What to use for shooting rest joint

[Reggie Gerber]

Hi All
I am busy trying to make a better shooting rest out of my current tripod. I have welded two V'S on the ends of a piece of square tubing to rest the rifle in. This bar can bolt onto my tripod and can therefore be rotated from left to right. I now need to use something to be able to pivot the rest up or down and it needs to be quite stiff so that if left to stand it wont drop forwards or backwards.

What do you guys use on your bakkie rigs for this pivot point. I am trying to make my rest as small as possible as it is for day calling and can be carried around easily.

Any suggestions or pics will be much appreciated

Thanks Reggie