Flashlight boring for 18650s?

Hi there guys,

Another random question here, do you have any recommendations for boring a flashlight body to 19mm for use of 18650 rechargeables?

I've an old 6P original that I am contemplating building into a high-horsepower LED critter, and by all accounts, a solid 18650 would make for a suitable power source. The original body needs to be bored out, so I'm looking into who might be able to do such work. .

Thanks!
Tom

Most common answer would be sandpaper around a form. Big risk of not being centered when working and coming through wall or making it so weak it breaks. Even if centered, run the risk of making walls so thin they don't have enough strength to withstand blows.

I just use 16650s in my 6P and G2s. If it rattles just shim it with some thin card stock.

Hi there,

Hey there's an idea! Makes perfect sense to me! I might have to give that a go here! Thanks for that!

I use the 16650s as well in my lights, and they work really well. I was just thinking the extra capacity might be a good thing, and if anything would make for a little longer-lasting light too.

Thanks again!
Tom

Depending on exactly what you are trying to accomplish, there are aftermarket parts that can probably do what you want, without risking or damaging the original 6P tube.

I've bored a Surefire Z2 and a Fury with the sandpaper method, as long as you hold your drill in one hand and the flashlight in the other the sandpaper will naturally centre, wear a glove as the flashlight will get ho, remove 'O' rings to prevent damaging them.

Don't put the flashlight in a vice as you will then not be able to evenly remove the material that you want to.

Use coarse sandpaper to remove the majority and then polish with fine sandpaper.

I have two bored 6Ps. One of them is still intact. The other had the part of the body where the threads are snap off under very light and normal use for a year.

I would just buy a Malkoff MD2 body and leave the 6P stock personally.

Tachead said:

I would just buy a Malkoff MD2 body and leave the 6P stock personally.

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Does MD2 body accommodate all 6p drop-ins?

Sorry, should elaborate. I thought the Malkoff drop-ins were smaller in diameter than the surefire drop ins?

euroken said:

Does MD2 body accommodate all 6p drop-ins?

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I think most of them but, you had better ask the guys in the Malkoff thread as I have never owned an MD2.

I have seen problems with the DIY-bores in that a 'ledge' isn't retained where a P60 drop-in would set, with resulting electrical connectivity issues on occasion.

Either a professional boring job to use the large-capacity 18650's (for a heavily-used light to take full advantage of same); or just keeping the stock inner diameter & running the new 16650's for a cost-effective, occasional-use setup.

euroken said:

Does MD2 body accommodate all 6p drop-ins?

Click to expand...

Tachead said:

I think most of them but, you had better ask the guys in the Malkoff thread as I have never owned an MD2.

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You need VEN. If he doesn't own the complete list of MDX compatible drop ins, he can at least enumerate succinctly.

Boring for 18650 has been on my mind lately, since it always seemed like obviously a great idea: the best advances in cell chem seem to be with 18650 (highest energy density of any cell format I'd bet), it is a super popular format found everywhere, so should be available a long time and easy and cheap to start a collection of them.

The benefits seem to be overwhelming until you recognize 1) that the differences in capacity between the 18650's you'll be able to use safely (the largest capacities might be excluded because their diameter is slightly larger) and 16650 is only about 500-700mAh (about as much in a NiMH AAA battery) 2) threads are at immensely greater risk of cracking or snapping off completely.

Still it is a cool idea, and just one of the ingenious ideas that some flashaholic modder first thought-up. I have one bored E2e that came to me like that, and the bore is annoyingly not quite center, larger 3200-3500mAh cells get stuck, so won't fit. Also, I have (through repeated clumsy dropping onto concrete) broken the threads of a non-Surefire 18500 E body. I think P Series might leave more material for threads after boring than E Series, though this thread is the first I have heard of a P Series bore failing. But I think better than boring is to find a fivemega body, or Malkoff, LeeF or even SolarForce that is 18mm-cell ready, set your original aside, keep it in good shape.

Another new problem is disconcerting... I read a thread at CPF not too long ago complaining 16650's were no longer going to be made, and they do seem to have become harder to locate, out of stock lots of places (like Illumn). What's the favorite most reliable source for the (rewrapped is ok) authentic 4.35V Sanyo UR16650ZTA (best protected and limited to 4.2V) right now?

Can't help you with US suppliers but i know few EU dealers that ship worldwide. Nkon.nl, ecoluxdirect.co.uk and akkuteile.de

night.hoodie said:

Another new problem is disconcerting... I read a thread at CPF not too long ago complaining 16650's were no longer going to be made, and they do seem to have become harder to locate, out of stock lots of places (like Illumn). What's the favorite most reliable source for the (rewrapped is ok) authentic 4.35V Sanyo UR16650ZTA (best protected and limited to 4.2V) right now?

Click to expand...

I grabbed a couple from Illumn a couple of weeks ago. Craig said, not specifically about the ZTA however, that he was hoping to get a shipment soon. I would shoot him an email and ask👍.

night.hoodie said:

16650 is only about 500-700mAh (about as much in a NiMH AAA battery)

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No idea where that number is coming from, might like to correct that perhaps. Also, any comparisons to 1.2v NiMH should really be done in watt-hours.

Modernflame said:

You need VEN. If he doesn't own the complete list of MDX compatible drop ins, he can at least enumerate succinctly.

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I have had no issue with the MD2 body, the actual issue is with the ring(locking). EDC+ and sportac fit(surefire fit, not the squarer shaped body for solarforce etc).
Pics say a 1000 words, this is the EDC+ triple, next to an M61(note the same shape shell, so fit the locking ring)


Pic of the ring, 3 drop ins,m61/sportac/quad with a straight edge at end, not chamfered.

Pic to show how the ring will not fit over the end of the drop in


How it should look


Hope that makes sense.

So a simple mod to the ring will accommodate the a55 end of other p60's. Deburr tool, dremel, anything to open the inside of the ring up a little.



How it should look


If not the head will not screw down onto the body enough, hence not making contact...........no worky

Triples work well if those are your cup of tea


Not much point in a quad, too much covered on optic. Of course using a head with a wider opening would be prefered



So all my drop ins are compatible, its the actual locking ring that may/may not need a little tweak to sit better.

Cheers

Hey Ven, do you know anything about Pflexpro drop-ins? Do they fit the MD2? What about the VME? Thanks.

Tachead said:

Hey Ven, do you know anything about Pflexpro drop-ins? Do they fit the MD2? What about the VME? Thanks.

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Hey there, i dont own a Pflexpro, but confident enough to recommend. As for fitting with the MD2, its just the locking ring that could be the only issue. EDC/malk/sportac shells fit with no mod to the ring. The other design/style requires the ring to be opened up a little.

The inner section here to fit over the p60 end.


Not sure on the VME as i dont own one.

As the head of the MD2 is pretty much hollow, the narrow closing on the front is just a thin lip. Any p60 will fit in the MD2 head, just the tail end is a variable on the p60 shells/drivers.

Ok, thank you for all the info sir, I appreciate it👍.

Welcome, any time