web interface is very intuitive and the mix of colors plus solid building block modeling system makes for a fun way to quickly mock up a design.  Although, the objects that you can create are highly “voxelated” (Read: blocky) an unbounded building system like this is really only limited by your imagination.

Solder Holder by pehr

Last, but not least, Thingiverse citizen pehr put together a Solder Holder by designing in 3Dtin and then exporting directly to an STL!

One of the more frequent questions people would ask us at CES was “what’s the difference between a Thing-O-Matic and a Cupcake?” We’d tell them about the improved Z stage travel, microstepping, mechanical endstops, etc. but sometimes it’s easier to show than tell:

Thing-O-Matic on top, Cupcake below.

Plastruder base top plate - with ooze!

Yesterday I tried to print in pink plastic (a bath hook for my daughter) only to discover I was unable to back the black ABS out of my MK5 plastruder.  I could extrude, but I just couldn’t back it out with the motor or pull it out after loosening the Delrin plug.

By way of background, and in the interests of experimentation, I had recently tried a few things with my Thing-O-Matic that are kinda contra-indicated by the assembly and usage instructions.  In no particular order, and at different times I had:

• Kept the plastruder warmed up and let it sit for a while
• Let a filament run all the way into the plastruder and shoved another filament in after it

After trying the above and a few different filaments recently, I noticed a  whitish smear along the inside of my plastruder.  The smear was between the toothed pulley and where the filament entered the heater barrel.  I didn’t think anything of it since I had still been able to extrude and print.

Obviously, being unable to remove filament from my plastruder is not really an option.  In order to fix this problem I disassembled my plastruder.  I quickly discovered that the white smear wasn’t just along the path of the filament.  Apparently I had managed to ooze some plastic up out of the heater barrel, around the top of the heater barrel, around the circular hole in the acrylic base to the plastruder, and around the entrance to the heater barrel all along the inside of the plastruder.  This had the effect of “gluing” the acrylic plates of the plastruder together.  Fortunately, there wasn’t a lot of plastic and it came apart rather easily.

The only explanation I have for this is that I must have kept my plastruder hot for too long without running the extruder motor.  This would allow the heat from the extruder to travel up the barrel and essentially liquify the plastic.  Then, once I started up the extruder motor, it must have squished the plastic out of the heater barrel and up into the plastruder.  I also suspect that jamming one filament in after another exacerbated this problem by squishing the filament entering the the barrel with the new filament. ¹

With the plastruder disassembled I found white smear could be scraped off.  It had a gooey residue-like consistency – like old toothpaste.  It was easy enough to scrape it off with a putty knife.  Since I already had the plastruder disassembled, I flossed the extruder toothed pulley.  I also was able to remove the filament with everything apart.  I discovered that the black ABS filament was also covered with the white plastic residue.  The extra width created by the residue on the filament probably contributed to my inability remove the filament in the first place.  I also noticed a few notches ground into the filament from when I was trying to back it out.

Once done, I reassembled the plastruder, reinstalled it, fired up the Thing-O-Matic, heated the plastruder, and did a test extrusion.  All in working order!

1. Perhaps it even squished the first filament up against the sides of the plastruder causing the smear in the first place. [↩]