Hi

I am very tired of trying! I liked to build a simple hollow cube with snap hook fastening. I did it in this way:

1- drawing a rectangle sketch

2- extruded boss/base it

3- using shell command

4-mirror it by a reference plane

5- try to add snap hook and snap hook groove, but I can't add snap hook groove!

It gives me an error ... How should I build a hollow cube with snap hook fastening step by step?