I'm using HomeRacker to build my new rack.

But if assemble it wrong, it's too tight to remove the pins.

I think the design without tolerance is necessary, so I don't want to change the original size.

I drew a removal kit to remove the pins.
 

It's easy to use, just insert the remover at the other end.
Careful, the Z-axis is very slim, try to print some backup copy. 

 

Design, if you want to know the size.

V2 Update

The top was modified to better hold the top surface in place, and the placement orientation was also changed.