Modifications for China CNC 1610

Here are some modifications I did for my 1610 China CNC

The power chain I use is this one (thanks to GeraldO):
https://www.thingiverse.com/thing:119814. I scaled it down to 90%, 75% 75% that the width fits to the aluminum profile (~20 mm). The part with the reduced size is attached as well (chainLink.stl)
The "ends" are modified chain elements:
1) ChainEndFrameSide.stl (use M3, 8mm, T-nut M3 to mount)
2) ChainEndSlider.stl, which requires CNC_EndStopZ_W_PowerChain.stl and 2 counter sunk head screws M3, 16mm and 2 nuts M3

The end-stop holders are completly my design. I use the following switches:
https://www.amazon.de/gp/product/B01LX5I5J2/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1 and screws and nuts M2, 16 mm.
X and Y end-stops can be turned around one of the screws to change the distance a bit.

The Y end-stops are mounted with tin flat head screws 5.5 mm to the top of the aluminum profiles left and right

The X end-stops are mounted using a M5 12 mm screw and