…code, cg, electronics, 3d printing…

Based on my previous post, I wanted to get better results from my sand-cast.  Things I learned from last time:

• Even though I had a split mold, the vertical edges caused the mold to tear-out during removal.  I have a feeling this is due to the ‘ridged’ sides the 3d-printing causes, making the walls ‘grip’ more.  Because of this, I adjusted my 3d model to have slightly tapered sides.
• The extruded text on my first model suffered the same problem as the above issue.  To resolve, I simply made the text extruded much less.
• The previous split mold only had one anchor point, in the middle, to join the two sides:  When connected it gave more yaw-play than I wanted.  The new version has two anchor points on either side.
• I watched a bunch of sand casting videos and read over multiple sites to make sure I got the sand cast itself created properly.

Based on all that, the end result turned out really nice:  Sprue cut off with saws-all, imperfections ground off with an angle-grinder, and polished with a Dremel:

Here’s a shot of it freshly pulled from the cast with the sprue still connected:

And here’s a shot of the 3d-printed two-part mold.  It took just under 4 hours to print on my Makerbot Replicator.  200 micron layer resolutoin, gray PLA, 220 deg C on a glass build plate covered in blue painters tape:

And finally, here’s a movie of the furnace just before it was time to pour:

I shot it with bare hands:  I got really hot, really fast 😉

I’ve been experimenting with some backyard sand casting, and have had the desire to try and cast a 3d-printed object. I’d heard you can do a “lost PLA” cast, where the molten aluminum vaporizes the printed item, so I thought I’d give it a shot.  Long story short:  Works… sort of.  This is my first try, so I didn’t really know what to expect, but the results were far less than I wanted:  No detail in the object, and not all the PLA totally melted: I printed the object with only 5% infill and 1 shell (to generate as little material as possible).  Regardless, it does make a good conversation piece 😉  In the future I’m going to get better sand (finer grain, better clay binder) to help preserve the detail, and probably try for a real lost-wax solution (3d print a mold for the wax), or a true sand-cast where I remove the item to be printed and simply fill the void with metal.

The end result is (an attempt at) the logo for the company I work for, Sledgehammer Games  (a sledgehammer head seemed something worth forging):

A dime is next to it for scale

You can see on the left and right sides where I had to grind off the sprues.

Here’s a shot of my “flowerpot furnace” in action melting the aluminum for the project:

And one with the top removed, showing the red-hot crucible:

Today I printed a mini-“Sledgehammer Games” logo (the company I work for).  I thought it would be an interesting practical experiment using a custom-modeled .obj file, tweaking it to print well on the platform.  I think it turned out pretty well.  Next up will be a life-size version 😉