This week I’ve brought my “Kevbot” 3D printer back online.  It’s a modified Makerbot Cupcake with a custom z-stage, Acme rods and no end-stops (dangerously:  that’s how I roll!).

I did this:

That’s a test print I did to make linear bearings.  I’m trying to get an idea of how I need to adjust idealized (i.e.: computer model) bearings so that real-world prints create precise-fitting bearings.  Each hole in the test bearing is 0.1 mm in radius larger than the next smaller.  That led me to design and build a real bearing to which I can attach a 3D printer Z-stage.  Here’s the result:

Smooth linear motion.  It’s not perfect, yet, but it’s a few cents worth of plastic versus ten or twelve dollars for a similar commercially-available bearing.  A couple more tweaks and I’ll be on my way!

Also, I dialed in some changes to the temperature of the heated build platform that gives me much more reliable builds, consistent shrinkage, and nice separation from the “raft”.  It’s been a productive week!