My Quest for the Perfect Ender 3

I've been printing lots of new designs on my Ender 3 for about 6 weeks now (as of the time of this note, and only with PLA). I've found the Ender 3 to be a pretty solid machine that easily tracks with its reputation. Thus far, the performance of the stock extruder has been very acceptable. I've experienced only a single nozzle clog in scores of prints produced thus far. (And, no the Benchy is not among them and never will be.)

IMO, I've found the Ender 3 to be very easy to maintain and acceptably quiet. While it prints only a few feet from my laptop workstation, I can continue my engineering work without distraction. Overall, I have lots of good things to say about it and essentially no complaints.

There are two design elements that I do find problematic, but these are not just for the Ender 3 but for any 3D printer of similar design:

  • suspension of the bed on for screws with springs, and
  • mounting the bed on axially loaded rollers instead of radially.

1. This very common bed leveling design places a mass (the bed and whatever is being printed) on the ends of four narrow, long cantilevers with essentially nothing to resist lateral motion—other than the hole clearance between the fastener and the bed and plate holding the bed. This design virtually encourages resonances.

2. Typically, the Delrin rollers in a linear rail design are loaded radially to ensure that both the chamfered edges are used for the load. (That is, they are mounted and used like the wheels on a car.) For the Y motion on the Ender 3, they are loaded at right angles—an axial load. Now, to be sure the loads are small, but are nonetheless carried on only one chamfered edge (the lower one) of the rollers instead of both edges (as in a radial load design). Moreover, the ball bearings are better suited for radial loads in contrast to axial loads. Thrust (axial) loads are best handled by roller bearings (such are taper roller bearings).

If I designed a printer from scratch, these weaknesses are something I'd seek to avoid if maximal rigidity was the goal.

My typical workflow begins with Fusion 360 to capture the design, export to Cura, then load and print the model using Pronterface attached to the printer with a USB cable.

Which brings up another important point: Tim Hoogland and the TH3D Unified Firmware Package.

I can't say enough good things about what Tim produced; it is a great example of the advantages of an Open Source application and how it can be improved by developers around the globe. If you haven't installed it, I recommend highly that you do; it works beautifully on the Ender 3.

The only change I had to make was to lower the USB/serial baud rate from 115200 to 57600 after I encountered a design which layer-slipped during printing from the USB but which printed perfectly from the SDRAM. Since that change, printing has been without that issue.

This site is dedicated publishing the mods I've made to my Ender 3. My hope is that you'll find them useful as well.

At this point in time, my mods can be catergorized in these groups:

  • Improving filament flow. [Filament Spool Holder; Filament Guide; Extruder Guide Base Plate]
  • Improving cable bundles strain relief. [Extruder Bundle Strain Relief, Z Bundle Strain Relief; Y Bundle Cable Chain]
  • Improving hotend cooling. [Extruder Cooling Fans]
  • Improving "clumsy" or "missing" issues. [Y End Stop; Adjustable Z End Stop; Controller Fan Cover]