Home made "life capsule"

I see this life capsule for $40.Its a nice piece but not something I would spend $40 on,so I got to think'in what could I make to carry a few bucks,pills or whatever and hang on my keychain?

First I thought of a 1/2 inch length of copper pipe,solder a cap on one end and use a pin of some sort to hold a cap on the other.

Then it hit me! Cut down a mini mag! Ok walmart was selling them for $6.96,since most already own one replace it with a new one for 7 bucks.take your old one cut it to length,and make a plug for the cut end.A dowel about 1/2 inch long sould do it along with a little liquid nails and maybe a small screw.The tail cap end already has an "o" ring along with a hole for key rings or cord!

These may not be for everyone,but if you want a way to carry small things or some rolled money,keep them dry and protected from being crushed might just be the ticket.

I have been thinking of doing just that! But I wanted to tap the cut-down end and use another tail cap. Don't have anything but a drill press to do this with so I haven't figured it out yet. Anyone with better tool knowledge? What do I need to do this machining?

miniMe,

You can do this by hand easily. All you would need would be a tap set, or just the tap and a tap wrench for the size of the tube and correct number of threads to match the end cap. You can buy taps at Sears or any number of places and they are fairly simple to use.

Let us know how it goes...

Greg

Minime:

A small pipe cutter, and a tap and dye set should do it. The problem is that the tap set will set you back some $$$. Do you have any contacts that are plumbers, mechanics or machinists? They may have the basic kit and possibly the taps to get to that size. If all else fails, call your local high school and see if they have a metal shop. Sometimes a shop teacher will do a small job like this for you.

For convenience you might want to consider using a short bolt or allen screw for the plug end. This will be one less thing to worry about and will give the machinist a target for size and thread type.


Chris

Sure - we've yakked about this before. After I eat dinner I'll take some measurements and tell you what will work. Personally, I would just machine duplicate threads and turn a hollow threaded cap, but I understand about not having an engine lathe. What I'll see if doable is to tap for a common SAE or metric bolt size - since you have a drill press you could partially drill out (hollow) a cot-off bolt.

Another thing you can do with your drill press is to chuck up a scrap of aluminum rod and "turn" it with a file - slow and careful - until it fits. Cut-off while chucked and spinning with a hacksaw, epoxy in the end, cross drill and pin so it's secure against shear, and file/sand smooth and radiused on the outside after epoxy sets up. You'll need to keep your file card handy as the aluminum will pin (clog) the file quickly - if you load the teeth with chalk first it's not as hard to card the aluminum out of the teeth.

Dinner shout just came down - I'll post dimensions later tonight.

Tom

Saw Tom's post after i measured this so i hope he checks my measurements. The mag plug is 5/8 and appears to be a 28 thread pitch which is non standard. MSC has one listed (old catalog price about $30). Checking the bore of the body it is close enough to the correct drill size for 5/8-18 this should be available at a local hardware store for less than $6. The problem with using a standard size is finding a pretty bolt that will suit your purpose. The closest thing i can think of is a socket head cap screw, but the head is still going to be bigger than the body of your mag. You can also take a scrap of aluminum and turn it down the way Tom suggested and die cut threads on the end, but this will be time consuming and you will have to spend more money on tools, which isn't always a bad thing. Let us know what you decide to do. HTH

I picked up an 1/2" OD aluminum tube at the hardware store, 3 foot long for less than $5. I plan to try to cut some threads in the ends and see if I can get a plug to screw in.

OK - sorry it took me a while but was helping #1 kid with some college homework.

Bottom line is that you can probably do this with off-the-shelf ANSI stuff and off-the-shelf regular hardware-store Unified Metric stuff. By the way, 5/8-28 is a defined, albeit uncommon, thread size.

Short versions:

1. USA: Use a 9/16" drill in the end you want to thread. It would be much better to bore in a lathe or ream. Run a standard UNF tap in: 5/8 - 18. With decent quality drill and tap and care, you should get about 87% thread, which is pretty tight. Wall thickness at bottom of internal thread will be about 0.040", which is pretty close to what the factory leaves at the tail cap end. Cut and file a good quality 5/8 - 18 bolt, file a lead (taper the first thread smaller), and turn it in. Don't plan on using this end to open the capsule because a) it's potentially a pretty snug thread and b) galvanic corrosion between the steel and aluminum will weld it in (you can use a cadmium plated bolt but I would NOT - cadmium is very toxic. Try automotive bolts if you want a good galvanized 5/8-18 bolt and forget about using junky "home improvement store" bolts. You can TRY to get a nylon bolt from your local hardware stores - that would be much better than a steel bolt for this purpose. [You may use a 37/64" drill for about 75% thread and that will hand-turn easily enough] Rummage the hardware store for a standard O-ring to make this end more water tight or - my suggestion - epoxy the darn thing in place. NOTE - it is going to be darned difficult to "ream" this out with a twist drill bit, so be careful!

2. Metric: Well, this really would work perfectly fine with a 15mm x 1.0mm bolt (no drilling or reaming) BUT as you may know, that is NOT a standard size - no such thing as a standard 15mm bolt. (At least, not commonly available.) All these SI suggestions should result in a 75% thread. But a 16mm x 2mm should work and no drilling should be required, based on the inside diameter of three samples here. You can run a 14mm bit in the end you wish to thread, just in case. Better alternatives would be a 16mm x 1.5 mm (use a 14.5mm drill or reamer) or best, a 16mm x 1.0 mm (use a 15mm drill bit or reamer). Frankly, I'm not very comfortable with the 16mm x 2.0mm solution, though it should be OK. Same comments as above, substituting an appropriate metric bolt and again, BE CAREFUL if you use a twist drill bit.

BOTH: WD-40 or ATF (automatic transmission fluid) will work OK for a cutting fluid for both drilling and tapping. Use plenty. Aluminum galls easily and can be "gummy", even in heat treated alloys.

THE REST OF THE STORY:

I suspect that the samples that I have are made from a standard size 6061 T6 aluminum tubing stock, although they MIGHT be a slightly customized extrusion. By way of example: One supplier's standard sizes includes a 6061 T6 tubing with OD 0.750" ± 0.004", ID 0.584" ± 0.004", wall thickness 0.083" ± 0.004" The samples I have were very consistant in OD: 0.710" Basic wall thickness ranged from 0.078" to 0.080", and you can do the math on the range for ID. The wall thickness (measured at thread crest height) is less, of course - look carefully inside your mini-mag to see what I'm talking about or do the math on the threading diameters. I also note that the threaded portion has VERY consistant wall thickness, which I expected.

The end caps are very consistant in major diameter: 0.620" And I agree that the thread is probably 28 tpi, although it COULD be 27 tpi (standard thread for 1/8" pipe) - not enough threads on the cap for me to be certain and I am way too lazy to use my thread wires and micrometer for this measurement - I just use thread gauges to check the pitch.

I think these are CNC machined from standard 6061 T6 aluminum tube and that is why the dimensions are so consistant on the machined portions and why there are slight variations on the un-machined ID.

Quick note for the thread-comparison-impaired: 28 threads per inch (tpi) is close enough to 0.90mm thread, so this is pretty fine for a 16mm "bolt". 18 tpi is about 1.4mm thread - call it 1.5mm. 11 tpi, the standard coarse size for a 5/8" bolt, is about 2.3mm thread.

16mm is about 0.630" and 15mm is about 0.591" - recall that the factory plug is a precise 5/8" minus the radiused or flat tips on the thread tops for an actual diameter of 0.620". So a 16mm bolt will leave slightly thinner walls at the bottom of the internal threads than the factory end cap - about 0.040" vs an approximate 0.045" - not enough to be concerned about.

If I just had to do this and I didn't have a lathe, I think I would lean towards the 16mm x 2.0mm as this is should require no drilling or reaming. My second choice would be either 16mm x 1.5mm or 5/8 - 18, using appropriate drills or reamers (14.5mm or 37/64 for the 16mm and 9/16 or 37/64 for the 5/8"). The closest readily available solution over-all to factory would be a 16mm x 1.0mm using appropriate drills or reamers (15mm or 19/32).

Other's comments about headsize is correct - you will want to reduce the diameter of a hexhead bolt substantially (chuck bolt in drill press before trimming length and carefully use a file - if you bought a grade 8 bolt, you're gonna be there a while!) A 5/8" slotted fillister head would not be too bad - head OD is about 0.827" - 0.875" A slotted round head is huge (0.944" - 1.000" but due to shape fairly easily reduced. Forget truss head - monsters. Pan head also very big. Eyes too tired to look up socket head diameters.

So... I would NOT use the head of the bolt. After you thread the body, run a bolt in finger-snug, cut it off a bit long, slot the end with a hacksaw to suit, and file edges smooth. Remove with a screwdriver. Put epoxy or RTV or thread locker on it, run it back in with a screwdriver, and let it become permanent.

And with that in mind... I go back to my previous post: Epoxy in a short piece of aluminum rod. Cross drill and drive a pin thru for belt-and-suspenders approach. If you like, drill and tap the center of the plug for a small eyebolt (threadlock or epoxy it in) so you can attach this end to another a key ring instead of the factory end. This just isn't worth the work to make a threaded plug IMHO.

Long post, eh? I could have machined up a couple in the time it took me to peck this out...

Let us know what you do and how it turns out, please!

HTH,

Tom

For about the cost of a min-mag you can get 36" of 6061 T6 Aluminum tubing - essentially the same as what the mini-mag appears to be made from. See on line metals here.

Tom

Well, If I don't drill holes in my fingers first I can learn to become a machinist by just reading your posts! Thanks for the detail! I really value all the knowledge you shared.

What are the objections to using PVC pipe, end caps, screw caps, etc.? Are we expecting this to be beaten up beyond the strength of PVC?

There is an aluminum weld rod product that can be melted with a propane torch; I picked some up at a outdoor sport show a while back. I think I will try to cut an aluminum plug from some flashing and weld it into place. I let you all know if and how it works out. Pete

Maybe I am missing something here, but couldn't you just buy a Mag Solitare and strip all of the guts out of it? You would end up with a little single diameter alum tube with the tail cap on one end and nothing inside all the way to the lens, which you could probably replace with some non-breakable substance if you wanted...

<img src="images/graemlins/confused.gif" alt="" />***Maybe I am missing something here, but couldn't you just buy a Mag Solitare and strip all of the guts out of it? ****

Where's the fun in that? <img src="images/graemlins/grin.gif" alt="" />

Actually I was thinking just that with a mini-Mag sized light. Remove the head, seal the end with a disk of cardboard, and apply a nice thick coat of JBWeld over the end and threads. After it dries it can be sanded smooth no sweat. It might not look as cool as a fancy, machined plug, but it should serve just as well unless you really have to have access from both ends.

Ed

Hey Pete, i didn't have much luck with that stuff. Didn't spend enough time with it. But i have talked to a few people that have used it successfully. It works more like solder than "welding" make sure you clean the area very well, a stainless steel toothbrush is the recommended cleaning tool. Don't melt the substrate metal you just want to get it hot enough for the rod to flow. Aluminum doesn't change color as it heats up the way steel does, it goes from being satin looking to being shiny and then turns into a puddle on your workbench. It just takes practice to get it. From what i have been told it also looks better than TIG welding for some of the lesser quality metals, but if you need strength have it TIG welded. Let us know how you do.

I agree - and you're right, it is solder. I've found it mildly useful but not enough so to bother with. I've found it to be a PITA to use well - the proper cleaning of the joint is critical for a good mechanical bond and cleaned aluminum IMMEDIATELY starts getting ucky with a protective film of aluminum oxide, so don't get distracted.

JB Weld is great stuff and if you're impatient like me a 165 - 200 deg-F toaster oven is miraculous in accelerating the cure time to just a few minutes. (immersing a part in a ziplok in boiling water works, too, so this tip works OK in the field as well) For common off-the-shelf 2 part epoxies, JB Weld is superior to anything else I have used.

There are some other concoctions that are useful, like Brownell's Accru glass line and some unusual one part metal-filled offerings aimed at automotive repairs (high temp stuff) that I've found actually work as-advertised, but JB Weld is very widely available.

Epoxy putty is also very handy for that sort of thing - it's like playing with plasticene modeling clay and it takes a cure fairly quickly. It tools very well but is not as bomb proof as JB Weld. However, it's cheap and really easy to use. And while I have that thought in my mind... I've carried a "scrap" of epoxy putty in my repair kit for many years and it has really saved the day a few times. Just cut off a piece and wrap it up (I just used cling wrap most of the time, although I get fancy every so often and seal a bit up in a mylar bag.) Not as problematic to carry as tubes of resin and hardener.

Alcohol cleans off partially cured epoxy from your fingers very readily after molding the putty. Ethyl (denatured) works best IME, but even common rubbing alcohol works. You can also use alcohol to clean-up epoxy "overruns" from your parts before it is fully cured, but don't hose it on - dampen a cotton swab or corner of a rag with alcohol and scrub with it.

Pete, looking forward to hearing how your soldering project turns out! Post pictures if you can, please.

Regards,

Tom

Never thought of using boiling water to accelerate the cure of JB, will have to try that the next time. Thanks. Usually keep JBquik in the truck for those fast repairs, in the heat down here JBquik sets up in a couple of minutes so you have to work really fast.

For epoxy putty have you ever tried PC 7? It seems to be about the same quality as JB but you can put it on the bottom of something without it dripping off and it is moldable and it keeps it's shape.

YEARS AGO, I used to keep a pair of ear plugs on my keychain in an old Mag Lite Solitaire that had lost it's bulb (I was in a very loud Punk/Hardcore band at the time). I never thought much of it...

-John

Hope no-ones covered this (one of those threads that gets so long you can't be bothered reading all of it!). Take two used shotgun cases. Heat the brass end on one to release. Cut crimped end off other, fill with items then seal with the brass end from the first case. Simple and easy, but not one where you are going to constantly open and close it.

Why not just cut a disk of aluminium the same dimentions as the lens from the maglite and just put it in its place.

There's nothing to say that you can't if you're willing to accept the 3/8 inch increase in the diameter of your capsule.

Ed