motor case engraving

What other ways can I attach an aluminum motor case to the body tube? Is it through engine retainers along with bulkheads? or just use shear pins?

I wish I had Dr Evil's finger quotes, but oh well... So when your coworker has a 80 Watt laser and is looking for ways to have it earn it's keep, you offer suggestions... I trashed my beloved 54/2560 case that was etched by Dr Rocket himself. So in order to maybe help other people out, I gave my...