Vaud, tried all the ego units on the adapter and got the same, no joy......so, i tried forcedfuel50's idea and screwed the adapter onto the the 18350 harder than I had before, and, BINGO!

works like a bloody charm!! I am chuffed to bits! Going to leave the adapter on as I'm constantly changing from DCA to Ego to 510 as my mood takes me and I've got the darned thing working the way I want it to, don't want to touch it and bugger it up again! lol
Forcedfuel50, I belive that the 18350 was made by you, is that correct? If so, Sir , may I shake your hand? It is a truely beautiful piece of craftsmanship, and I feel this
mod may last me a lifetime. My go-to ecig used to be my old Screwdriver MKII which died recently, I don't think I will be having any such problems with the 18350.
Also, do you recommend lubricating the mating parts on the
device? If so, what would your recommended lubricant be?
Cheers,
Iain