Z carriage tightening

I have experienced a couple of issues with my z carriage breaking. The bolts and nuts were put in and fit well but after a while, the router became loose and started to turn. When I tightened the bolts further it snapped on the side with that tightens:
https://servimg.com/view/20338324/2

I then reprinted both the top and bottom of the carrier and it broke again. It looks like the bolt towards the middle of the carrier is too far inward and should be further out. Or maybe I am tightening it too much. Any ideas?

For slipping due to machining forces and vibrations, the standard recommendation on the trim-router spindle (with X-carve's and Shapeoko's and similar machines) is to apply one or two layers of masking tape to the polished metal surface of the router. Tends to stick well and then produces more friction preventing slip.

Fitting the original GG2 dimensions required some impractical and not super effective design choices on the swappable spindle/carriage system. The original carriage being mostly metal enabled them a lot more structure and rigidity in the given space, and our trying to reproduce it in plastic - and then add on the swapping feature - has produced a lot of issues for users.
We have a series of single-piece spindle mounts in testing for the 2.2 releases; I'll shoot you the mesh for one of them if you want to give it a try instead? Uses a couple of slightly longer 5mm or 3/16 fasteners to achieve the same clamping operation but has a lot more structure to it.

EEM-LLC wrote:

For slipping due to machining forces and vibrations, the standard recommendation on the trim-router spindle (with X-carve's and Shapeoko's and similar machines) is to apply one or two layers of masking tape to the polished metal surface of the router. Tends to stick well and then produces more friction preventing slip.

Fitting the original GG2 dimensions required some impractical and not super effective design choices on the swappable spindle/carriage system. The original carriage being mostly metal enabled them a lot more structure and rigidity in the given space, and our trying to reproduce it in plastic - and then add on the swapping feature - has produced a lot of issues for users.
We have a series of single-piece spindle mounts in testing for the 2.2 releases; I'll shoot you the mesh for one of them if you want to give it a try instead? Uses a couple of slightly longer 5mm or 3/16 fasteners to achieve the same clamping operation but has a lot more structure to it.

Sure, ill give it a try. I was thinking about trying to re-design the carrier but I'm not sure it work, so if you have one that might ill print it.