New builder, can light parts list help

[Willis]

Hi -
Been reading quite a lot, trying to avoid the inevitable questions answerable by search.
Been diving for a while now - I dive mostly in Eastern WA in the US, and make it to the Puget Sound whenever possible. This means that 4 meters of viz is a good day. So - as my first can light I was thinking of shamelessly copying Packhorse's 4xXRE monster.
So I've put together this parts list:

# Item Source Notes
4 CREE Q5 LED DX SKU11022
4 aspheric lenses - 21x7.3mm DX SKU 13903 - 10 pack
1 Mag Light host old stock
12" PVC for spacers Home Depot ID 16mm - 1/2" SCH40
1 tube thermal glue DX SKU 4579
6 Li-ion batts - protected DX SKU 20392 - 2 pack
PVC for canister Home Depot 3"
2 Latches for Canister McMaster Carr PN 1794A43
Canister O ring McMaster Carr 3-3.5"x1/4" buna n PN 9452K237 - 5 pack
Hose Clamps to secure can Home Depot
1 Driver - 2.8A KAIdomain SKU S005296
2 cable glands McMaster Carr PN 6907K12
10' hookup cable - silicone jacketed Home Depot 16gauge 2wire
power connector old stock from auto bucket
AL for heatsink old stock
thermal paste DX SKU 4593
1 reed switch Mouser M PN 876-KSK-1A81-0510
1 magnet for reed switch McMaster Carr PN 5902K53
1 MOSFET for switch Mouser M PN 512-FDP80N06
1 tube epoxy old stock
3 battery charger DX SKU 4151 - 2x charger
Mag bezel/lens Oring McMaster Carr PN 9262K207 - NBR 70 48mmIDx2MM 25pack
Tail cap Oring McMaster Carr PN 9452K88 - NBR 70 124 - 100pack
1 lens - 52mm for host DX SKU 25231 - 5 pack
1 lens - 50.8mm for step DX SKU 10647 - 10 pack

Sorry about the formatting, copied from spreadsheet.
Was going to build a canister out of 3" PVC with oven flattened sections for top and bottom. Reed switch driving a MOSFET driving the Kaidomain cheapo driver, for now.
I don't have a lathe, but I do have some 1/2 inch aluminum plate I think I can get a usable heat sink out of. I was going to glue the lens spacer PVC to a backer board and turn the sections down in a drill press. Tedious certainly, but I've got more time than money - and often more time than brains.
Any thoughts on this list - either parts or suppliers? I've got a few other things I need to flesh out the Mouser order. Old Stock means I've got it laying around.
One thing I'm not too familiar with is battery packs - was going to make an easy to disassemble 3S2P pack for the driver, hoping for ~5 hours burn time. Would charge each battery separately to try and keep them balanced. Again, more time than money. I'll probably buy parts to build 2 as my dive buddy could also use a can light - I'll charge him for my time... :)
Does this seem about right?
Thanks in advance.
Will

 

[gcbryan]

Hey, I thought I'd comment since no one else has! I live in Seattle. I assume you also dive in Lake Cour d'Alene?

Your list looks pretty complete to me...I've never built a cannister light however. I'm sure others will be along to comment. Be sure to post pictures of the finished project!

If you run into any problems and need help I'm sure you will get more responses.

 

[Willis]

Hey, I thought I'd comment since no one else has! I live in Seattle. I assume you also dive in Lake Cour d'Alene?

Your list looks pretty complete to me...I've never built a cannister light however. I'm sure others will be along to comment. Be sure to post pictures of the finished project!

If you run into any problems and need help I'm sure you will get more responses.

Thanks!
Yep, I'm in Coeur d'Alene about once or twice a month, if not more. One of the more interesting dives I've had there is the salmon run around the end of November - hundreds of Kokanee going crazy. I've never been run into by so many fish. Also the Spokane River, Lake Pend Oreille, and the numerous other lakes around. Of course, any chance I get the saltwater to the west has us beat here.
Yep, I've been reading quite a bit to try and get a comprehensive list together. I've built quite a few similar things - automotive electronics etc, but never a light, and never submersible gear. Also not very up-to-date on modern batteries. I've got enough respect for lithium, but not as much understanding. I'm thinking my 3S2P pack ought to provide about 4+ hours burn, eh?
And a bit more reading - I've decided that perhaps the better 2 battery charger is this one by DSD. Much as I'd love to shell out for a nice one, cash dictates otherwise since I'll need 3.
So the two main questions I had were the battery pack - does it sound about right, and the lenses - will gluing the two lenses create a stepped lense with enough strength for 50+ meters?
Will

 

[gcbryan]

Thanks!
Yep, I'm in Coeur d'Alene about once or twice a month, if not more. One of the more interesting dives I've had there is the salmon run around the end of November - hundreds of Kokanee going crazy. I've never been run into by so many fish. Also the Spokane River, Lake Pend Oreille, and the numerous other lakes around. Of course, any chance I get the saltwater to the west has us beat here.
Yep, I've been reading quite a bit to try and get a comprehensive list together. I've built quite a few similar things - automotive electronics etc, but never a light, and never submersible gear. Also not very up-to-date on modern batteries. I've got enough respect for lithium, but not as much understanding. I'm thinking my 3S2P pack ought to provide about 4+ hours burn, eh?
And a bit more reading - I've decided that perhaps the better 2 battery charger is this one by DSD. Much as I'd love to shell out for a nice one, cash dictates otherwise since I'll need 3.
So the two main questions I had were the battery pack - does it sound about right, and the lenses - will gluing the two lenses create a stepped lense with enough strength for 50+ meters?
Will

You should be fine on those two points...4 mm should be OK for a 52mm lens. I have a dive light that is 52 mm and the lens is only about 2.5mm. I haven't heard of any lens breaking at the 150 fsw range for this light however it isn't an optimum size...4 mm would be good. I have a smaller backup light that is 30 mm in diameter and it's 6 mm thick which is overkill at that diameter and depth.

If you want your light to be robust down to 300 fsw then at 52 mm diameter 6 mm would probably be even better.

You could get 4 hours run time with 4 batteries. My dive light uses a MC-E which is a quad die so it's not much different than what you are doing. It uses (2) 18650 li-ion (I like Trustfire 2500mA) and gets about 2 hours on high.

There is a big difference between static and dynamic pressures so some over engineering is good.