I'm starting with just the tutorial for the pipe frame for the digging treadmill! I have all the parts for that at least. I'm building this out of 1" pipe so all instances where pipe or pipe fittings are mentioned are designed for 1" pipe.
If you are making a different size, I suggest measuring how long your dog is when lying down, from their front nails all the way to the base of their tail and using that as the length of the digging deck. Then measure the width of your dog from shoulder to shoulder and doubling it for the width of the deck, plus or minus a couple inches. Then to find the dimensions for the height and length you can punch the length of the running deck in a trigonometry calculator like this one.
I chose to make mine extra large so I can still use it as a teeter base.
Step one: gather all your materials.
•Six (6) three-opening pipe fittings. These are a speciality pipe fitting which I was only able to find at Formufit.
•Four (4) 45° angle pipe fittings. These can be found at any hardware store.
•Four (4) 2" lengths of pipe.
•Three (3) 14" lengths of pipe. These will be the width of the mill.
• Four (4) 28" lengths of pipe. These form the height and length.
•Two (2) 40" lengths of pipe. This gives the length of the digging surface.
Step two: put two (2) of the 28" pipe into two (2) of the openings of the corner pipe fittings. Do this twice. Ensure you have an opening facing up.
Step Three: Put a 45° angle pipe fitting on each open end.
Step Four: Put a 2" pipe in each open 45° angle pipe fitting.
Step Five: Attach a corner pipe fitting to each end, oriented with an opening towards the middle of the structure and one opening up.
Step Six: Attach a 40" piece in between the openings on each piece. You should now have two (2) triangular pieces. It may require some manipulation to fit.
Step Seven: On one side, put a 14" piece in each of the remaining opening of one side.
Step Eight: Put the other side on top, openings facing down so it becomes a closed structure.
Congratulations! You just finished making the base of the treadmill!
Do not glue or screw together this frame yet! You should only dry fit it so it is possible to put the plywood support deck in. After that, you can put a screw into each connect to hold it securely during operation. I'll explain how to do that in a reblog of this post once I have the wood. I plan to cut a slot in each of the four (4) pipes that make up the deck and cut a one inch (1") square piece from each corner of the plywood, then fit the pipe around it. But in any event, that's it!