Sanding block

Hello, i've read and printed a lot of things from thingiverse an this is my first topic. You can use solid sandingpaper 75 x 533 mm here: https://www.amazon.de/gp/product/B01N74SP7O?pf_rd_r=3H1P628X7R277Z257W39&pf_rd_p=4ba7735c-ede3-4212-a657-844b25584948&pd_rd_r=9d191dfd-7480-4265-8e1c-89752a5b9acb&pd_rd_w=c6dKZ&pd_rd_wg=8spas&ref_=pd_gw_unk .
The advantage ist, that you can use more solid sandingpaper with a fiber ribbon a the back of the sandingpaper. The resukt is that the sanding paper will last longer than the normal ones.
I've printed all parts without draft or support with 25 % infill. Expected the "Bolzen". This part needs a raft and an infill of 100%. In an imgage you can see in wich direction i've printed the parts. You nedd no additional parts likes screws to mount the parts together. A vise would be an advantage, because the "Bolzen" need a little bit of force to press ist in. Pay attention to the chamfer on the parts to press the parts togehter and don't forget to put