Heres' a mock up of the strecher/skidlog connection. Tenon OD is 5 inches vert. by 7 inches horiz. and the legs are 3 inches and 2 inches wide. Tenon depth is 3 1/2 inches. I'll do a better job on the real ones.

The 2x6 represents a cross tie log. Tenons 3 inches long by 2 inches thick, on the ends of the cross ties, will fit into a corner mortice in both the strecher and the skid log. I've changed the cross tie location to run diagonaly across the frame instead of perpendicular to the skid logs and strechers. That makes all four corners 4 piece joints.

The strecher logs minium diameter is 9 inches and its max diameter is 11 inches so I'm making all strecher tenons as if all the ends were 9 inches. I'll put the mortices in the skid logs at a height to make the top of the strechers and skid logs come out to some average elevation when the machine is sitting upright. So lowering the mortice hole in the big end of the skid log and raising it on the small end.

SWIdaho

Progress continues. I have one mortice left on a skid log and then I can do a trial fit. The first PIC is two strecher tenons and templates. The bottom leg is wider than the top. The gap is the mortice for the diagonal double cross tree. It also shows one of my very acurate mistakes.
The second PIC is two mortice holes on the skid logs.
The third PIC is the diagonal double cross tree. It's upside down. I'll cut a two inch thick 3 inch deep tenon on each end, on a 45, so it will fit into the corner mortices in the strecher/skid log joint.

Later SWIdaho

pretty cool -- thanks for the update!

Hello Gabel, thanks for looking in. The frame went together with out problems and stayed together when the come-along was released. I have some pictures of the frame, corner detail, and the tension cable/brace pole solution. When I try to preview the post with pictures the preview window says "Frobidden" "you do not have permission to acess this document." Preview without photos and preview works right. The pictures are from the same source as all the rest in this thread.

Later SWIdaho

Done! I still need to buy a hoist cable and hire a crane to set the mast. The base is 16 ft. square, the mast is 22 ft. tall and the boom is 40 ft. long.

http://i188.photobucket.com/albums/z18/cdbower/mastup.jpg

Hello djswan. Awesome idea, a juxtaposition of form and function. Like building a table with hammer and saw and then the hammer becomes a fork and the saw, a plate.

A couple more "off topic" shots. These have little to do with wood joinery but I just didn't think I could make a mortise and tenon joint between mast and brace pole, fit right. The first pic shows the brace to mast connection. That's a two piece clamp with 4 lags into the mast pole. The second pic is brace pole to base connection.

Cool stuff! I really like the star washers formed to the logs. Maybe I missed it earlier but what are you planning to pic with it?
kfhines

Hello kfhines. This machine is mostly for entertainment. I built it because my uncle had one on his ranch and most original machines in this area are in very sad condition. So I guess you could say it is sort of a historical reconstruction. The 4 brace tie downs, (second pic) have washers that have my initials and the year (D B 0 8). All in all it was a fun project. It is overbuilt so the grandkids can swing on it safely. Thanks for looking in. IDA.