A big and overbuilt spool holder for spools up to ⌀38x16cm (~⌀15x6"), printable on Mk4! 

I've had the misfortune of waking up to a spool lying on my printer's bed because my wooden spool holder broke and the spool fell sideways. :(
I decided to make a spool holder that would withstand any spool that I have and never fail!

There are 2 arms - left and right, 2 screws (optional), and 5 different rollers with length chosen so as not to have to move arms if you wish to use a different diameter roller. 

The rollers are 60, 50, 40, 30, and 20 mm in diameter, all equipped with an inner M10x1,5 thread 50mm deep. 

The screws have a layer height modifier starting with thread, which changes layer height to 0,07mm and provides trouble-free use. I would still advise using some sort of lubricant, as plastic on plastic tends to squeak.
You can also use a normal steel M10 bolt, although the screws and handles are more comfortable to use (and match color!).


How to use:
1. Move arms roughly 16cm apart trying to keep it centered, you can use any of the rollers placed into its respective slot as a spacer.
2. Gently pop them into place with slots facing each other.
3. Place the spool on the roller.
4. Insert roller.
5. (optional) Screw with 2 screws from the outside to provide horizontal support.

I hope this spool holder helps someone in need, I can now print with my 2,5kg spools without fear of spool-holder-induced failure!