3D Printing: My Jumpstart

During the Time of the Virus, I decided to jump into 3D printing. I’d been looking at printers for a while, probably since 2018, when I had a colleague who talked about 3D printing the odd part for his cars.

Finally, this March, I pulled the trigger on the Ender 3 Pro, from Amazon. Mostly because it was the only one available in a few days (at that time, I also looked at another one, but it rapidly became unavailable during the supply chain crisis that affected all retailers). However, I did find a lot of supporting good reviews that tipped the scales for me in favour of the Ender. The price was great as well, for around $350 CDN.

The Ender comes mostly disassembled, and part of the fun and learning is actually putting it together. Assembly included plugging in the wiring harnesses into the steppers, putting together the rails and belts for the X-axis. The more delicate pieces such as the base and Y-axis, the electronics are all pre-assembled.

It took about an hour, with some help, to do so, and the instructions are fairly decent, with the fasteners in separate labeled bags. More impressively, it comes with some decent accessories, like a scraper, side cutters, nozzle cleaners, extra extruder nozzles.

At the same time, I’d purchased the aluminum extruder upgrade, which I found to be unnecessary, since the Ender 3 Pro version has the extruder upgrade anyway, but this regular Ender 3 would likely benefit from this.

The first print I tried after assembling the Ender was one of the samples on the included micro SD card using Amazon’s AMZ3D PLA filament, and it came out impressively well. Downloading other samples from Thingiverse also yielded really good results as well.

The Ender 3 Pro comes with a textured flexible magnetic build mat that works well for PLA adhesion, and lets you remove and flex the mat to get the printed pieces off.

Useful Upgrades

I’ve added / changed the following:

  • Printed filament guide
  • Printed wiring clips to guide the ribbon display cable
  • Printed a back cover for the display
  • Silent mainboard upgrade (makes a huge difference in stepper noise)
  • Glass bed for printing ABS

Calibration

The Ender 3 prints really well out of the box, and would work great for creating standalone items (vases, pots, etc.) that don’t need to fit into other existing parts accurately. I went through some extensive calibration steps to try to print parts that require dimensional accuracy like clips and accessories for lights or cameras. I had to do the following:

  • Calibrate X, Y, and Z steps
  • Calibrate extruder feed rate. The stock setting extruded less filament than expected (i.e. when commanded to extrude 10mm, it would extrude 9.5mm), so this was adjusted, resulting in having to dial down Cura flow settings to about 90% to compensate.
  • Find the right retraction settings to reduce stringing
  • Find the ideal setting for line width for Cura to get the right wall width. This is a combination of line width and extruder flow

Dimensional Accuracy: The Challenge

What I’ve struggled with for dimensional accuracy is wall width. When designing parts, the wall width squishes out horizontally during extrusion, causing the dimensions to be affected by twice this squish amount. The key is to accept this amount of squish and have it factored into the slicer calculations. The problems is that some amount of squish seems to help with the wall layers adhering to each other, so getting great dimensional accuracy may come with sacrifices in part strength.

Another factor where wall width comes into play is in the X and Y printer calibration. I had calibrated the printer using a 20mm cube, but hadn’t taken wall width into account. Since wall width is part of the

Another approach is to just accept the printer characteristics and adjust the design’s dimensions (e.g. shrink the measurements to reflect the output). I’d rather not do this, but the reality with dealing with materials may require having to do so, at least to some extent).

So far, I’ve been working with Cura’s line width setting at 0.5mm for a 0.4mm nozzle, which helps to factor in the squish factor (normal guidelines suggest 1.2 to 1.25 x nozzle size, so 0.5mm for 0.4mm nozzle fits nicely).

Given what I’ve learned, my sequence of calibration might go in a different order, namely:

  • Calibrate extruder feed rate
  • Slicer flow rate calibration in conjunction with wall line width calibration
  • X, Y, and Z calibration. Note that Z calibration isn’t affected by wall line width, so it could be done almost any time.

Printer Pros

Good price and lots of support on websites. Just being able to read and absorb articles that are Ender 3 specific is a fantastic learning experience, so in that regard it has been a really good starter 3D printer for me. Having to put it together helped in my understanding and comfort in swapping out parts, and just overall how the printer works.

Prints well right off the bat with PLA, easy parts removal (with Pro version magnetic bed).

Printer Cons

Somewhat noisy – this can be remedied through the silent mainboard upgrade and the fans can be changed out, but it would have been nice to have the silent mainboard as part of it.

Need to add more bits to it. It might have been good to have more of the upgrades as part of the package, but on the other hand, it would have increased the price, and wouldn’t have been as much of a learning experience for me.

Verdict: Excellent printer for the price. Really good starter 3D printer