Well, the steel ring had been very stiff to move on the pipe and so, to start with, the parts were cleaned in kero. This revealed that at the bottom of the ring's grub screw there was a piece of lead, which had been put there to keep the ring from inadvertently moving. AND, to avoid marring the very fine thread with the tip of the grub screw.
How was I going to remove that pesky piece of lead?
Over lunch, I had a brainwave
There was no way to drill the thing out and tap the hole. I did not possess a tap for a 40 y. o. American grub screw.But I thought if the lead was drilled through with my smallest drill, then the surface area of lead in contact with the thread would be reduced and so would the friction, when turning the ring.
I commenced drilling after lunch, with a hand drill. Very Carefully. Very Slowly.
The entire drill fell !
Not far. Just to the opposite (internal) side of the ring. Unknown to me, the the grip of the drill on the lead was enough to turn the slug in the grub-screw-hole, until it cleared it completely and fell in to open space. All the way to the opposite side of the ring. Mission accomplished. How lucky can you get
https://www.lymanproducts.com/brands/ly ... pack-comboThe pic above is from the maker's site. The "flanged pipe and ring" can be seen on the shaft below the complete unit. The parts on the shaft are in a screwed together position. Previously, I had seen those parts in a separated condition on that same site but this time they do not appear
