Here i made a over engineered Spool holder for 1 KG spools.

I made mine from a steelplate 50mm*125mm*5mm and two 20mm square tubes with a length of 100mm and welded on the steelplate. Give it a nice black coating.

With the steelplate and the square tubs there is way more stability.

Finally put everything together and insert the spool.

Max Spool dimensions:

Outer diameter: 205mm

Inner diameter: 50mm

Width: 80mm