Summary

First thing printed !! The wingnuts to adjust the hotbed are not very confortable to turn, it is a two hands job, so the first thing I printed are these knobs. As I had only some nylon to print with, I added a .5mm skirt to make the piece stick better to the bed as in the first try it got loose and went moving around. I printed without supports, and when the print was high enough, I paused and drop the M3 nuts in, so the top side would have something to lay on. Don't put the nuts too soon or the extruder will catch on them.

You can make this in different sizes with this customizable heatbed knob customizer...
https://www.thingiverse.com/thing:2977755

I created these links where you can find all common filaments and spare parts at the best prices. These are just links to selected eBay and Aliexpress items, where I normally buy spare parts and materials for my printer, prices are excellent and products are good. If you buy something from here you will support me a little bit to make these projects.

1Kg PLA Filament - eBay
1Kg ABS Filament - eBay
1Kg TPU Filament - eBay
1Kg PET Filament - eBay

Complete extruders - eBay

Heat blocks and heaters - Aliexpress

Standard nozzles - eBay - Standard nozzles Aliexpress

Volcano nozzles - eBay - Volcano nozzles - Aliexpress

GT2 pulleys - eBay - GT2 pulleys - Aliexpress

GT2 belts - eBay - GT2 belts - Aliexpress

Linear bearings LM series - eBay - Linear bearings LM series - Aliexpress

NEMA 17 step motors - eBay - NEMA 17 step motors - Aliexpress

3d pen - eBay

100$-200$ 3D printers - eBay - 100$-200$ 3D printers - Aliexpress

200$-300$ 3D printers - eBay - 200$-300$ 3D printers - Aliexpress