One of my very small collection has 3 x 18650 in this configuration and the resulting diameter is very hand-friendly.
Following
Good tip! I usually find myself measuring once, cutting twice, just to find the darn thing is still too short 
Go Go Go!!! If anyone can do this it is YOU!!!
Anxious to see the end result!!
TL
The Courui D01 has a tube holding 3 cells.
I have seen mods where two of those were used for the exact setup you want. (And it has a big reflector as well)
So this could be a starting point?
Steve,
, but of tears joy and then a big 
.
Very kind of you and I hope it is for the contest. I am touched deeply by your doing this and it is much appreciated. I always wanted to see a nicely finished light done properly for the LUM 5-90 and the XHP70. They make a thrower that kills anything in the way, especially at 10 amps or more. I am sure Richard will make you a great driver for it.
Remember, I love Knurling and polished rings. 
Justin
Thanks for the comments guys. Yes I do stuff up measurements. I dont know who let the cat out of the bag but thanks. :person_facepalming:
The light will hopefully run on nine cells so l’d need three battery tubes joined together if I was to use battery tubes from other lights which would be to expensive for my meagre budget. I think what I will do is drill three holes with a couple of mm’s between each hole in tube around 110mm long and join them together to make one tube. On the other hand one tube could be 2 cells long and the other one cell long. That would allow it to run on either 6 cells or 9 cells. Decisions decisions. 
Justin it warms my heart to see you here. 
Hopefully I can make this just a little different that I can incorporate the OL lathe technique (but I’d have to use my lathe ) and a few other ways of doing things you are famous for into this light.
I’m sure whatever you build will come as a big surprise Steve.
Updated 27.6.16 in the OP.
It already looks great. Skills!
I’m so happy to see that lathe cranked up again.
Cranked up again by a cranky old fool. 
Its cranked up quite often. I like making scrap metal.
I would hardly call this light a bit of scrap metal :laughing:
But I guess you haven’t actually used any of the parts yet :zipper_mouth_face: :laughing:
AWESOMENESS in the making!! MRsDNF, are the cells going to be permanently connected together, are they going to be 9 separate cells being dropped into the battery tube, or are you making a battery holder thingy?
Reversed.
:+1: I have no idea what this means but yep, I agree.
Working on 9 single cells. 3S 3P. In my mind the battery tube will be semi permanently attached to the head with a removable tailcap.
See post #2 plus your build direction.
It hit me an hour after I posted. Please be gentle with me. 
That’s about how long it took me to think of it too.
Super good looking work sir! If that hack saw is looking for a new home, I’ll send you my address!!! Every time I see that thing, I like it better. I’ll send you TWO horizontal bandsaws for it!! Ok 3. Well… OK… FOUR! :innocent: I would like to put that right in the middle of our shop as a showpiece.
Looking forward to seeing the finished lights. I found it interesting the order you build the parts in. Keep posting!!
TL