"Borring " a torch tube Questions

Ive heard this mention many times

If i were to take this path what machine do i need to have to complete this task.
As ill obviously have to go to a factory for this .

I have an m3 body im looking into borring to accept 18650s rechargables.

How much mm should they bore to accept the rechargables 18650s

thanks

I bore using a dedicated reamer @ .734" (18.6mm) I dont have the stock ID handy, I just bore away...

You can bore the body yourself if you're up to it. All you need are : a power drill, a wood dowel, sandpaper of various grit, and a vice to hold the light while you bore it out. From my experience boring out my C3, you'll most likely be looking at a 3-4 hr job.

highorder said:

I bore using a dedicated reamer @ .734" (18.6mm) I dont have the stock ID handy, I just bore away...

Click to expand...

Where can I get a reamer this size?

The fastest and straightest job would be done on a lathe. The workpiece (aka flashlight tube) rotates while a stationary cutter is advanced into its ID. A precision adjustment is made to gradually increase the inner diameter.

Highorder mentioned using a reamer... this works too. Even though I have a lathe (as does Highorder), sometimes if you get a light that won't fit the lathe a reamer is the next best thing, and cheap. Reaming is a lot of work though, and it's easy to damage the light because it's easy to over-expand a reamer (by accident) and then it can dig into the work and gouge it.

18650's are too long for the M3's body.

You could buy This instead of altering your current light, and it will fit two 18650's unlike a M3 body.

have (let) done this for some lights now.

easiest and quickest way is to use a lathe.
The shorter the light the better because else the "knife" gets too long and starts to swing (ugly looking, unpredictable outcome).
A way is to turn the light around and cut in from the other side also.

As I have no lathe, I just went into a machine shop, costed me € 5,-- for "coffee".
Much better than the hours to be spent hand rubbing (and this wont give nice, round results. There now is just under 1mm body material left, impossible to do such by hand)

I haven't tried it, but I imagine a brake cylinder hone would do the job fairly well.

I have enlarged a D-maglight using Lye, but wouldn't recommend it unless you really understand what you're doing.