I daren't leave a piece of box without an end cap welded on. Mind you, everything is made from 40mm box.
As long as it is made from strong enough steel you won't have any problems. Perhaps make it so that every other vertical bar is removable. An the horizontal bar is easily adjusted.
Here are a few pictures of one i made a while ago,Roller on one side with r clip so can be removed easy, the creep opening adjusts by it sliding inside the open ends of the frame,it has a spring bolt to set the width so can be opened if one gets stuck, the bottom rail is 15" of the floor and has not been a problem (spring bolt and clip not yet fitted in pictures) i just set it to a closed gap and use as a gate when not needed as a creep,certainly helps at weaning time
Very smart @Forever Fendt will put a photo of mine up tomorrow, billy band, exhaust clips and paint v r clips, hinges and galvo
Here goes ours. Calves aren't big obviously. Back end calves, will be in here till April. Fine and simple though.
Been making a couple of new ones for in the slats. Creep is at hinge end ie. furthest from feed fence - couple of brackets to drop a pin in if it needs to be closed