This is a simple spool for bulk cables, wires, thin rope or clothesline. There are two sizes: 20cm (slightly less than 8") wide and 11cm (about 4") diameter. Both are about 5cm (~ 2") wide - 45mm of usable width internally.

The design uses a simple locking mechanism that should be a tight fit on most printers, so usually assembly should be easy and not require any glue. Each spool consists of two identical discs and a central cylinder.

If the locking mechanism is too loose: add a few drops of CA glue (gorilla glue, super glue) into the locking gap of the cylinder, lock the disc and let it dry for a minute.

The round holes for holding the cable in place are 5mm (1/5 inch) wide.

Printing

Any material can be used. If you plan on using the spools in an outside environment (like leaving them in your car in the summer) - use a more heat resistant material (like PETG or PC) and use very light colors.

Print the discs lying on their flat side with the locking mechanism sticking up. Default infill settings will work. No support is needed. You need two identical discs - either the large one or the small one. For the large version you will need a print bed that can accommodate at least 20cm in X- and Y-directions.

Print the hub cylinder standing upright. I tried to minimize overhangs, so normally no support structures will be needed. A brim is recommended to improve stability during the print. I used cubic infill to make a more robust internal 3D structure - rectilinear may produce uneven material distribution - use an infill type that varies its pattern in the Z-direction or use 100% infill.

The provided 3mf files already contain the correct settings for PrusaSlicer - you only need to select your own printer type. If you print the large version: on a Prusa XL or similarly big print bed - add a second instance of the disc. On smaller printers (like MK4S or CoreOne) - print the full project once and then hide the cylinder and print only the disc, so you end up with two discs and one cylinder.

If you use the prepared GCode files: the small version prints in one go, the large version is printed in two parts.

FreeCAD

I included the full FreeCAD project for your reference. There are 3 files: CableSpool.FCStd contains all the designs, the other two are merely assemblies showing how the components fit together.

In the main file features are named as best as possible, so you can find settings if you want to change things.

The cylinder and mini disc reference the big disc for fundamental measurements.