Advice on boring Mag tube & PVC Tube

[LuxLuthor]

I'm not sure what the easiest (and a decent result) would be to enlarge both a Mag C and a 1" PVC.

The AW C Li-Ion cells are about 24mm at the widest point, but will fit in a C Mag. They are just a bit small for the inside of a 1" PVC tube (if I put that inside a D Cell Mag).

The Emoli cells I got are about 24.6mm with covered with some 1 mil Kapton tape, and won't quite fit inside a C Mag or the PVC tube.

I'm wondering if there is a reasonable way to enlarge the ID by just about 0.5 mm when the PVC or C Mag tube is about a foot long.

It seems like about a 25mm diameter with a longer shank drill bit might work if I can keep it straight.

 

[will]

The best way to do this is in a lathe.

If you are going to try to drill out the tubes, I suspect you are going to put the tubes in a vice. In order to hold them securely enough you will distort the tube to some extent. If you don't hold it tight enough the tube will most likely spin. A 25mm drill is a decent size. It will most likely follow the inside of the tubes. I wouldn't try to drill out the mag body. The plastic tube I might try.

 

[LuxLuthor]

I figured a lathe was going to be the best answer. Now....considering that I might only use it for this purpose, and how soft Aluminum is, you don't think I could get away with a 25mm bit? I'm trying to avoid buying a lathe for what would be a pretty limited use.

 

[will]

I figured a lathe was going to be the best answer. Now....considering that I might only use it for this purpose, and how soft Aluminum is, you don't think I could get away with a 25mm bit? I'm trying to avoid buying a lathe for what would be a pretty limited use.

My guess is that the mag body will be a problem. I would send it off to someone that has a large lathe. Another option might be a cylinder hone - with some rough stones and keosene to keep them from loading up.

There are probably others who can suggest something.

 

[RCatR]

1.25" pvc is a straight conversion to go from C-lion to D; you might have to wrap the outside of the pipe however

 

[LuxLuthor]

1.25" pvc is a straight conversion to go from C-lion to D; you might have to wrap the outside of the pipe however

My problem is not with the OD of 1.25" rather it is that the Emoli cells are 1 mm larger than the AW C Lion, and won't fit inside the PVC even without the wrapper on it.

 

[robm]

Could you not cut a slit down the PVC tube, and so get a bit of give?

 

[LuxLuthor]

Could you not cut a slit down the PVC tube, and so get a bit of give?

Actually, after trying a round 1/2" round rasp file, a 1" spade bit, I just dremel cut the PVC in half length-wise and will just tape it. Even a slit didn't quite give enough space.

This goes on my list as another reason to start thinking about a lathe.

 

[will]

Actually, after trying a round 1/2" round rasp file, a 1" spade bit, I just dremel cut the PVC in half length-wise and will just tape it. Even a slit didn't quite give enough space.

This goes on my list as another reason to start thinking about a lathe.

keep in mind - a mini lathe will not fit anything more that 5/8 inch through the chuck.

 

[scott.cr]

This goes on my list as another reason to start thinking about a lathe.

For Maglite work you'll probably want at least a 9x20, although I've successfully done internal work on 2C and 2D Mags with a 7x10, the real "mini" lathe sold through the various tool importers (Horrible Freight et al).

One thing about Mags I find is that they are not very straight or round; your DIY lathe work tends to be a lot more precise than mass-produced lights and it sometimes makes an ugly (but very functional) mod.

 

[Northern Lights]

I used an automotive brake hone, a couple of dollars from a used tool store and very common in autoparts stores, to enlarge a tube a small amount.

 

[LuxLuthor]

I used an automotive brake hone, a couple of dollars from a used tool store and very common in autoparts stores, to enlarge a tube a small amount.

Hmmm....got any more details about that?

 

[Northern Lights]

Hmmm....got any more details about that?

Please google images for 'brake hone' and you will get a picture. It is a very common and cheap tool that looks like a tripod, the legs are spring loaded and the "feet" are grinding and polishing stones,(interchangeble). The come in various sizes and are used with a drill, they self center, to hone out the brake cylinders on cars and trucks. Almost all discount autoparts stores carry them and if you have a used tool store around they probably have dozens on the shelf. I would use the course stones and finish with a fine. They are designed to hone steel so they clog the stones up quickly with the soft aluminum, but for less than 1mm they seem to work ok.

 

[LuxLuthor]

Thanks very much. That will work just great for my purposes. Found a bunch of selections at Amazon for reference. I owe you one! :wave:

Edit, looking around I also found this other product in various sizes also used with a drill called a "Flex-Hone" which might also be useful.

I'm gonna call them on Monday to see if they have an opinion on using it with Aluminum Maglite tubes.

 

[Northern Lights]

Thanks very much. That will work just great for my purposes. Found a bunch of selections at Amazon for reference. I owe you one! :wave:

Edit, looking around I also found this other product in various sizes also used with a drill called a "Flex-Hone" which might also be useful.

I'm gonna call them on Monday to see if they have an opinion on using it with Aluminum Maglite tubes.

One CPF thread did list the ball hone, I looked at them, expensive and usually used to coarse out a engine cylinder. They are self centering but getting the correct size is a chore. I have not seen a reply where it was tried.
There are some threads regarding these products, click the links in the posts and search cpf for hone, ball hone and cylinder hone. Good luck, LL:
http://candlepowerforums.com/vb/showthread.php?t=110748&highlight=flex+hone

 

[Dung Beetle]

I saw some Engine Cylinder Hone, and brake hone on the Sears website.

I'm not sure if I allowed to post a link. :thinking:

 

[LuxLuthor]

One CPF thread did list the ball hone, I looked at them, expensive and usually used to coarse out a engine cylinder. They are self centering but getting the correct size is a chore. I have not seen a reply where it was tried.
There are some threads regarding these products, click the links in the posts and search cpf for hone, ball hone and cylinder hone. Good luck, LL:
http://candlepowerforums.com/vb/showthread.php?t=110748&highlight=flex+hone

Besides the tri/quad boring that can be done by various members (including Northern Lights) I finally got around to using the KD Tools brake hone tool #265 & replacement stones #266 which I have not needed yet -- shown here, and with some WD-40 and a little time, I was able to cheaply (& easily since this fits in any hand drill) widen both a C mag (for Emoli cell to fit), and D cell for any AA quad pack cells to fit with this technique.

This is actually a very nice, cheap way to get some extra room. You can hold the mag tube in one hand and slide the hone back and forth. You will have to remove some of the fine metal powder a few times, and reverse direction to use both edges of the stones, but it works.