Timber frame monkey bars

[dan888]

For a long time I've been wanting to cut my first timber frame and today my son presented me with the perfect opportunity. He requested a set of monkey bars for his birthday in a couple of weeks. So I'm thinking, challenge accepted. He doesn't know it yet but his gift is going to come early in the form of a trip to the lumber yard to pick out some cedar posts for the frame that we'll cut together.

Here's my rough plan. I'd appreciate any comments or suggestions:

Foundation - I'd like to be able to reposition the monkey bars at some point so instead of using concrete piers my plan is to have a short sill beam at either end that is in contact with the ground. I'll drill a couple of holes in each sill and drive some rebar into the earth for stability.

Lumber - My first instinct is to use 6x6 cedar for the frame and would like to avoid treated lumber with the possible exception of the pieces that are in contact with the ground. Cedar is proving difficult to source where I am (just west of Boston). Any recommendations?

Rungs - These are likely going to be galvanized steel pipes connected to the frame with flanges

Design - I'll try to post a sketch later once I figure out how to illustrate the joinery. But you can generally imagine the structure as an elevated ladder supported by two rectangular frames ("bents") at either end with bracing for support.

Thanks in advance for any input.

[rusticretreater]

My wife once took our kids to the local park where they had this big timber playset for the kids.  You know, bridges, turrants, railings, etc.  The kids ended up getting a bunch of splinters.  Just something to be aware of.  Things might be smooth and sanded in the beginning, but time, warpage, kids with pocket knives, etc. and it could be much different.

[Big_eddy]

Cedar is soft enough it will rarely splinter. PT not so much.

I would just drill 2"-3" deep holes in the rails for the rungs, instead of using flanges. A spade bit would make short work of the job.

[doc henderson]

sounds like a great project.  might add a fort at one end, maybe a slide on the other...  how old is your son?  Other uses like a swing, if you think he will get tired of the monkey bars. I like the idea of changing height if he gets bigger (and he will assuming he is 5 and not 28).    I used PT back in the day.  you can put a bigger radius on the edges and less splinters.  Of course, some feel that splinters build character.