4 link bar question

i am building my own triangulated 4 link, and i have everything figured out on how to mount the bars and everything, the top bars are 1.5" solid round and i am using polly bushings, i put the bars into my lathe and drilled out and tapped one end so i could put one adjustable end on each bar, when i threaded the bar and put the adjustable polly bushing in it seems like there is a little play in the threads.. i did not know if anyone else has had this kinda problem?? i threaded the end in about 1.25" and there is just a little wobble on the bar end?

I'd have to pull out a Machinist Handbook, but You just don't have a tight tolerance.

1. Either you drilled the hole out to large, before you tapped it.
2. You tapped it with the wrong tap.

In any case it sounds like your threads in the bar are to small.

yes in deed ^

well i matched everything up, the bushing end has a 3/4" bolt (which i bought from suicide doors) so i bought a 3/4 tap and the tap said to drill ll/16 hole and that is what i did and i drilled the hole in my lathe so i know the hole is straight, and the threads are correct cause it screws in nice, there is not a lot of play but just a little

oh i did not tighten the jam nuts yet i think that might help out... i will let you know

you'll probably be fine after the jams are tightened. even though it is a bit loose, as long as you have atleast 1inch of the bar end screwed in, the threads should provide enough torque to not slip out.

the reason that ur threads are a little loose is because the tap drill size, which in ur case is 11/16, is actually only giving u approx. 75% thread contact. plus if the drill wasnt sharpened perfectly then the hole will be a bit bigger giving u even less. when i did mine i wrote a program for our CNC lathe and then threaded them that way to ensure a perfect fit. but once the jam nut is tightened on you should be ok.