John,
It’s a pity not to use them as you can get some really good effects. I hope we haven't put people off trying them.
These four are worth passing round, and should give people no problems.
They have very identifiable and grabbable parts as you can see from the 10m grid scaling, so can be easily moved or deleted. I’m sure there are many more which I have not found.
From left to right:
Black smoke ground - kuid:101031:60048 (smoke randomly rotates - my favourite)
Smoke Generator - kuid:225064:4010903 ( smokes vertically only)
Smokestack 13m high - kuid2:77573:24123:1 (stack partly buried for clarity, smokes vertically only)
Smoking chimney - kuid:74704:100112 (stack partly buried for clarity, smoke randomly rotates)
No Bogarting!
Cheers
Casper