I have a home garage gym that I'm looking to improve on. I'd like to build a pullup rig in my backyard and I plan on using 6x6's to do it. My plan is to have two 6x6x10's and two 6x6x12's. The tens will go on the outside of the rig, and the 12's will be on the inside.
My intent is to have two normal pullup bars on the outside of the rig and then have the inside of the rig tall enough to build both a salmon ladder and hang gymnastics rings on it for muscle ups.
I'd like to sink the posts as shallow as possible (for maximum height) while still ensuring that it's sturdy enough to use, but have no idea how deep this is and I can't find any references that deal with 6x6's.
I expect them to be around 5ft apart from one another in a straight line, not a box.
How deep should I sink the poles and what are the tradeoffs? I definitely plan on cementing them in the ground.