# Feeler: 17670/16340 PVC adapter for bored bodies



## bstrickler (Apr 25, 2010)

Is anyone remotely interested in getting 16340/17670 PVC adapters for their bored Surefires? I know when I was running my bored 6P, sometimes I'd want to switch to 17670's or 16340's, and I was frustrated by the flickering/loss of output sometimes, because of the ID of the body being too large for the cells, causing them to lose contact with eachother or with the head/tailsprings on the light.

I ended up making a PVC adapter with my lathe to eliminate that problem, and found it quite useful, because it meant I wouldn't have to spend another $20+ on a body that I didn't really need, when the adapter worked perfectly fine.

I would be looking to charge about $10/adapter for 17670/2x16340, and if there is enough interest, $12 for 2x17500, and $15 for 2x 18650.

I would need some pre-orders for the 2x17500/17670's, so I can buy the proper supplies. I only have the stuff for 1x17670/2x16340. I can try out the 2x17500's tonight, but I don't know how well it will work with my current tooling.

PM me if you're interested in other sizes.


I am also working on designing a D36 & D26 drop-in for the single emitter XP-E/XP-G boards (current drive levels right now are about 300 and 700 ma, for long life. May make higher-powered drivers in the future.), using the Lisa optics (Ordering some 6*, 19* and 30* optics to play with, and test out with my XP-E emitters). Prices for those are unknown right now (making them on a manual lathe, so I can't quite crank them out as fast/easily as the guy's using a CNC, when I do get the designs down, and can start making them).

~Brian


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## HarryN (May 15, 2010)

Very possibly. The reason I am interested is that I gave my brother an eagletac that can take 1 x 18650 or 2 x 123, and I am sure at some point, the adapter will get lost.

If you have any interest in making a 26650 cell to D cell adapter, that would be interesting as well. My interest is for a Streamlight SL-20x project, but I assume others might use them in other D size lights. 

It would be nice if there was some method to move heat from the cells to the flashlight wall, rather than bottling it up with plastic adapters, but I don't have a clear vision of how you would do that, unless the adapter was part metal.


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## bstrickler (May 18, 2010)

When I get some money, I'll work on making the 26650 adapter, and I'll make some 2 CR123 to 1 18650 adapters starting Wednesday, if I have the time.

I haven't been able to think of a cost effective way of transferring heat from the cells, without the potential for a short, or rubbing through the plastic casing. The only option I've found is CoolPoly, and I haven't gotten the chance to e-mail them (just found them yesterday), and see if I could get a sample bar of the stuff from them, and have someone test out a CoolPoly sleeve vs PVC sleeve using an IMR cell under high drain.

~Brian


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## HarryN (May 18, 2010)

Hi, I am not sure if this helps or not, but Streamlight has an interesting approach on the SL-20x line. The original version body tube is sized for D cells, and the newer model uses a sub C pack, but the same body tube.

The way they dealt with it, was to put sort of a ribbing inside of the body tube. The cells are held in place by the ribs, but there is also room for some air movement. Its not perfect, but it is much better than a solid plastic liner.

Perhaps there is some mechanical method to cut air channels into the battery adapters to allow at least some improvement vs a solid tube?


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## bstrickler (May 18, 2010)

HarryN said:


> Hi, I am not sure if this helps or not, but Streamlight has an interesting approach on the SL-20x line. The original version body tube is sized for D cells, and the newer model uses a sub C pack, but the same body tube.
> 
> The way they dealt with it, was to put sort of a ribbing inside of the body tube. The cells are held in place by the ribs, but there is also room for some air movement. Its not perfect, but it is much better than a solid plastic liner.
> 
> Perhaps there is some mechanical method to cut air channels into the battery adapters to allow at least some improvement vs a solid tube?



That would be possible, if I had a CNC lathe, and the tooling to do that. I only have a manual lathe, and indexing tips right now.

Another possibility, using a knockoff of that idea, is to make PVC rings, and plastic spacers, so there's air pockets in between the rings.

Sort of like the levitating magnets shown here (the wooden dowel represents the batteries):






But with 2 or 3 spacers between each disc. The biggest problem I can think of with that idea, is getting the cells to stay lined up (depending on how far apart the discs are spaced, and what cells are being used), and inserting/removing the cells.


Or were you talking about something similar to the rifling in a gun barrel (but with deeper valleys)? I wouldn't be able to do that, either, except in small pieces, possibly. Nothing I currently have the money for.

First, though, I'll see if I can get some bar samples of the CoolPoly stuff, and see what it would cost for a few feet of it.

~Brian


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## HarryN (May 18, 2010)

Hi Brian,

I like your o ring / disc idea in the picture. I am not sure how you would actually implement this to keep the cells and discs in place, but perhaps there is a way to capture them with a rod on one side or something. 

I suppose in some cases, 2 or 3 of these discs could simply be epoxied to the cell. (near the ends and one in the middle) That would certainly be the simple way to make them, and be fine for my use. It might even be considered a safety enhancement by some, as it would tend to reduce the shock a cell takes when a light is dropped.

I am not sure if epoxied discs onto a cell would satisfy everyone or not. Permanent discs epoxied onto a cell would potentially limit what light you could use a particular cell in. It also fails to deal with using primaries in a light, unless someone is willing to put them on ahead of time, or just deal with the limitation of imperfection.

The Streamlight approach is more similar to deep rifling, but without the twist. (straight line flutes of sort)

The basic idea is just that it would be nice to have a way to avoid thermally insulating the cells. Exactly how you do it is of course up to you.


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## HarryN (May 18, 2010)

I just had a look at the cool poly material. That is a nice find and would make a lot of sense if the pricing is viable.


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