As my main 3D printer was basically a project in it’s own right, I decided I wanted a cheap, simple printer that just worked. I wasn’t going to mess with it trying to squeeze out as much speed as possible, it just had to reliably produce accurate parts.
Klipper on a budget
I opted for the Kingroon KP3S Pro V2 as it was a very cheap bedslinger printer using linear rails on all axes, theoretically guaranteeing good rigidity. Additionally, it ran the open source Klipper firmware and came with an accelerometer for input shaping. Nowadays these are all standard features in most printers, but at the time these were major selling points.
Cheap for a reason
I found the frame of the printer to be very poorly constructed, and the bed mesh would change due to the Z axis constantly going out of tram. To remedy this, I printed some reinforcement brackets that would bolt the Z axis in at an additional 2 points. This didn’t fully remedy the phenomenon, but with input shaping I’m able to still produce good enough parts for prototyping.
Disaster strikes
The printer ran great for about a month, after which I decided to update the firmware. This was a big mistake however, as running
sudo apt update
sudo apt upgrade -y
resulted in the motherboard being bricked.
I couldn’t get any video output, it wouldn’t get an ip address and the built-in display would just display some gibberish. It was completely dead.
Long live Chinese support
After a bunch of emails back and forth with Kingoon customer support, they decided to send me a new motherboard. The motherboard they sent me was a different revision however, and I never got it to work. At this point Kingroon support decided they had done their part, and I was just left to figure it out for myself.
So here I was, left with a paperweight that was supposed to be my “reliable” machine.
Taking matters into my own hands
Now I was at the point where my workhorse machine was broken and my Anet A8 project was operational, albeit very buggy. I had a Raspberry Pi Zero laying around as well as a spare motherboard from the Anet project, so I decided to use my Anet to print some mounts for the pi and motherboard in place of the original Kingroon board.
I got the printer up and running with my own Klipper install, but in the midst of my conversion there was a short circuit in the toolhead board. This meant I no longer had access to the extruder stepper and nozzle heater. To remedy this, I proceeded to build custom mounts for a Bigtreetech EBB42 Toolhead board .
While I was working on the toolhead anyway, I redesigned the part cooling fan shroud to reduce weight, and the stock fan duct was replaced with a more efficient one.
Current state of the project
After many revisions, configuration changes, frame reinforcements, etc. this printer is finally at the point where I can just send a job to it and be confident it will finish without issues. In order to get it to this state, most Kingroon parts were removed and replaced. Safe to say, I won’t be buying more Kingroon machines any time soon.
While this isn’t the first printer I’m going to fire up whenever I have a new project, it is perfectly adequate for when I’m working on multiple projects or need multiple prints done at once.