Haha, just a bit. I've actually been thinking along the same lines as you though. I can't weld anything to the inside since the endcaps are welded in place, but I'm thinking that welding on some chunks of metal on the outside is worth a shout. Looks aren't important so no worries there

Glad I've got the robots ready quite early this year, leaves plenty of time to faff around with things like this!