Wireless ZX Spectrum Keyboard - TeckNet X 315 Mod

ZX Spectrum inspired key caps for the cheap TeckNet X 315 ultra slim wireless Mini keyboard.

The project uses manual multi-colored print, so you can print it on a standard Prusa without an MMU3 unit.

It requires:

• TeckNet X 315 ultra slim wireless Mini keyboard (available from Amazon)
• 0.25mm nozzle

Filaments

• PLA Grey (eSUN ePLA Matte)
• PLA Black (eSUN ePLA Matte)
• PLA White
• PLA Red
• PLA Light green
• PLA Navy blue
• PLA Sky blue
• PLA Purple/Magenta
• PLA Yellow

Fonts (see Fonts folder)

• Helvetica Light font
• Franklin Gothic Demi Condensed
• Cadra Light
• Cascadia Code

For getting accurate colors, you can use the Filament Printing Technique, where you print a spiral of a filament combining two or three layers of different colors. I'll make a tutorial, but you can find some already available.

Printing

Test Print

Start with a test print of a single key, like Tecknet-ZXKeyboard-Num-3.3mf. Adjust parameters if required (like Z-correction, extrusion etc).

I recommend using slight under-extrusion (97% flow) for all the filaments except for the black and the grey.

A) Manual Filament Changing

Use 3MF project files from the Manual MM folder.

1. For each project, using print sliders see which filament is the starting one (usually white).
2. Load the first filament
3. Slice the gcode and send it to printer
4. On the printer press “OK” when it warns you about a possibly wrong filament (don't worry - it just warns you to check whether the currently loaded filament matches the first one in the print)
5. The printer starts printing.
6. When the printer pauses, click on the “Resume” button on the printer, and carefully wait for it to display a message like “Next filament is RED" (or whatever color comes next), as it will be displayed only for 4 seconds.
7. Wait for a few seconds for the printer to unload the current filament, and load the new one as instructed in the previous step.
8. When it asks is the color OK, click OK (it will wipe the head on a wipe tower, so the “Purge more” is not mandatory).
9. Just hook the extracted “poop” of filament with an Allen key and wait for the head to move away.

B) Using MMU

Change the printer profile in the PrusaSlicer to MMU3, assign the proper colors, and go!

Cleaning the Printed Keys

There are no supports nor brim required, but you will need to clear the stringing from the tiny hooks on the bottom of the keys, if there are some. Using a quality, dry filament will reduce stringing, but there should be absolutely none. Carefully remove any stringing using a thin exacto-knife or a razor blade.

About The Keyboard

Overview

TeckNet X 315 Ultra Slim Wireless Mini is a cheap but surprisingly good wireless keyboard, that uses a proprietary wireless USB dongle. 

It is supported by Retro The Spectrum computer, with some exceptions:

• There are no Power nor Option button equivalents on the keyboard, so for those two you will need to use the keys on the computer.
• For the Symbol Shift Some emulators use Right Shift, and some (like The Spectrum) use the Control key.

Removing the Regular Keycaps

Carefully remove the following key caps: 

• Numeric row 1 - 0
• Q - P
• A - L
• Z - M

1. All the keys have a plastic bracket that needs to be carefully removed. You will need a tiny (watch) flat screw-driver.
   
   
    
2. Gently pry open lower side of the keycap (the one facing you) and push the right lower bracket pin exactly as shown:
   
   
   
   Now the lower part of the bracket should be free:
   
   
    
3. Now you can access the bottom side of the keycap to release the bracket from the right hinge as shown here. Use the screwdriver to push it out.
   
   
    
4. Now release the left side:
   
   
   
   The bracket should now be free.
   
   
    
5. Return the lower part of the bracket back into the hinge:
   
   
   
   
   
   
    
6. Now you can mount the new keycaps by first slipping the upper part of the key into the upper hinges, and pressing the bottom part to click it in place.
    

Removing the Shift Keycaps

The Left and the Right Shift keys are somewhat different, as they have a metal wire that hook the key to the frame.

1. Carefully pry the Shift key from the upper side to release the metal hook from its hinge, by pulling it to the side using the screwdriver:
   
   
    
2. Now release the hinges from the bottom of the keycap by inserting the screwdriver
   
   
    
3. Now return the metal wire back into the hinges and ensure that the bracket is properly seated.
   
   
    
4. Mount the new Shift keys the same way as the regular ones: first slip the upper part into the hinges and then press the lower part of the key to click it in place. Ensure that the metal wire clicked into the keycap as well.