Modified OMS Canister

[350xfire]

My first modified OMS canister. This canister will fit up to 10 18650 batteries and makes a nice alternative to a high dollar Delrin canister. I added a second o-ring on the lid, a switch/boot, gland, switch guard and a lid cover. Used white Delrin since I already had some. OMS rates these to 660' and I have tested in my pressure pot for over 2 days at 265'.

 

[AJMichael]

Nice stuff!

 

[jspeybro]

now that looks like something I can make nice work and thanks for the idea!

I assume this is the BCA298 cannister?
So that would be a 50.8mm ID, 60.45mm OD and a 208mm overall length, which is perfect for what I had in mind.

What is the thickness of the lids? (enough to make a thread for the gland?)
How does it close? is it just a threaded lid?
Can both lids be opened?

perhaps you could show a better picture of the lid?

 

[350xfire]

now that looks like something I can make nice work and thanks for the idea!

I assume this is the BCA298 cannister?
So that would be a 50.8mm ID, 60.45mm OD and a 208mm overall length, which is perfect for what I had in mind.

What is the thickness of the lids? (enough to make a thread for the gland?)
How does it close? is it just a threaded lid?
Can both lids be opened?

perhaps you could show a better picture of the lid?

Yes, BCA 298... Yes, the thickness is just slightly thicker than the Agro gland threads so enough there. Be carefull and don't overtighten. I used a bit of black silicone around the threads as a secondary safety.

Lid is threaded and only takes about 2.5 turns. Yes, both lids can be opened.

I have had up to a 9 cell 18650 pack and works great. I don;t think 10 will work unless you have a very small connector. I use the Andersons which are a bit long. With 9 cells you can tuck the connector on the side. I used a 4 on 5 set up with 5 being on the bottom. By having 4 cells on the top you have a nice tuck in place for the connector oin the side. Wire twist is not an issue as the pack turns when you thread the lid on.

Really a slick set up. Now, if you want the battery pack to fit in the bottom lid you have to open it up and I would not use more than 4 batteries in the lid. I am not sure whether it can be opened up enough for 5 18650 yet. If it can be opened up for 5 than a 10 cell would work with no problems.

 

[jspeybro]

if I understand you correctly, the batteries sit on top of the bottom lid, they do not slide in unless you only use four batteries?

maybe you could make the wire between the top lid and the connector a little longer than the hight of the cannister and tuck away the connector in the bottom lid. you would have no need for the batteries to twist together with the lid, just turn it upside down, open the bottom lid, disconnect and charge the batteries. would this allow to use 10 batteries, even with a moderate connector?

Johan

 

[350xfire]

if I understand you correctly, the batteries sit on top of the bottom lid, they do not slide in unless you only use four batteries?

maybe you could make the wire between the top lid and the connector a little longer than the hight of the cannister and tuck away the connector in the bottom lid. you would have no need for the batteries to twist together with the lid, just turn it upside down, open the bottom lid, disconnect and charge the batteries. would this allow to use 10 batteries, even with a moderate connector?

Johan

Yes, that will probably work with 10 batteries.

 

[SmokedCPU]

nice can dude !!
still dont fit for my silly prototype ....


need to power CMB 360 at 6a for 2.5hours ....
i'll need a crazy canister ... maybe an old 80CF with a lid
Somebody have an idea ?
Ill run on H6CC so limited to 5s 21v ... i was thinking of two 5s 5Ah in parallel, but its crazy big .... too many D cell 10Ah

I'll not have it on time to dive on Empress of Ireland on St-Laurent... it dont matter !

 

[350xfire]

nice can dude !!
still dont fit for my silly prototype ....


need to power CMB 360 at 6a for 2.5hours ....
i'll need a crazy canister ... maybe an old 80CF with a lid
Somebody have an idea ?
Ill run on H6CC so limited to 5s 21v ... i was thinking of two 5s 5Ah in parallel, but its crazy big .... too many D cell 10Ah

I'll not have it on time to dive on Empress of Ireland on St-Laurent... it dont matter !

lol! Yeah you can get 10 18650 in there. You can do a 3.5" canister with 10 D cells.

 

[DIWdiver]

nice can dude !!
still dont fit for my silly prototype ....


need to power CMB 360 at 6a for 2.5hours ....
i'll need a crazy canister ... maybe an old 80CF with a lid
Somebody have an idea ?
Ill run on H6CC so limited to 5s 21v ... i was thinking of two 5s 5Ah in parallel, but its crazy big .... too many D cell 10Ah

I'll not have it on time to dive on Empress of Ireland on St-Laurent... it dont matter !

Funny you should mention the AL80 with a lid, as that is exactly how I built my pressure pot. For the right price, I'll send it to you.

Seriously though...

The '360 has typical forward voltage of 14.4V. At 6A, 2.5H, you need 216 watt-hours. Add 10% for losses in the driver, and you need 238 W-H to run for 2.5 hours. The pack will not provide 21V for most of the discharge time. Typically folks figure on an average of 3.7V/cell, or 18.5V in this pack. Thus the pack would provide only 185 W-H even when brand new, giving a run time of less than 2 hours.

I looked at the H6CC spec sheet, and it doesn't even have curves for 4 leds. I'm guessing however that you will need 16-18V to get 6A into your 4-led '360 module, which means the light is going to begin to dim before the batteries are fully discharged. You might want to ask about the performance of the board at 6A/4LEDs before you spend a lot of time and money building and are disappointed in the results.

Alternatively, you might ask if the input voltage can be pushed to 25.2V, which would allow you a 6s pack, which would give you closer to the performance you're looking for.

D

 

[DIWdiver]

My first modified OMS canister. This canister will fit up to 10 18650 batteries and makes a nice alternative to a high dollar Delrin canister. I added a second o-ring on the lid, a switch/boot, gland, switch guard and a lid cover. Used white Delrin since I already had some. OMS rates these to 660' and I have tested in my pressure pot for over 2 days at 265'.

Cool idea. I can see a lot of folks doing this if they don't have the tools/skills/cash to scratch-build a can. If the size is right for you it's hard to argue with the price!

I tested my light to 500', but also tested at 10', 30', 100', and several 0-500' excursions. In my experience most lights flood at the beginning or end of a dive, in shallow water. This makes sense, because when you get them deep, the pressure pushes the o-rings harder against the walls, making the seal better.

And no, I don't plan to dive to depths like that. It's purely for bragging rights, and because I could.

 

[350xfire]

Cool idea. I can see a lot of folks doing this if they don't have the tools/skills/cash to scratch-build a can. If the size is right for you it's hard to argue with the price!

I tested my light to 500', but also tested at 10', 30', 100', and several 0-500' excursions. In my experience most lights flood at the beginning or end of a dive, in shallow water. This makes sense, because when you get them deep, the pressure pushes the o-rings harder against the walls, making the seal better.

And no, I don't plan to dive to depths like that. It's purely for bragging rights, and because I could.

Thanks

 

[jspeybro]

Cool idea. I can see a lot of folks doing this if they don't have the tools/skills/cash to scratch-build a can. If the size is right for you it's hard to argue with the price!

That's how it is with me. I hesitating to buy a lathe, but until then, this looks like the perfect sollution.

350xfire, can we have a better picture of the modified lid where we can see the o-ring modification?

thanks,
Johan

 

[350xfire]

That's how it is with me. I hesitating to buy a lathe, but until then, this looks like the perfect sollution.

350xfire, can we have a better picture of the modified lid where we can see the o-ring modification?

thanks,
Johan

Johan:
The additional o-ring does not require a modification you simply add an NBR79 2.114" (53.7mm)ID x 0.070" (1.78mm) o-ring to the outer part of the lid. I hope you can see it on these pics.. Very easy to do and there is a nice little groove on the lid to allow for this!

This is another one I am working on with black switch guard. Still have not fabricated the lid cover.

 

[jspeybro]

thanks for the extra info.
what is the lid cover used for? to make it stronger or just a finishing touch to hide the switch?

 

[350xfire]

thanks for the extra info.
what is the lid cover used for? to make it stronger or just a finishing touch to hide the switch?

The cover hides the computer programmable electronics, the solar powered charger and the reid switches, mosfets and muffler bearings , magnets and flux capacitors to make the entire system work... Oh, and it is held in place with custom machined titanium alloy screws....

OK, not really just to give it a nice clean look!!! Nothing special just looks. Oh, and what I do is to machine it to be a slight press fit and use cyanoacrylate (some type of super glue) to hold it in place. Delrin doesn't glue together worth a crap so this way if you ever have to take it apart you just gently pry with screwdriver and it comes off!
The switch guard goes on with #6 screws that are 1" long. You have to be careful and make the switch guard tall enough to make sure you don't pierce through the lid. I think about 0.75" is about right. You also need to make the switch guard short enough to be able to gturn the light on and off confortably but still provide good protection to the boot.. There is a fine line...

 

[SmokedCPU]

i had found this canister some time ago and did not pursue research on it.

your can look nice dude !

Only one thing is missing !
Make a batch of epoxy with GID podwer and then put it all around.
if somebody is wearing it in his back, will work as a strobe / back marker.

 

[waterloodiver]

very nice work

 

[350xfire]

Thanks

 

[H20doctor]

Very nice ...

 

[Klem]

"Looks like a bought one!" ['Down-under' translation...It looks good]:thumbsup: