Today I have a couple pics of some anchors I made at home. I was able to procure some 6″x6″x0.25″ plates of 6061-T651 aluminum. I cut these down into 2″ strips, laid out some hole patterns, and drilled/milled the stuff until I was left with two pieces for each anchor.
A trip to the hardware store, and I put these together using shoulder bolts, spacers, and nuts. I still need to add some sort of strap to them for connection to the tree, my plan is to sew some dog-bone style straps to one end of the anchor.
Each anchor replaces a rap ring and a carabiner, and the eventual goal is to use this type of anchor on a longer line (> 100′).
So far, I’ve made three of these, and they work great for the 50′ lines I usually set up. I don’t have a method for testing their break-strength, but calculations show they are fairly heavy duty. Here are a couple photos: