Decided to make at least one vang using a Dubro 2157 4-40 full threaded turnbuckle.

Generally I think anyone who does make their own vangs puts a left hand thread in an aluminum tube, but a couple years ago I made one by putting a left hand thread in a Sullivan 4-40 gold-n-clevis. I did not remember how I did that, but I decided maybe I had drilled the clevis out with a 3/32 drill bit and then threaded it with a LH thread cutter.

That worked very well today. It takes a bit of care and slow going to make sure the cutter does not break. I just put the tap in a vise and kept working the clevis back and forth.

After the thread is cut, the tool is still pretty tight in the hole - difficult to spin it out of the clevis - but the turnbuckle has a perfect fit.

I had limited luck at putting a left hand thread in a brass tube. It is easier with the clevis sincne it is not solid - has a split in the barrel.


Scott

I think I listed the wrong drill size. Today I used a 7/64 drill and it still was not easy to cut the LH thread. It went fine tho.

Scott

Scott, I've done it with the plastic clevis ends and a left hand tap. The trick is to have the plastic clevis squeezed in a vice as the plastic tends to just move out of the way of the tap and the result is too tight. Tap twice with the clamping on the second time at 90 degrees from the first. I also use a 4-40 Titanium turnbuckle rod available in various lengths. It is a model car suspension part. I don't have the part numbers here now but can get them if there is interest.
George