Project Africa: Easiest Way To Make Durable 4-Foot Long Flashlight

[fyrstormer]

Honestly, I think a separate flashlight would be better. You don't want to be stuck in a situation where you have a choice between seeing what's in front of you or swinging your stick at it, but unable to to both at the same time. Also, there's no reason to risk damaging your flashlight by putting it in a position to be smacked against things.

If you want the option to attach your flashlight to your walking/fighting stick, you can easily do that by just making a hole in one end of the stick for the flashlight to fit into, and maybe add a few 1/4" bolts sticking out of the sides of the stick so the flashlight can attach in various non-combat-ready positions via 1/4" camera mounts.

 

[Lobstradomus]

Perhaps you could thread the top of whatever bar/battery holder you choose to the same thread pitch/diameter of a Maglite tail cap then just thread on any appropriately modified *D or *C Mag host. You could use a single emitter and retain some of the stock focusing and candle use function while having more throw than a P60 and more room for heatsinking and whatever driver suits your needs.

 

[Friday]

NOTES:

99.9% of the time, the light bar will be used for purposes OTHER than slamming it into something. In fact, I can't imagine a time I would need it like a baseball bat--and if I did, then I'll probably be more worried over how to get a new arm or leg afterwards, not a new light bar. Its shockproof-ness is more about surviving an energetic walk, pushing aside brush, and illumination. Also, using the high-power flash bursts would be rare. Most often, it'd be used as simply lighting up the area as I walk. Other things, too, or else I wouldn't want it to be so darn heavy (so, it has to be heavy)

"Gandalf's Staff" = LOL. I was thinking the same thing. And, yes, on occasion, it'll be used in that exact fashion: light as a defensive weapon. BTW, if anyone's actually carried around a 4'-long 10lb bar, it's more than enough of a "weapon" simply as-is.

COULD THIS DESIGN WORK? It adds up to 9-10lbs. Perfect!

4' of 1" Steel Water Pipe: Interior Diameter 26mm (total weight 6.72lbs)
-- http://www.engineeringtoolbox.com/ansi-steel-pipes-d_305.html)

12 x ER261020 CC Size Batteries: 4" long x 26mm diameter (total weight 2.5lbs)
-- http://www.alibaba.com/product-gs/502090039/SELL_ER261020_BATTERY_3_6_volts.html

Thread the "bottom" of the water pipe to fit a maglite tailpiece. Thread the top of the pipe to fit a C-battery maglite (or similar) host. Put an aluminum cage around it, or comparable. Maybe there are "rugged" hosts out there that I don't know about...

From my reading, these batteries are temperature safe ( -40C / +85C ). They can be bought in bulk for about $5-$10 from China. They'll run for a long time at low-discharge--but with so many of them, they'll still be able to kick out a good burst, if needed. The alternative would be 24 x C batteries.

Can you all give this design the once-over? If it's decent, help me take the next step: what host/light would do the trick the best. How about heat-sinking....etc etc

 

[jabe1]

Why do you want the whole thing full of batteries? that severely limits what drivers can be used, and just screams light failure. Keep it simple and use lower voltage.

Also, in Africa, I'd only want to be using AAs (Always Available). This is possible, if you simplify it.

 

[880arm]

This thread is interesting in a "what if" kind of way. I personally cannot envision a practical use for this type of light but that's just based upon my usage habits. To the OP, if you need it, then let's build it! Being from an electrical background, my first thought was rigid electrical conduit as was mentioned earlier which is, for these purposes, very similar to the water pipe.

However, after reading through the thread again, I have to ask, how do you envision this light being mounted? Will the main beam be in line with the center line of the staff (i.e. pointing straight up when the staff is vertical)? Will it be perpindicular to the staff? Or is it to be adjustable?

Also, what type of user interface do you require? Momentary actuation? Clicky? Both?

I look forward to seeing where this goes! lovecpf

 

[fiberguy]

Is steel water pipe the same as rigid metal conduit? I've used rigid metal conduit before. I built sections of it under some naval piers to run cabling. The diameter I used was much greater than what you will be using, but I can vouch for this stuff. It is beyond tough. I was shocked at what kind of abuse it would take. a 1" diameter conduit could easily, EASILY be used as a chin-up bar. I would suggest a double layer. For instance, if one piece has an outside diameter of 1.5" and another piece has an inside diameter of 1'5", then you slide the smaller one into the bigger one, you'd have a very sturdy body. In addition, it'd be less likely to bend or dent. If it did bend or dent, it'd be less likely to affect your "battery compartment"

While we're talking about batteries... Alkalines don't have to be a scary idea. They're fairly stable and very inexpensive if you know how to purchase them. Duracell Procell are the same as Duracell Coppertop (different wrapper and packaging) and they run less than half the price if you shop around. Zoro Tools (online) sells them so cheap it's silly. Zoro also ALWAYS has promo codes you can google to make your order even cheaper.

Also, your battery compartment could be separated. The top portion could have a divider so only the first X amount of cells are actually being used to power the light. All you'd need to accomplish this is some bar stock. The bottom could have a threaded cap to access your spare cells while the top could be accessed by removing the head of the light. The only issue I foresee here would be damage to the endcap or threads. If those were to get damaged you'd be screwed.

 

[AnAppleSnail]

Can you all give this design the once-over? If it's decent, help me take the next step: what host/light would do the trick the best. How about heat-sinking....etc etc

A stack of AAs is 14mm wide, and gives you (1.4v * 2 amp-hours)*2 = 5.6 watt-hours per 10cm of length. A stack of CR123s is 16mm wide and gives you 13 watt-hours per 10cm of length. Either one of these will produce a lot of light for a long time with a short 'stack length.' The trouble with a lot of batteries in a stack is that the stack will wiggle and damage cells, and the voltage becomes too high to use efficiently. 4 feet of CR123 is 107v, far too high for safe circuit design. Even 4' of common alkaline/NiMH cells will be around 60v, still uncomfortably high...and very difficult to efficiently step down to LED voltages. An efficient driver circuit can give 500 lumens for two or more hours from one 18650. An inefficient driver circuit will waste power and create extra heat.

Ergonomically speaking, you want the lightest possible weights on your extremities. My hiking pals tell me that every pound on your feet or hands is like carrying an extra twenty pounds. Your 10 pound staff might be okay for short trips, but too unwieldy for long ones. As far as marketability goes, I'd prefer an aimable light that I can attach to most poles - including my hiking stick.

Electrically speaking, I suggest two different light circuits fed from the same batteries. One to make a burst of area light, another to make a more-useful light. But my experience is that walking-staff-light combinations do neither function especially well, and usually only do one adequately.

 

[Friday]

jabe1: I agree about the availability of AA's, and I'm keeping that in mind, of course! As for wondering why I would want more batteries, could we get beyond that concern? For too many reasons to list, I need the batteries IN the bar, and I'd like as many mAh to draw from. A few AA's carrying 10,000 mAH in a flashlight-on-a-stick is not what I'm looking for.

A LightBar with 12 CC batteries carrying 180,000 mAh is more like it.

Are there engineering problems to overcome with all the voltage from 12 CC batteries? Yes! So, I've come to a forum of expert problem-solvers to do that!

Does this make sense? I'm not trying to offend, I'm trying to encourage!

John

PS: "But just stick the spares in your pocket." = The number of assumptions in that statement are too many too list. I simply need the batteries to be in the bar. And I'd love to see creative minds work the driver/host problems out, using modern technology and brains!

 

[880arm]

Is steel water pipe the same as rigid metal conduit?

They aren't exactly the same but they are similar. There are different grades of each and they have slightly different dimensions (for the same trade sizes) which can introduce some variables but one thing that is consistent is that they use different threads.

One other thing they have in common is that they are very strong, as you mentioned. I weigh 300 lbs. and a 4' piece of 1.25" Rigid conduit could easily support my weight. I couldn't do a chin-up but that's not the conduit's fault.

 

[Friday]

Ergonomically speaking, you want the lightest possible weights on your extremities.

Great ideas AnAppleSnail! But this is the opposite of the mission, here! I NEED THE WEIGHT.

I also need your expertise and creativity . . . so I'm not in a position to say, "Do it this way." I can only ask: can you solve the driver/host problems involved in having a LightBar filled with batteries?

-- Four feet of 12 x CC batteries = 42v / 150,000 mAh
-- Diameter of CC's: 26mm
-- Interior diameter of ANSI 1" water pipe: 26.7mm
-- Maglite C tailpiece screwed to bottom of pipe, with C-style host attached to the other end

My father is an engineer, and he always says the profession is primarily about problem-solving. So, how can these specific batteries be best mounted inside the LightBar, and with what host/driver?

This project has specific goals that can't be explained in a few sentences. There is a book about to be published called "The Mismeasure of Animal Intelligence" that will include the LightBar idea we're developing now. I'll post a link when it's released.

I know how difficult it is to put preconceptions aside. So, if it's impossible to help directly on this, I'm sure I'll be able to hunt-and-peck my way through the posts for ideas.

TIA!

~john

 

[Friday]

I weigh 300 lbs. and a 4' piece of 1.25" Rigid conduit could easily support my weight. I couldn't do a chin-up but that's not the conduit's fault.

I rejected the conduit because the Interior Diameter of 1.5" (trade size) was enormous. Even the smaller 1.25" Rigid conduit had an interior diameter of 1.4" . . . which is much to wide.
-- http://www.fastenal.com/web/products/detail.ex?sku=0700023

But . . . 1" Rigid Conduit = 1.3 OD, 1.06 ID.

Success! That'll fit C/CC batteries nicely!

So, does anyone have experience with the 1" rigid conduit, as far as strength goes?

 

[fyrstormer]

jabe1: I agree about the availability of AA's, and I'm keeping that in mind, of course! As for wondering why I would want more batteries, could we get beyond that concern? For too many reasons to list, I need the batteries IN the bar, and I'd like as many mAh to draw from. A few AA's carrying 10,000 mAH in a flashlight-on-a-stick is not what I'm looking for.

A LightBar with 12 CC batteries carrying 180,000 mAh is more like it.

Are there engineering problems to overcome with all the voltage from 12 CC batteries? Yes! So, I've come to a forum of expert problem-solvers to do that!

Does this make sense? I'm not trying to offend, I'm trying to encourage!

John

PS: "But just stick the spares in your pocket." = The number of assumptions in that statement are too many too list. I simply need the batteries to be in the bar. And I'd love to see creative minds work the driver/host problems out, using modern technology and brains!

An AA cell is 50mm long. A 4-foot bar full of AA batteries would hold 24 batteries, and produce 36 volts, which is 10 times the voltage necessary to drive an LED. Downconverting the voltage at a 10:1 ratio would waste a large portion of the power contained in those batteries. Furthermore, having 24 AA batteries in-series means there is 24 times the probability that a single-cell failure would make the light useless until you can dump out all the batteries, test every single one with a voltmeter, and replace the one that's gone bad -- and it WILL happen at the worst possible time, because that's how life works.

Engineering doesn't mean you can get whatever you want, it means you can get a solution with a reasonable number of tradeoffs. The light you want *can* exist, but it would be wasteful and unreliable. You asked for advice, and you're getting it, but unlike your stated intention, you don't seem to want any advice because you've already decided what design you're willing to consider.

Having to swap batteries every couple days is a much better solution than trying to use all the batteries you have at once. You can always use most of the tube for storing batteries; they don't have to all be providing power at once.

 

[Friday]

You asked for advice, and you're getting it, but unlike your stated intention, you don't seem to want any advice because you've already decided what design you're willing to consider.

Gosh, that's not what I was doing at all. I'm sitting here with pages and pages of notes on my desk from all the posts, 40+ websites bookmarked, and original designs that I've modified like 10 different ways from the suggestions. Plus, I've thanked people when they given a great idea. Plus, I've offered royalty rewards if these ever gets into production.

I feel like it's a good idea to interact with people -- and possibly make some mistakes myself along the way -- before coming to an educated decision. Am I wrong in this approach? PM me and tell me how I could be better for you, because my goal is to tease out genius and innovation . . . not to encourage doors being closed on my fingers. I already get those bitten enough.

 

[fiberguy]

I'd say it's as strong as you're gonna get in my experience. I'd go galvanized; you don't wanna have to worry about corrosion. This stuff is strong as balls (to put it in technical terms). Again, it wasn't as small, but the stuff we installed was over 600 feet in length suspended underneath a pier. Not a wooden fishing pier, a concrete park-an-aircraft-carrier-here pier. It was hung by a trapeze system and during high tide was brutally beaten by waves. It's been in place for 7 years and has yet to fail. We installed it to protect fiber optic cables (the umbilical) used to connect ships when they were at shore. Once complete, we pulled in too many cables to fit. There were several 90 degree bends. We ended up using a Vortex Max in 4WD to pull in some 400 pair. The conduit never even flinched.

I've played with smaller rigid conduit pipes. I'd gladly trust it to support the weight and force. You could reinforce the end by welding in a 2 or 4 inch chunk of bar stock.

 

[Launch Mini]

Honestly, I think a separate flashlight would be better. You don't want to be stuck in a situation where you have a choice between seeing what's in front of you or swinging your stick at it, but unable to to both at the same time. Also, there's no reason to risk damaging your flashlight by putting it in a position to be smacked against things.

x2
Also, I think it would be akward holding the 8lb rod in a position to actually use the flashlight, AND, if you do drop it on the business end, there will be some serious force of the 8lbs hammering down on your flashlight. That would be one tough mother of a light to withstand that.

I would opt for a separate light, and maybe a magnetic mount. That way you could attach it there, and remove when you start swinging and if you drop it, the magnet would release and hopefully save the light.

 

[Friday]

I'd say it's as strong as you're gonna get in my experience.

Tx! I'll check it out. Never would have guessed.

Now for the tougher fantasy-in-reality stuff, for all those interested.

Standard assumptions about efficiency and effectively don't always apply here:

1. Efficiency is not a concern regarding the 5-second "Max-Burst" capabilities of the LightBar. Nor is material safety. What matters is this: make it as bright as possible for 5 seconds. 360-degrees if possible. If it blows some circuits or ruins batteries, so be it. If it's horribly inefficient, that's irrelevant--I don't care if that means incandescent or plasma. Even if it turns into a roman candle, that's fine: it'll add to the illumination. NOTE: I'm mostly joking, but REM: this thing isn't a flashlight, and there aren't any people when/where it goes.

2. Once the bar I carry is upgraded to a LightBar, I won't be carelessly using it like the hunk-of-steel it now is. It'll be a bar with a light and batteries, and that means to be decent to it. So, figure it being used to push aside brush, do chin-ups, and be carried around while walking. If I'm attacked, which would be like a cop being shot, then it may take a licking and be ruined. Time to buy another, not to criticize CPF'ers for not protecting my LED's from lions.

3. It's not the only light source I have. And I can see up close, except for the very darkest of nights. Just FYI's about the variables involve while using it.

I'm trying to playfully scientific in my tone/approach here. And I truly appreciate any and all contributors, to the tune of 20%. You never know: what I'll be doing with the LightBar might become popular.

~john

 

[AnAppleSnail]

Gosh, that's not what I was doing at all. I'm sitting here with pages and pages of notes on my desk from all the posts, 40+ websites bookmarked, and original designs that I've modified like 10 different ways from the suggestions. Plus, I've thanked people when they given a great idea. Plus, I've offered royalty rewards if these ever gets into production.

I feel like it's a good idea to interact with people -- and possibly make some mistakes myself along the way -- before coming to an educated decision. Am I wrong in this approach? PM me and tell me how I could be better for you, because my goal is to tease out genius and innovation . . . not to encourage doors being closed on my fingers. I already get those bitten enough.

With the stated goals of durability and efficiency, I'm unclear as to why our concerns about circuit design (Designing safe and durable circuits for over 60VDC is a whole other ballpark than 10VDC) and battery condition seem to go so unheard. You say "Thank you for the idea, but I think it should happen that way anyhow."

All battery motion in the tube is bad. It risks intermittent contact. It risks damaging the bottom battery as all of its friends pile atop it. It risks damage to the battery wrapper. Not everyone knows that the side of most cylindrical batteries is common to the negative side. If battery #1 scrapes and makes electrical contact with the wall of any flashlight, all the cells "behind" it (talking to battery #1s negative contact) will short out. This will probably release an exciting, dangerous, and light-disabling amount of power...because even if the light survives, it now has dead-short cells in series with its power supply. This prevents light function.

Most flashlights have up to 3 cells, and the ones that do have quite stiff springs to stabilize the cells. Few flashlights that are designed for high-impact purposes use more than two cells (Many weaponlights use 1 cell to help with this problem). You've now written hundreds of words giving insufficient information as to why you feel that your high-voltage, high-risk-of-battery-failure design is best. Will you fill us in on these 'little details' you continue to withhold? We give the best suggestions we can. Enable us!

 

[gravelmonkey]

Have you tried just duct-taping a flashlight to your current 'pry-bar'? Maybe as "prototype-1" Just to get a feel of where the lumens are going, type/location of switch etc? IF you ever took a swing at something with the heavy (non-lit end) al-la baseball bat style, the light would be illuminating you!

Seeing as this is a bit of a brain-storming thread, I'll just throw these other ideas out there:

-Custom built-in Ni-mh pack from C cells with a charging port- I'm not great with the electronics side of things, but I'm guessing it would be easy enough to wire them in an arrangement to give ~4.6V and more mAh than you can shake a stick at... YES its not exactly field serviceable, but that's the trade-off, no biggie if you're carrying a back-up light (would be a problem if you don't have power to charge it- Solar? I'm going to assume you're off-grid, there is no other logical reason to need SUCH long runtimes).
- A lantern-stick would be cool- a set of 3? LED's countersunk into the tube at 120 degrees to one another- basically a CREE version of Gandalf's staff..
- Would a camera flash type thing be sufficient for your short and bright requirement?
- Would an angle light be more useful to walk with? (Like those military ones...just 4' long! :devil
- Why does the whole thing need to be heavy? Would a 4-5lb 'head' and long handle be lighter to carry and still have a good 'swing factor'?

Anyway, just thinking out loud!! I'm fascinated to see what you come up with!



GM

 

[Tegan's Dad]

In all fairness it was mentioned that most of the length of the light could be used for storage rather than active cells for use in the light. The trick then becomes how do you partition the light to have the "active" cells and "inactive" cells at the same time.

I think another very useful idea would be to use some sort of padding/shock absorbing material on the inside of the tube to help "protect" the batteries. Some random suggestions would be the insulating foam used on plumbing pipes, radiator hose, or even some o-rings wrapped around each battery. It wouldn't hurt to have some sort of cap on each "storage" battery either, and still use a spring of some sort for the storage compartment to maintain some tension. The spring could be metal, foam, rubber...

I've been an engineer for 10 years now, and it is definitely about trade-offs when problem solving. The most famous of trade-offs is to say you want low cost, extremely durable, and fast time to market. You can have 2 of these but not 3.

It is a very interesting concept to throw around, hopefully we get to see what you come up with!

 

[Ezeriel]

this is just getting too confusing.... Is this a lantern, or a flashlight?
if it's a flashlight, is the light coming out the top (up) or to the side?
This burst you want... how many lumens are you talking about?


I think the first thing that needs to happen here is that Friday needs to pick out a flashlight.

perhaps a fenix LD22, LD41 TK41.... hell.. you could just buy a TK60 or TK70, and we can call it a day, for all I know