Right now I'm using 1/2, but because they stick out so far, the threaded shafts are bending. I have since found 1/2 heim joints with a 5/8 threaded shaft, so I will use these. Should get rid of the problem'
While on the subject of heim joints;
I'm busy building another small buggy, but don't want to use any heim joints at all. I thought about using a tie rod end for the upper and lower ball joint !!
What do you think ??