3D Printing

Continuing on the “my apartment is small and making things is hard” theme, I have a 3D printer! It’s one of the few tools/machines that can practically be used in an apartment - it doesn’t generate sawdust or chips or dangerous fumes, as opposed to woodworking, metalworking, or laser cutting (all things I’d love to be able to do in a garage/workshop space eventually). I bought the Ender 5, since reports indicated the Ender 3 was excellent (for the price), and the Ender 5’s design allowed it to have an even smaller footprint (it has a gantry, as opposed to the Ender 3’s moving build platform).

The printer was exceptionally easy to assemble and get running out of the box, though my very first print was a failure, due to the only power outage I’ve ever experienced in NYC. I’ve had a few issues with the printer since setting it up, which I’ll go through one-by-one here, and then go through a selection of the things I’ve printed over the ~year since I’ve had the printer.

Issues

Issue #1: Bed Adhesion

The Ender 5 comes with a heated bed and a magnetic flexible build surface with a softly-textured plastic top. Prints stuck fairly well for about the first 6 months (call that 20-25 prints), and then I couldn’t get anything to stick whatsoever. I tried different temperatures, speeds, extrusion multipliers, raft, brim, etc, but couldn’t get anything to stick reliably. I releveled the bed at least 10 times, all over the span of about 5 months. I would get the energy to go wrestle with the printer for a whole weekend about once a month, never to any avail. Finally, I decided to buy a dial test indicator, because it looked to me like the extrusion distance was inconsistent. Lo and behold, the bed surface wasn’t even remotely flat - it was out by about +/- 0.1mm, which is enormous compared to the 0.2mm layer height. I bought a glass bed so that I’d have a flat surface, and replaced the included build surface with glass. Since then I’ve had almost no issues with bed adhesion, and the first layers have looked amazing.

Issue #2: Slicer Settings

Tiny extrusions

When printing gears (16DP), the default Cura settings tried to insert a tiny top/bottom layer into the tip of each tooth. This would have resulted in extreme amounts of retraction and severely slowed the print. I tried slicing in Slic3r as well, and got the same result. I eventually resolved this by setting it to a single wall, but with a wall on the infill. I’m not sure why that made a difference, but that seemed to fix the issue.

Bad infill

The default Cura infill pattern is Cubic, which involves infill lines crossing each other - this is done without a retraction, so the extruder plows through the infill. Normally this isn’t much of an issue, but it does produce larger-than-normal lateral loads on the print, which can break it free if the bed adhesion isn’t that good, or if the contact area is relatively low. I like Zig-Zag as an alternative, which produces a very similar pattern to Grid, but alternates which direction the infill goes on each successive layer.

Issue #3: Warping

This is a new one for me - I recently finished a roll of CC3D Silk Blue PLA, and am now using a roll of Hatchbox White PLA. This roll hasn’t treated me very well so far, resulting in significant warping, to the point where multiple prints (4 out of the last 7) have come unstuck from the build platform. I’m not quite sure why, and definitely don’t have this printing as reliably yet. For now I’ve cleaned off the glass bed and draped a blanket around the printer to make a poor man’s heated build chamber (mostly to block drafts from the AC), and things seem to be working quite a bit better. I suspect that the +/- 0.03mm spec on the Hatchbox filament (vs +/- 0.02mm on the CC3D filament) might also be a contributor to the issues here.

Prints

Finally, a collection of some of the things I’ve designed and printed, almost all on this printer within the past year or so. I went ahead and uploaded many of them to Thingiverse.

Thanks for reading!

Tags: #engineering