This is a printable tripod leveler, with space for a bubble spirit level. You install the tripod leveler between the tripod and the head. It let's you get the head completely level for better panning performance. It is also great for setting a level base for panning time lapses with any of the great panning mechanisms available on Thingiverse.

The leveler itself has 6 M3 holes top and bottom, (siting on a circle of diameter 26.7mm), and I've made top and bottom adapter plates which take a 3/8" 20 bolt and nut respectively. I designed with McMaster Carr parts and tested it with parts from the open bins in Home Depot. (I have printable 3/8 to 1/4 inch adapters in my things.) There are 2 top pieces, one which will work with a 1 inch bolt, and a lower profile one which may need a shorter bolt, depending on the tripod head you are using.

This will take a lot of weight if it is centered, because the weight is carried by the pillar at the center of the joint. If the weight is not centered, you may be limited to small DSLR's as the largest cameras. You lock it by turning the top ring clockwise, it will sometimes take a bit of force to release it.

All parts print without support, I suggest lightly sanding the surface of the cap after printing.

You need 6 to 12 M3-10mm screws for the top and bottom. You can just use three on each end unless you are supporting something heavy.

The top adapter will press-fit a 10mm circular spirit level, these cost less than a dollar each (in packs of 10) on Amazon (http://a.co/d/1r32IT1). Depending on how well dialed in your first layer is, you may need to deburr the hole before you can push the level in.

I suggest printing with at least 3 perimeters, to ensure strength in the gripping arms, and a fine layer height to ensure smooth action. (as an option: if you print the cap in wood filled PLA, it will polish to a nice smooth surface, with good frictional priorities.)

To assemble, screw the top and bottom plates on, place the cap on the base, and slide the cam over the top. Align the tabs on the cam with the gripping arms to slide it down into place, then twist to lock.