X Belt holder self locking

5th April Update: the block was 10 times too big. I scaled it down and uploaded as v3.

After I printed a new X-carriage https://www.thingiverse.com/thing:2469435 for my Anet A8 I realized that the included X-belt holder by itesdahl was to big for my GT2 belt. When tensioning the belt it always slipped a tooth.

I found the X-belt holder from c0ryp1 https://www.thingiverse.com/thing:2795893 but that holder didn't have the right holes for the X-carriage.
I used his locks but designed quickly a new block with the 2 holes having the right size for itesdahls X-carriage. They are 50mm apart and 4mm in diameter.

To fix the holder to the carriage I used M3 screws with washers and nuts.
I didn't use a spring as I think it is not necessary.

Make sure to have a belt tensioner installed before you use this holder!