Sanding block for belt sander belts

Sanding belts are of much better quality than the usual sanding papers. That's why I have build sanding blocks from wood and purchased a commercial model. Now I wanted more of them to have a block for all grits I usually use. However, I didn't want to spend another 20+€ for a commercial one from Milescraft nor spend the time to build one from plywood again.

The design was straight forward as I had the required dimensions from the previous designs and it took less than 45mins. However, print time is around 20h but with the very good but cheap PLA I use they only cost me around 3.60€ per piece.

The STL files contain designs for 75x533mm and 75x457mm belts but I only build and tested the ones for 75x533mm as these are the only ones I use and have.

Print orientation is as they are shown in the STL-files. Support: rear from bed only, front everywhere and eccenter none. Infill: 10% cubic with double line except for eccenter where I used 40% cubic with double line.
The design is for a pretty tight fit. Any residue from the supports has to be scraped/filed off!

Yes, the first part turned out pretty colorful as I ran out of filament. As I want two blocks anyhow I will just print the second one in the correct colors and fit them together so they turn out in uniform color.......

A slightly more detailed project report in German language can be found here: https://www.die-heimwerker.net/t70f18-Bandschleifkloetze.html#msg19821

2022-04-04: Someone printed the 457mm Version and confirmed that I got the dimensions right.