The dark side of new, FAST FDM printers…

My FDM printer experience stretches back to making a Mendel RepRap around 2012. My first semi-serious FDM printer was an Ultimaker 2 - and I used that particular printer for almost a decade.

I bought a QIDI i-fast as an investment to make/prototype engineering-grade parts. The 120mm/s speed felt pretty fast to me, considering my previous experience. The Creality Ender v3 S1 that I got for quick or small parts in PLA wasn’t any faster.

Seeing some of the newer consumer FDM printers in action at Micro Center was a bit of an eye opener. 600mm/s? Sweet lord. Sure, you’re not getting that kind of speed on all layers, with all filaments, or with all quality settings, but the fact that the printers (and extruders) are capable of that at all is astonishing.

I bought a Creality K1C and proceeded to put it through its paces.

Umm….

What I noticed was that the acceleration/deceleration of the print head created forces that overwhelmed the mass of the printer (27 pounds). I could turn down the speeds in the slicer, or in the Creality Cloud interface, but that’s not really a fix, per se. Instead, the printer would really benefit from the i-fast’s extra 50 pounds. Oh well.

Taking the K1C off of the table I had it on, and setting it on the floor, helped somewhat. The proper fix, though, is to affix the printer to something more rigid and massive. After all, the more you can control the transmitted motion of the device, the less force will be transmitted into the print - which becomes a bigger issue the farther the build plate is from the nozzle.

The temporary fix consists of brackets made of 2020 that attach to the top of the table, and hold down the left and right sides of the top of the frame. It’s not perfect, but it does allow for the “top hat” cover to be added or removed without any interference. With both sides tightened down, it applies about 60 pounds of clamping force. That’s enough to quiet the mechanical thrashing, which allows for good print speeds without failed prints or poor print quality. That said, I don’t really print over 250mm/s.

This basic principle applies to any really fast, but relatively light, printer out there. I’ll put together a video or some photos on this.