This is a basic height-adjustable shooting rest using a screw-and-locknut adjustment.

It is designed such that no brims, supports, or rafts are needed to print. 

There are four components, but you will print a total of five parts.

The "base" (tripod) which is printed upside-down with the legs facing up.

The “top” which is printed with the threaded shaft facing up.

The “lock" which is printed flat (obviously).

The “dovetail” - you will need TWO of these, they slide onto the top sides of the “top”. They are printed with their single flat faces down. They will probably fit tight enough not to need to be glued but it's probably a good idea.

I printed this on a i3 MK3S+ in CC3D PLA with the .2mm “speed” settings with 5 perimeters and 10% gyroid infill but I'm sure other print setting will work, you might have to do some experimentation.