Let me start from answering probably the biggest question - WHY ?

Answer: Why not ?! - for fun only.

K2 Plus has a great app and printer screen where you can actually do everything you need. KNOMI(2) or any other screen has no real usage to be honest and is only a gadget.

=> It lets you relax while watching your printer in action. ;)

Since both KNOMI and Waveshare screens are fully programmable, you can display anything you want on them—enhancing the experience with data and status updates from the printer.

This project is more about where to get the power from K2 to run such screens rather than the cover itself. You can model your own cover based on following key dimensions:

Project Stages:

WARNING: DO NOT PROCEED IF YOU DON'T KNOW HOW OR DON'T FEEL YOU CAN DO IT. Following steps risk damaging your printer. Caution advised.

1. Printing the cover:

The current version of the case is designed to fit perfectly with the notch on the screen so that, once inserted, the LCD panel sits flush with the enclosure. The notch depth is 0.50mm, which can be a challenge for FDM printing. You’ll definitely need a well-calibrated printer and filament. If you have a resin printer, this should be much easier to print—just make sure to use a resin that’s resistant to higher temperatures.

The case requires 2 neodymium magnets, size 5x3 mm.

2. Power - wiring:

One of the biggest challenges was figuring out where to “steal” power for the screen from the K2 hotend. Of course, you can always use an extra USB or 2-wire cable and run it to another power source. However, my priority here was simplicity and a clean solution.

There are 3 ways to power the screen:

a) External source (easiest way) – Route a longer cable alongside the other wires coming from the hotend. Lead it outside and connect it to a USB port (or another +5V source).

b) Invasive method (NOT recommended) – Cut the power cable for the filament sensor in the hotend and split it to power the screen as well. I didn't want to damage or change my printer in any way that is why I do not recommend this option. It is easier but you are cutting an original K2 cable - not sure if there are replacements.

Below you will find description of the wiring.

c) (RECOMMENDED) Prepare a new connector splice - screenshots.

Description of recommended solution (c):

To do that we will need a connector and a plug. We will connect our splice to the hotted and K2's plug to our splice's connector.

K2's filament sensor wiring:

Looking at a K2's hotted filament sensor (located at the top, behind Bowden tube) FROM THE LEFT (I colored mine):

1) signal

2) GND

3) +5V

I would recommend double-checking this on your K2 in case Creality did different wirings during production. I only have one K2 to test...

The idea of a splice is to unplug the K2's filament sensor plug. Connect our splice plug (GHR-03V-S0 that will offer a new connector (BM03B-GHS-TBT) for K2's plug and a wire for the screen ended with 2 PIN plug (GH1.25 2P).

I've made my very compact but this is not necessary. In fact it will be easier for you to do it all on longer wires. Here's mine:

Parts list:

- (required) 2 pieces of Neodymium magnets. Size 5x3

- (required) Waveshare LCD screen (1.28inch) OR KNOMI1 / KNOMI2

- (wiring) 1x male connector: BM03B-GHS-TBT

- (wiring) 1x female connector: GHR-03V-S. Optionally same plug but with wiring installed.

- (wiring) 2x pins for female connector (if you use not wired one): SSHL-002T-P0.2

- (wiring) a 2 PIN battery connector for the screen: GH1.25 2P (we only need + and -)

All parts are available on Amazon or Aliexpress or producer's websites.

What's next?

A) I am working on a new version of a printable cover inspired by "Kenny mod for KNOMI" where you have a latch to attach the screen and close it. It will be much easier to print and to install.

https://www.printables.com/model/496608-kenny-mod-2-for-the-btt-knomi-display

B) Print in place splice adapter (to hold connector and plugs in a small cover)

C) +5V / GND splice connected to K2's hotted top bolts. The cover will have wiring to its top sockets and the connection will be made when cover is installed on the hotted. There will be no wiring connections so you will be able to easily take off/on the cover from the hotted!

Catch me here or on Facebook if you have any questions or need help.

Special thanks to Kevin from Creality for being a proxy with dev team and helping with the wiring options!

The EYE Project: KNOMI / Waveshare Screens K2 Hotend Cover

FDM print placement for best results

Placement tests: 0.08mm layer, 2 walls, 15% infill