# Headlamp on Helmet - Project in Progress



## Bolster (May 2, 2011)

I wear this Petzl helmet in attics and crawlspaces; saves my noggin from nails, concrete, dirt, and head bumps. Have always just slung a headlamp around it, but have been dreaming of a more secure mounting. So finally started. Was challenging to drill two holes in the helmet exactly 1" apart, and centered. (Also, this invalidates the warranty.) Glad that's done. No turning back now. 







Now for cutting the mount. This was also tricky. Had to estimate the diameter of the helmet on the front part (effective diameter changes depending where on the helmet you are). Then also had to machine in a diagonal at the same time, since the helmet curves back. Here I've jury-rigged a rotary table with an extension and an auxiliary vise. The block of aluminum has been tilted to exactly 14 degrees, and the radius of the cut is 4". Slow going as the setup is not very rigid. 






And here's the little b*st*rd after slotting and tapping. The slot is to lighten it a bit. It's .8 oz total. So much work for such a small piece. The outrigger holes are 1.4" apart and are for mounting a future light. Haven't decided which, or how many. 






After stone-washing and a coat of clear lacquer, now mounted to the helmet. Nice tight fit, very secure. Reasonably low profile at 1/2 inch protrusion. Have run screws into the light-mount holes temporarily. The inner two holes are for the screws that mount the bracket from the inside of the helmet. Those screw heads are low profile, with washers to spread the load, and are underneath padding. 






Now that I've got permanently mounted threaded holes, I need to choose a light. Am considering the H60w's that are in the mail. Don't know whether I'll mount one or two. I kinda like the idea of two, for redundancy sake. (Note that the headlamp strap mounts are back in place and still functional if I want to add a light that way, too.) What do you think, one light or two? Open to suggestions. 

To be continued...


----------



## Microa (May 3, 2011)

Neat and solid, well done. Will you consider one XML with 3 levels driver and remote Li-ion battery pack at the rear?


----------



## bnemmie (May 3, 2011)

Nice. I know cavers and rock climbers use something similar to that with a universal slot system certain lights designed for that purpose have. This seems even more secure then that. Well done.


----------



## Bolster (May 3, 2011)

Microa said:


> Neat and solid, well done. Will you consider one XML with 3 levels driver and remote Li-ion battery pack at the rear?



That sounds great, but one issue I have in crawlspace work, is I'm often resting my head in the dirt while looking up at the floorboards. Which means the sides and back need to be clear. I only have the front of the helmet to work with; even mounting to the top of the helmet would snag on studs as I crawl around. Think of crawlspace work like constant tight-quarters caving, but without the possibility of getting lost. 

But if I were actually caving? Heck yeah, I'd make a second mount for the back of the helmet for the battery pack.


----------



## goose2283 (May 3, 2011)

Wow... Beautiful work!


----------



## Bolster (May 3, 2011)

So I need some help thinking this through. The clamp for the actual light (assuming an H60 for the time being) can be done two ways. First, you can make a cylindrical hole for the light to nestle in. You need to get that hole within a couple thousandths, which is doable. When you apply the clamp pressure, it is very evenly applied over the broadest possible area. This clamp I made for an H50 to a tripod is that sort, with very close tolerances and even clamping pressure over the widest possible area (for a given size): 






But there is a downside to this method: it primarily fits one diameter well, no diameters larger, and with a two-point contact for diameters slightly smaller (not ideal). For example, this clamp for the H50 (.645) will not fit the H501 since the H501 is a slightly larger diameter (.650). Yep, 5 thousandths of an inch means no fit, since I made it to a tight tolerance. (The tolerance is so tight that just the lower half of the clamp alone will hold the light.) If I'd made it for the larger H501, I could clamp the smaller H50 in it, but clamping pressure would be primarily at two points. 

So the problem with a hole that precisely fits a particular light is: pretty much that light only can be used, and lights of somewhat less diameter can also be fit if you're willing to clamp it at two points. 

An alternate system is to borrow a concept from the V-block, used in machining to hold round parts. 






A V-block contacts a cylinder on two points (if just one is being used), and if you made a clamp consisting of two v-blocks, one top and one bottom, you'd essentially have contact on 4 points, around the light every 90 degrees. The disadvantage here is that you'd have 4 "hot spots" rather than one even and widely distributed clamping pressure around a cylinder. Also this would be somewhat bulkier, to accommodate various sizes. But the advantage is that you could fit different sized lights (within the range of capacity of the V-blocks). I could probably switch out a variety of lights within the AA to the 18650 range if I went with this system. Ie, I'd not have to throw away my clamp when a new light comes along. 

What do you think? Can you see any major trouble with the V-block system, as long as I'm not using crushing pressure to tighten down the lights? (Which you would not want anyway; they need to rotate or slip a little along the axis for vertical beam adjustment).

I'm also contemplating some sort of "padding," either a rubbery substance adhered to the clamp block (the hard way), or possibly a couple of winds of electrical tape or a couple of o-rings around the body of the light itself (the easy way).


----------



## Microa (May 3, 2011)

Do you think to put flexible plastic sheets between the light and the clamp of method 1 is acceptable although the adjustable range is not big. Many cycling lights mounting to the handle bar use this method.


----------



## tedh (May 3, 2011)

Sure, V-blocks should work. Two possible problems I can see - 

1. As long as you don't apply crushing pressure, you're fine. But I worry about the person you loan the headlamp to, who just happily cranks down with the Allen wrench and dents (or worse) the light. As long as you know you're never going to loan it out, I think it's fine. 

2. I would think the metal-to-metal contact requires a fair amount of pressure to keep the light from rotating. I'm not sure how much of a pressure "gap" there is between "enough to keep the light from moving" and "uh oh, I dented it". Seems to me you'd be wise to put a thin sheet of something in there to spread the pressure a little bit, and also to give you some friction so you don't have to whale away on the screws to keep it from moving around. 

As another thought, what could you do to attach a hose clamp (or two) to the aluminum block? The hose clamp would spread the force around the round body of the lamp. It would look terrible, of course. Perhaps there is a more elegant hose clamp like mechanism?

Ted


----------



## Bolster (May 3, 2011)

tedh said:


> I would think the metal-to-metal contact requires a fair amount of pressure to keep the light from rotating. I'm not sure how much of a pressure "gap" there is between "enough to keep the light from moving" and "uh oh, I dented it". Seems to me you'd be wise to put a thin sheet of something in there to spread the pressure a little bit, and also to give you some friction so you don't have to whale away on the screws to keep it from moving around.


 
Thanks for thinking this through. No loaning so I'm good there. Made of aluminum so a v-block would be relatively soft. What do you think of encircling the light with a couple of o-rings before v-clamping? Hose clamp is very practical but I can't do it for esthetic reasons!


----------



## Microa (May 3, 2011)

> I'm also contemplating some sort of "padding," either a rubbery substance adhered to the clamp block (the hard way), or possibly a couple of winds of electrical tape or a couple of o-rings around the body of the light itself (the easy way).


Sorry, I omitted this statement.


> That sounds great, but one issue I have in crawlspace work, is I'm often resting my head in the dirt while looking up at the floorboards. Which means the sides and back need to be clear. I only have the front of the helmet to work with; even mounting to the top of the helmet would snag on studs as I crawl around. Think of crawlspace work like constant tight-quarters caving, but without the possibility of getting lost.


The failure of the battery sometimes without any alert. Two lights are better than one.


----------



## Bolster (May 4, 2011)

I tried the v-block solution on paper .... ugh ... it's a no-go. Takes up too much real-estate, looks clunky, would be heavy. 

Back to the drawing board. I'm now experimenting with "shoe" designs, where you have a very simple mounting system with custom "shoes" for a particular light diameter. So far, I can get this design much more compact, lightweight, and it also appears to reduce the amount of machining necessary.


----------



## Glock27 (May 4, 2011)

I would really like an H50/H501 mount for a hard hat. 
Could you machine them out of derlin?
O-rings sound great to keep from marring or squishing the tube. 

G27


----------



## Bolster (May 4, 2011)

So the latest design I call the "shoe rack" design. A vertical rack (actually two, a T-rack to the fore and a straight one aft), to which will be affixed "shoes" (or cradles) to hold the lights. Here's to scale for two H501s, because I don't have dimensions for the H60s yet. The lights would mount *behind* the main (front) vertical rack, keeping them close to the helmet and not protruding overly much. The shoes would be semi circular cradles to the precise size of a particular light's diameter, made of some sort of plastic material, but don't know what sort yet. This would allow for a "delicate but firm" grip on the lights. Picking the plastic will be important, because I think that epoxying the shoes in place is the best solution, and the plastic would need to be "epoxyable," none of the slick or oily plastics could be used. On the backside of the two lights (and four shoes) would be the second (smaller) rack, another vertical, held to the front rack by the two screws between the lights. Basically a flashlight sandwich, if you will. If the shoes are slightly inset into the racks, then there'd be very limited possibility that an epoxy failure would drop the lights, as the shoes would be locked into place. 

This design has the advantage of compactness, and not needing a lot of metal around the base of the bottom light (which would hold the lights further away from the helmet). Also has the advantage that the front vertical "T-rack" will help protect the lights somewhat against unintended collisions. Lights are tucked in near the helmet (although the high one would be hanging out there farther). Have considered a back-bent rack but dismissed it due to machining complexity. Will likely add a "bumper" to the back rack, so the bumper hits the helmet before the racks have to bend backward. Rigidity of this setup is unknown, but planning the front and back racks out of .250 aluminum, that's pretty sturdy. Loose screws mid-rack would be catastrophic, would drop both lights. Am considering a 3-screw rack-attach solution (above, between, & below the lights) but that would make for a larger, bulkier mount. 

To change diameters of cradles, you'd simply machine away the plastic shoes and the epoxy holding them, and epoxy in new shoes. So, an update every year or two would not be such a huge job. And some leeway of flashlight diameters would be permitted. Also, making a shorter T-rack would allow a lower profile single-light mount. You could change from a 2 to 1 light solution by replacing the rack. 

@Glock - have not worked with Delrin. I'm not an experienced machinist (or designer, which is why I'm asking for criticism of my plans before I start machining). I don't know why you couldn't machine out of Delrin; threaded attachments would be my first question.


----------



## kevinm (May 4, 2011)

Delrin threads pretty well, so that wouldn't be a problem.

The design above looks good. I'd move it down a bit, simply because I think your upper light is going to catch stuff, move the lights closer together, and move the bottom one closer to the horizontal piece. 

Rather than o-rings, have you considered automotive hose? It's tough, would give you a clean look, would grip well with a little pressure, and wouldn't move as much as o-rings.

Here's a totally different idea: Why not use the block you have and mount one above and one below? Use one half of the clamp in post 6 for the top, one half for the bottom. With the bit of hose, it would be secure. You could even make a wider one that would cover the body except for the head and tailcap, giving you maximum hold and allowing you to change batteries without removing them from the mount.

Kevin


----------



## Glock27 (May 4, 2011)

I don't see a need for a double mount. Your nice slim minimal cool looking mount is turning into a monster. ;-) IMHO.

G27


----------



## CarpentryHero (May 4, 2011)

Zebralight has some XML angle lights coming out, you may now need a double light. 
Though if I were able, I'd build both set ups and have it swappable :naughty: 
It gets dark early in the spring and fall here


----------



## Bolster (May 4, 2011)

@ Glock: Appreciate the honest evaluation, and yes, at least a minimum of esthetics are important to me. Yeah, I'm concerned about monsterization, too. It looks bigger on paper, than in my head. LOL. And the mockup is with smaller H501s, not the larger H60s! So it would get larger yet. To your point, one H60w should provide plenty of light and runtime, 91 lumen for 4 hours or 37 for 10 hours. I have been considering both a single and double mount, but maybe I tackle the single mount first. A single mount would require a different setup, much more like the tripod clamp I did above. Downside would be, no redundancy. Just last night I had a Zebralight wink out with no warning (they're supposed to flash a few times at low battery!). 

@ Kevin: Good idea re hose for aV block design, and that's two concerns logged about the height of the top light now. Moving closer together gets tricky, you can't see the slope of the helmet from the side but there's not a lot of room to slide further down. Also you need room for tapped holes, etc. Had considered the above/below-the-mount-block design, and laid it aside as it drops the light below the brim. Also considered a top/back and lower/forward design, but didn't pursue it as it puts weight forward, and allows the forward light to cast a shadow from the rear light.

Delrin threads, sure, but do the threads hold or strip? Esp. for the small threads required for small attachments? Machinists have concerns about aluminum threads holding, at least they're metal. I always make sure that my threaded aluminum attachments are plenty thick to allow at least a half dozen threads.


----------



## tedh (May 4, 2011)

I'm still thinking the hose-clamp method has some merits. it's very low profile, for example. This system http://www.topeak.com/products/Xtras/BarXtender uses a stainless steel strap to attach to a bike handlebar. I wonder if a similar approach would work. You'd need a way to tension the strap around the light, and against some sort of block (probably padded). But in return you get a very low profile attachment method. 

Might be worth a trip to the local bike store to see how they attach stuff to bicycles? Lights, handlebar bags, and so on. 

Ted


----------



## Bolster (May 4, 2011)

The H60w's arrived today. Forget about putting two of them on a helmet! They're huge (comparatively...to AAs). Definitely back to a single H60, if an H60 at all.


----------



## ahorton (May 5, 2011)

I know you already have plans for this but one thing keeps niggling at me every time I look at this thread.

Why not grab a bigger bit of aluminium and build the whole light into it? You'd lose the angle adjustment, but you could probably get it pretty close to what you want and you're using pure flood anyway.

I'm imagining a block of aluminium approx 85x40x30.
20mm bore down the length to accept an 18650.
Threaded on the end to accept a screw-in plug.
Give one face a beautiful curve to fit against the helmet (like what you've already done). Angle it so that the opposite (front) face is perpendicular to the angle you want the beam.
Give the opposite (front) face a 20mm diameter hole (10mm deep) to accept an XP-G on MCPCB.
Add a step to allow gluing a 25mm diameter, 3mm thick polycarbonate lens.
Add another hole for a switch where ever you like it.
A 17mm driver should fit in the hole with the 18650.
Smooth off all the corners

You'd end up with something that looks like a brick that got pushed into the helmet.
Very, very solid.
Nothing to snag on.

Very few places for water to get it (silicone up the lens, add an o-ring to the 18650 plug and if you really want, you can use a magnetic switch)

This was what I thought of as soon as I saw this thread.



You could make it more compact by putting the LED and switch above or below the 18650. Make the cavities for the LED and switch overlap with the 18650's so that you can pass a wire between.


----------



## Bolster (May 5, 2011)

Ahorton, sold! Sounds like a wonderful light--the IDEAL light. Far beyond my abilities...I don't even own a lathe. No single-point threading, tap and die my only option. The "modular" approach is indeed a compromise. Upsides are that if I ruin a part I don't ruin the whole project; and even more important, if I change my mind I just machine a different part. But whatever I make will not be "rock solid." Heck I can't even get the pieces clamped into my mill by the "rock solid" standard. You should have seen the chatter cutting that compound curve. 

I am having second thoughts about mounting the 18650, much larger than I was expecting, and I'm a novice at LiIon, so I'm once again strongly considering mounting two of the little 1xAAs. I dunno, need to think on this awhile. But the input is much appreciated.


----------



## Bolster (May 29, 2011)

After laying this aside for several weeks I picked it up again. Thought about it several different ways and I keep coming back to the "rack" design. Playing with the idea of two lights for redundancy. (Can make more holders later for single lights.) What I didn't like about my first design was how far the rack stood up and away from the helmet, but could not think of a simple fix for it. So I designed this; it may be beyond my ability as a machinist, it's not really a design for a novice to make. The angles require tooling that I don't own yet (an angle vise). Still thinking it over. 

The angle complicates everything, but it does keep the lights in close to the helmet, and foreshortening lowers the height somewhat. I *do* like the simple and elegant self-adjusting solution for clamping two lights. No bulky encircling rings, just a straightforward clamping mechanism. Posting here to get criticism of a design issue I may have missed. 

I would likely pad the back part of the clamp with rubber, so the rack can't be bent back. The helmet would stop rearward movement.


----------



## Gregozedobe (May 29, 2011)

Lots of good ideas floating around here. My .02 worth:

KISS

Only go for one light on the helmet (H501 would be my prference), keep the spare (complete light and O rings in your pocket) where it will be out of harms way, no chance of getting misplaced if you really crack the front of the helmet on anything etc etc.

Look at the way cyclists use large (& thick) O rings to mount stuff to bikes (eg very small lights on to seat tubes and handlebars)

File/machine a piece of delrin/construction plastic with the back hollowed out to match the helmet, and a shallow horizontal U on the front for the light. Add in 4 small round head screws as lugs for the O rings on the top and bottom (leave the heads protruding slightly so the O rings hold on the shaft below the head), mount the block to the helmet as per the piece of aluminium you have shown in pictures (with screws all the way through). 

Mount the light so that the tailcap isn't touching anything and you will be able to change batteries without removing the light.

This could be done with just a couple of files/rasps and a drill, doesn't need to be fancy at all, keep it small and low profile so the light is close to the helmet (maybe 1/3 the thickness of the original Alu block ?). 

No charge for the ideas, but please post a photo of the prototypes and finished "objet d'art"


----------



## Bolster (May 29, 2011)

Thanks. Interesting, I don't follow all of it without a drawing (can you post a link to the large/thick O ring mount example?), but: 

- Are you saying the O-ring retains the light? O-rings crack and break! Doesn't take too long, either, in my experience.
- Doesn't address the two-light ideal (when one blinks out you still have light to get back). Had Eneloops go flat on me before, not fun. Suddenly very dark. Yes, the cells can be changed with above design but I'd prefer not to have to worry about that while down below. 
- Flashlight in the pocket isn't an option for my crawlspace spelunking. Pockets can't be used at all. You can put a spare cell or light in the push box, but keeping the spare on the helmet is ideal. Your upper face and forehead are about the only surfaces that don't get thrashed while crawling around. What I'm looking at here is a "build your own" 2xAA Zebralight, basically. 
- I also prefer more light/longer runtime than a 501 alone. Plan is to run them at the midlevel 15 lumen, giving me 30 lumen total for 19 hours. That'll do me. I am hoping that the new H502s will fit the clamp. I would not complain if I could get 50-60 lumen. 19 hours is excessive, but I do need 4, or better yet, 8, with no cell changeout, and redundancy preferred.

I do agree to the KISS, and I'm trying to KI as S as this S designer can, while still meeting design goals. I do like the idea of a strap...I wouldn't go rubber, but maybe nylon...but can't figure a simpler way to use a strap yet. 

BTW, my two-light design doesn't preclude my making a 1-light design later. I was going to make the single clamp after the double-clamp was up and running. The whole purpose of the "aluminum boss" design was to allow easy changeout of different clamp mechanisms.

Or, I may bin this design and go back to a clamp for a single H60, if I can find a decent charger and cell. But that arrangement is not so good for the secondary purpose, emergency use. (I'm a CERT member.) In emergencies I'd prefer to have AAs, not mess with LiIon recharging.


----------



## ZebraLight (May 30, 2011)

Bolster said:


> I am hoping that the new H502s will fit the clamp.


 
The diameters of that section are 18.2mm (H502) and 16.5mm (H501).


----------



## Bolster (May 30, 2011)

Thank you, Lillian, that's a big help. That tells me to make the clamp for the larger diameter, and the smaller diameter will mostly fit (or will fit with a wrap or two of electrical tape). Other way around, and it would be a no-go.


----------



## goose2283 (May 30, 2011)

I like the two-light clamp, but it seems needlessly complex. Why not make it a symmetrical piece with only right angles? You could place your helmet mounting block right behind the middle of the yoke.
Forgive my wholesale butchery of your CAD drawing...


----------



## Bolster (May 30, 2011)

Hmm, let me see what I can do along those lines. Thanks for the feedback. It might be worth hanging the lights further out to the front, in exchange for simplicity of machining.

The lug must stay where it is; it's in one of the few areas where you can actually access a screw on the inside of the helmet. (Else is glued in foam. I'm not up for trying to remove and reglue foam, or for drilling holes through the foam.) Also the lug needs some depth so you can have sufficient threads into aluminum. But you are correct that the angled rack is a difficult bit of machining.






The new issue is the projection distance, 1.75" from the helmet. 

Someone will certainly say, "cut down the projection of the boss." But then I give up my preferred easy location for a single light placement, up and behind the boss. Also, the boss depth is what it is, to give sufficient purchase for the threads. And, cutting down the boss would net you maybe .25 an inch, best case.

EDIT: Sadly Goose's design would not work; the upper light would shine into the body of the lower.


----------



## Bolster (May 31, 2011)

The RHINO is born...


----------



## goose2283 (May 31, 2011)

Great work! You obviously have a good relationship with your machine tools. I'm looking forward to seeing how this turns out.


----------



## vtunderground (Jun 1, 2011)

That's some fine machining!

Have you ever considered building you own headlamp? That way you could make it as floody as you'd like


----------



## B0wz3r (Jun 2, 2011)

Bolster, that's some nice work there... But just to throw a monkey wrench into things, I did something similar with my H51w, but a completely different (and admittedly a hack job) method, but it works for me...

I bike a lot, and wanted something on my helmet for use off the bike, so I just took one of the extra silicon rubber holders the ZL's come with, trimmed down the base, and used a velcro strap through the center vent hole in my bike helmet to mount the light. It nestles neatly under the visor of my helmet, and is easy to access. I don't have any pics of it to share right now, but I can do some later and post links.


----------



## asval (Jun 2, 2011)

Nice project and thanks for sharing it :twothumbs

I'm thinking of trying something similar only a little more easier since I lack tools and your awesome machining skills.

I'm thinking of buying this helmet which isn't really rated for cycling use, but I figure it should be ok unless I'm in some place that requires strict helmet ratings to legally drive a bike. Then depending on which I light I choose for it, I might either buy some expensive adapter for it or figure out a way to rig it myself.


----------



## Bolster (Jun 3, 2011)

Thanks for the kudos, folks, and for overlooking my project's "monsterishness." Bowzer's idea is great...just attach the spare "double silicone ring" directly to the helmet for an ultra-low-profile mount. Easy and fast. Only downside is it doesn't allow you to play around with your mill (smirk). 

I haven't had the spare time to finish the mount yet, maybe next weekend. I found it very challenging. Hardest project I've tried yet (I'm a novice wanna-be machinist) and what made it so difficult was (1) getting the radius transition to the "rack" (square would have been easy...radius needed a longer bit I don't own) and (2) getting those detents right. Whew! I was using a new-to-me tool, a boring bar. It worked well but I won't know if I've got those detents bored deep enough until I get the backplate made. 

Getting the detents the correct radius was a stitch, too. Diameter of the light + thickness of some electrical tape + a bit to spare...how much slop do you allow? I gave myself +.002...is that enough? Don't know!! Last thing you want is to be undersize on your detent; then the light won't fit at all. 

There are a few other embarrassments...somehow I managed to uncenter the holder from the boss by 5 thou. I must have measured with a chip under the calipers, which threw it off. Not a big deal but it bugs me. And, I have a real problem designing things to the correct slenderness. At the last minute I always thicken things up (from .20 to .25 in this case), fearing fragility, and then things come out "overdone" as you see here. My mount is going to weigh as much as a third light I fear. 

Whereas Bowser's approach keeps weight to a minimum, too.


----------



## fixitman (Jun 3, 2011)

Its an interesting project, and nicely done, but I think its way overdone for mounting a zebralight to a helmet. All you really need is a short piece of aluminum or plastic pipe, cut in half lenthwise, and 2 O-rings. glue or epoxy the half pipe to the helmet with the open side out and horizontal. Use the O-rings to hold the zebralight in place. Rock solid. I use a similar setup at work for mounting my zebralight to a bump cap..
On mine, I cut grooves in the pipe where the O-rings go, to keep them from sliding around.
Wish I had pictures, but I dont, sorry.


----------



## ryguy24000 (Jun 3, 2011)

Bolster, how much are you going to charge for one of those bad boys?


----------



## Bolster (Jun 3, 2011)

Agree it's overkill. There are much easier ways to attach a Zebralight to a helmet! Maybe not as fun, but easier. 

Remember one goal I have for this is a "modular system" where I can change out to a different headlamp(s) with just two screws AND I intend to put a similar boss on my CERT helmet that can use these same light mounts. I didn't want a permanent mount for any one particular type of light.

Another goal I had was some sort of a bumper that would help protect the lights. This gangly thing looks like the skid plate of an off road vehicle...and that's by design. I wanted a big contact area to protect the lights. And as you can imagine, the setup is extremely (overkill) rigid. Failure point will be the screws going through the helmet...the helmet itself will tear. There are reasonably large washers on the backside to help prevent this, but the aluminum mount "isn't budging." As I said, I've committed the novice's error of making things too hefty. The rack itself weighs .8 oz, whereas my EDC version of a Zebralight (using the DavidT1 carry method) is 2.5 oz complete. 

If I were to sell this I'd be making pennies per hour...but one of the goals is to keep me practiced on the mill, so a bit of complexity doesn't bother me as it's a way to stretch and learn. I'm now scheming ways of adding "lightening cutouts" to reduce fractions of an ounce of weight.


----------



## Cataract (Jun 3, 2011)

Bolster said:


> The RHINO is born...


 
 Didn't know Rhinos impaled Zebras

But seriously. this is a very nice project. I would personally go with one flood and one throw, but in your case you probably don't need to see all that far.


----------



## Bolster (Jun 4, 2011)

Testing...still working out some kinks, but things are looking good...solid and stable. I went back and deepened the detents all around. The lights are firmly clamped and I have no fear they'll fall out. Does a great job of getting light on the task, with lots of options for illumination levels and direction. I really like the 30 lumen level (both lights on medium). Despite the added ounces of aluminum, the extra weight seems to spread out across the helmet when it's worn, and isn't terribly noticeable...although I've not worn it all day yet so it's early to call. Still, I'd love to shave some weight. 






It's a big relief that the detents are the right size (there's a layer of electrical tape in the detents to protect the anodizing). I've got some sharp corners that need attention, none of the lighten cuts have been made yet, and then onto a stone tumbling and clearcoat for finishing.

One drawback: I had hoped the lights would slip a little in their mounts, for on-the-fly adjustment with no need for a screwdriver. Not happening. Even the lightest tightening of the screws locks the lights firmly into place. Ideas? Only one I came up with is to replace the electrical tape with a slicker type of tape (do they make a thin, adhesive-backed teflon or UHMW tape?).

HEY, my Zebras are different colors! LOL! Never noticed that before.


----------



## tedh (Jun 4, 2011)

Nice! Looks great, is clearly doing the job. As far as adjustments the angle of the light, I think most any material will lock the lights in place when the screws are tightened. How about replacing the normal screws with thumbscrews? You could reach up, loosen the thumbscrews, and rotate the light to the new position. This would be considerably easier if the two screws are replaced with just one thumbscrew. I don't like the lack of redundancy, however. 

Ted


----------



## Bolster (Jun 4, 2011)

Tipping the scales at 1.4 oz, despite my best efforts to lighten it further. Everywhere else I looked, I thought, "I might need that for strength." So it stays the weight it is. The two ZLs w/ eneloops weigh +3.4 oz, and the boss was .8, so we're at 5.6 oz total. BUT we save using two ZL straps, 1.6 oz, so we're just .6 oz over strapping the lights on; I can live with that for the additional security. 







A footnote: Mounting the lights higher on the helmet would NOT have worked, I find. Since the lights need to shine more down than out, the higher you mount them, the more the front light would likely interfere with the beam of the hind light. While I got lucky (I hadn't modeled the beams), next time I design any kind of mount, I will definitely do that. The wider the beam, the more careful you have to be of placement.

The mount is currently being stonewashed; should be done in about 3 hours. 

Final shots:


----------



## Lynx_Arc (Jun 4, 2011)

what you may need is a plastic or nylon sleeve the lights fit in that could allow the lights to spin in place and something like spring washers under the screws also. The aluminum to aluminum or electrical tape grips too much.


----------



## robostudent5000 (Jun 4, 2011)

lookin' good! :thumbsup:


----------



## DM51 (Jun 4, 2011)

Great project!  

I think the boys in MMM would certainly appreciate this one - excellent machining. 

The idea of having 2 lights on your 'Rhino' mount is extremely sound - redundancy allows for any failure at what might be a critical time.


----------



## Lynx_Arc (Jun 4, 2011)

Bolster said:


> Tipping the scales at 1.4 oz, despite my best efforts to lighten it further. Everywhere else I looked, I thought, "I might need that for strength." So it stays the weight it is. The two ZLs w/ eneloops weigh +3.4 oz, and the boss was .8, so we're at 5.6 oz total. BUT we save using two ZL straps, 1.6 oz, so we're just .6 oz over strapping the lights on; I can live with that for the additional security.
> 
> 
> A footnote: Mounting the lights higher on the helmet would NOT have worked, I find. Since the lights need to shine more down than out, the higher you mount them, the more the front light would likely interfere with the beam of the hind light. While I got lucky (I hadn't modeled the beams), next time I design any kind of mount, I will definitely do that. The wider the beam, the more careful you have to be of placement.
> ...


 
You could have a flood beam on the front and a throwier one above it giving you blood options.


----------



## kevinm (Jun 6, 2011)

Nice work!


----------

