Making a mount/sled/easel out of metal

With the cost of wood being so high I decided to make my easel out of metal from the following directions... Any pointers? 

https://forums.maslowcnc.com/t/unistrut-frame-designs/1267/2?fbclid=IwAR27SWDXIIpdFzx10rLjJlVc79kNrlMo2Gnym8vvs2TtWzGOChPsKew9Xn4