In message , Bill Wright
writes
wrote:


I do need some friction but it may well be by tightening a wing nut or
similar, the chances of getting it just right otherwise are negligable.

I had this problem. I made 30mm dia rubber washers from 1/16" rubber
sheet, and sandwiched each of them between smooth 35mm washers. One of
each pair of washers was tack weled at the very edge to one arm and the
other of the pair to the other arm. I adjusted the tension then set it
by locking two nuts together. This was for something in frequent use
and it has stayed OK for many years.

On a smaller scale I have just made some adjustable brackets for the
headlights for my wife's disability machine. Since these would not be
adjusted often I simply used nuts, bolts, serrated washers, and locktite.

My desk lamp has the provision sought. Plastic tubular *T* with a double
yoke trapping the T top. The leg fits into a split sleeve which is
itself retained by a slot in the lamp arm.

I guess this was purpose made for Anglepoise so not much help to the OP.
--
Tim Lamb