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  1. #1
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    Lasercut light for everyman

    Hi guys

    I've been hanging around this forum for some time now and have bodged together a few lights along the way with your help and support. One thing I've noticed is that there are a handful of fantastic engineers out there who mill and turn miniature works of art, plus a shedload of folks like me who haven't touched a machine tool since school.

    So, I set out to design a light unit that anyone could make but wouldn't be completely disgraced alongside some of the beauties we see on this site. Hammond boxes are functional, but they don't really float my boat.

    This is Version 1. It's not perfect (yet) but as it nears completionI figured it was time to share.



    As a light it doesn't break any new ground. It's the standard 2 x XPG R5/Regina/Bflex combo that has been seen many times on these pages. It's the housing that's interesting.





    I started from the premise I didn't have a milling machine or lathe, therefore I couldn't really remove metal from a solid block of ali. However with hacksaw, dremmel, drill etc. I could work 2mm sheet metal effectively. It knew my light needed cooling fins and 2mm seemed the right thickness for that. I started to wonder what would happen if I laminated thin pieces of metal together to build a light in layers. I modelled it in Sketchup and it looked OK. I drew up the profile of each piece in CAD and made a mock-up in layered plastic and it looked ok too.

    In the end I was too lazy to hand cut each piece as planned and instead a friend of a friend laser cut a couple of sets for me. This is what the bits look like.



    The holes in the fins serve several purposes. They shed a few valuable grammes, improve airflow, increase the surface area (a bit) but mainly are for bling. All the parts are clamped together with M3 stainless screws, with copious amounts of thermal paste between layers.

    The front bezel was a right royal PITA and I won't make the next one like that, I'll probably laminate that too but that means a bit of a redesign.

    The 'wings' on the side look a bit ugly but make for a simple helmet mount using velcro strap. I haven't been out with it yet, but prancing round the house with it on my head I think there's enough up/down adjustment by moving the lamp forwards and backwards round the curve of the helmet.

    I planned to make the spare bits into a bar light and bought some extra XPG's and a variety of optics at the same time. However since then XML's have appeared and I'm tempted to try a pair of them with a B2flex. Unfortunately I paid less attention to how I'm going to mount that one; it's not as simple as bolting through the bottom and I might need use of Dremmel, file and saw to fabricate a solution. Ideally I need someone to machine me a nice o-ring clamp thingy.

    This one's a bit porky at 78g complete but I'm confident I can take 15g out of that fairly easily. The stainless screw alone weigh 12g so I'll look at using fewer, and maybe aluminium screws, next time. Can't see any way to get down to real weight weenie level but console myself with the knowledge I've probably got more surface area to play with.

    Anyway, I hope you like it and that it inspires some new builds. I've got several ideas in mind for when the wife's not looking!

  2. #2
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    Over the years there have been a few of these plate lights. I like the idea personally, but you get the "all those junctions reduce cooling efficiency" comments.
    I never bought into there being too significant of a loss.
    Plus the plates make the light totally modular. You can extend or shorten the body to accommodate larger/smaller drivers. Spacing plates can be added to lengthen front for longer optics/reflectors.
    Most lights we build are set up for one specific star and lens combination.
    Troutie had issue with this when the square mcpcb's from cutter were something like a half millimeter thinner than the rounds he originally had in his 6x XPE light.

    The pins in those wings for the velcro is something I don't think I have ever seen.
    So extra point for originality.

    Sorry about the commentary, but I just think that style of light design rocks.
    Keep it up. :

  3. #3
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    Very cool Thanks for sharing.



    ***

  4. #4
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    Quote Originally Posted by odtexas
    Over the years there have been a few of these plate lights. I like the idea personally, but you get the "all those junctions reduce cooling efficiency" comments.
    I never bought into there being too significant of a loss.
    Plus the plates make the light totally modular. You can extend or shorten the body to accommodate larger/smaller drivers. Spacing plates can be added to lengthen front for longer optics/reflectors.
    Most lights we build are set up for one specific star and lens combination.
    Troutie had issue with this when the square mcpcb's from cutter were something like a half millimeter thinner than the rounds he originally had in his 6x XPE light.

    The pins in those wings for the velcro is something I don't think I have ever seen.
    So extra point for originality.

    Sorry about the commentary, but I just think that style of light design rocks.
    Keep it up. :
    Yeah, I wondered about the loss at the interfaces which is why there's a fair bit of metal in there. I think I left about 5mm each side of the driver housing to increase the area of the junction and used a fair bit of thermal paste between plates. It feels to the touch like it warms up uniformly. Indoors in a warm room, running at 1A, it takes about 4-5 mins to trip the thermal sensor set at 50 deg. Haven't tried it outside yet.

  5. #5
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    BTW
    If you haven't covered the threads on the bolt with a sleeve the threads can eventually cut through the velcro strap.

  6. #6
    help with the zip please
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    Nice work jez.
    I looked at doing a similar thing before bought the drill press but as odtexas says you get all those negative comments and they were enough for me to not even attempt.
    I'm really pleased to see you have and with such good results.

    Love all the little extra holes for cooling and weight loss.

    Looks great, well done

    Edit, love the idea of the side mounts for the helmet straps.

  7. #7
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    I've never seen one of these before.. i think its excellent..

    Only one question springs to mind, is it waterproof?



    Nice helmet... i also have it in blue...
    Last edited by Goldigger; 01-27-2011 at 05:52 PM.

  8. #8
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    Great light. I had a layer light mapped out but liked the price look/shortcut aspect of the Marwi housings.

    There is no question that a solid chunk of Al has no interfaces and so less total resistance. However, the amount of increased resistance added by interfaces of the plates, I think is overblown. Especially in a design like this one.

    As long as you aren't pushing minimal area, weight, and size for the thermal load you can err on the side of more contact area to compensate for a bit less metal-metal contact per unit area of cross section than solid metal has. Tight bolts and thermal paste with the area of the plates has got to be as more metal-metal thermal path plus the metal-paste-metal thermal path as the 1/16" thickness of a Marwi shell, and those work very well. More contact = less thermal resistance, and at some point, diminsihing returns set in. Laser cutting would minimize distortion of the plates and bolts would help the rest, so polishing to a flat surface would gain almost nothing. If drilled and dremeled, lapping would be good to remove tooling distortions for more metal-metal contact.

    Paraphrasing Zaphod, I like it so much, I think I'll steal it. Well, revisit my plan after I finish projects underway.

  9. #9
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    JezV, THAT IS NICE and looks much nicer than my new light (twin Regina /bFlex).

    I did make a copy of a Hope light a few years ago when I only had a Dremel and made it in layers and found that as long as it's all bolted together nice and tight it was just as good as a solid lump and that light still works today.

    The watch strap mount idea is great. But how did you get it so low profile with a bFlex in there ? is it laying flat? and if you dont mind can I ask what the dimensions are?

  10. #10
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    Quote Originally Posted by odtexas
    BTW
    If you haven't covered the threads on the bolt with a sleeve the threads can eventually cut through the velcro strap.
    Thanks odtexas. Although it doesn't show on the photo the bolts are sleeved with some thin aluminium tube I got from a model shop. TBH I did it mainly because it looked better, but sounds like it has a functional benefit too. Next time I think I'll try an use an aluminium rod and thread one end, rather than the bolts. Would be neater and lighter. As you can see from the pics, there's a bit of finishing off to do such as trimming ends of the bolts

  11. #11
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    Quote Originally Posted by Goldigger
    I've never seen one of these before.. i think its excellent..

    Only one question springs to mind, is it waterproof?



    Nice helmet... i also have it in blue...
    Cheers GD

    I think the body should be watertight. The plates are dead flat and I used Arctic Silver paste between layers, which is pretty sticky stuff. The switch is IP68 and the cable gland's sealed with a smidgen of silly cone.

    The front bezel? No. its made of 1mm aluminium plate and only the edge of it sits against the heatsink. The ID is a 20mm and it sits tightly around the stars, which provide lateral location. I thought it was flat after lapping on wet and dry paper, but when the LEDs are on I can see light around the edges so obviously more work to do there. The lexan front lens is epoxied so again should be fairly watertight.

    Interestingly the bezel heats up with the rest of the body so its either radiation from the LEDs or there is still a good conduction path.

  12. #12
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    Great design. The straps things are a good idea. They increase surface and serve as a support at the same time.

  13. #13
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    Quote Originally Posted by yetibetty
    JezV, THAT IS NICE and looks much nicer than my new light (twin Regina /bFlex).

    I did make a copy of a Hope light a few years ago when I only had a Dremel and made it in layers and found that as long as it's all bolted together nice and tight it was just as good as a solid lump and that light still works today.

    The watch strap mount idea is great. But how did you get it so low profile with a bFlex in there ? is it laying flat? and if you dont mind can I ask what the dimensions are?
    You flatter me - your lights were one of the inspirations for this project. I think your latest light is fantastic - I'm a fan of the fins

    The profile isn't as low as it looks. If you look at the picture of the rear you can see it's deeper at the back. The shot of the plates shows it a bit clearer - there's a Bflex-sized hole that runs through the housing. The dims are 48mm wide (excluding the wings), 30mm deep and 45mm long. The length is governed by the switch dims. With a shorter switch it could easily be 4mm less.

  14. #14
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    Hey Jez, I think it is a great design and well executed.
    Great job!!!
    Also a fan of the strap mounts. I may have to borrow that....= )
    Look, whatever happens, don't fight the mountain.

  15. #15
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    Very nice!! Creativity at play.

  16. #16
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    A modular design like that would be a great test bed for heat sinking add or remove slices until you get it right

  17. #17
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    I like it, alot! Seems like a great way of getting that CNC'd look without having a lathe. I'm all for Hammond boxes and 1in.sq tubing, but they aren't the prettiest of things

  18. #18
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    Quote Originally Posted by troutie-mtb




    A modular design like that would be a great test bed for heat sinking add or remove slices until you get it right
    Cheers Troutie, you've brought a tear to my eye!

    Seriously though, I hadn't thought of testing heatsinking by adding/removing slices. Another great idea

  19. #19
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    Quote Originally Posted by mattthemuppet
    I like it, alot! Seems like a great way of getting that CNC'd look without having a lathe. I'm all for Hammond boxes and 1in.sq tubing, but they aren't the prettiest of things
    Exactly my thoughts. I've been riding the last year with a triple XPE inside a bit of 22mm copper pipe and whilst it worked it looked out of place against the nice XTR kit on my bike.

    Actually the pics don't really do it justice. It has quite a nice polished finish in the flesh but the photo's make it look rougher than it is. I've a few details to tidy then I'll see if I can take some better ones in daylight.

  20. #20
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    Quote Originally Posted by JezV
    it looked out of place against the nice XTR kit on my bike
    well, I don't quite have that problem, but still..

  21. #21
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    Quote Originally Posted by mattthemuppet
    well, I don't quite have that problem, but still..
    Sorry, that sounded more showy than intended

  22. #22
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    don't worry, I'm just pulling your leg

    Still, it's a nice problem to have!

  23. #23
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    Ok, so its been over a week since the last of the silicone was fully cured and at last I've had a chance to use it on the bike. Been out for an hour with just the helmet light for illumination (only got one 11.1v battery at the mo'). So, what do I know now that I didn't know yesterday?

    1. The heatsinking works well. After an hour at full power the case was cold to the touch. It was a chilly night (7 deg C and windy) but as it gets plenty hot indoors it is obviously shedding heat effectively.

    2. The strap mount works well but there's not enough adjustment. The lamp needs additional padding to raise the front edge a few degrees.

    3. 2 x XPG/regina @ 1A is not really enough light, at least on its own. Makes a brilliant light for the road but crossing an open field, and again cutting across the corner an airfield, there wasn't enough range and I got disorientated. I am also sure I could outride the beam on a fast downhill. I expect it would be punchier at 1.5A and I am sure it'd be better supported by a good bar light. In wooded singletrack it was adequate. Never tried the low setting; might be useful for commuting or battery saving.

    4. Riding with just a helmet lamp makes it very difficult to see the ground contours. The light is so close to your eyeline that the bumps cast no shadows. Again, less of an issue with a bar light as well.

    5. The weight (78g) was not an issue and I never noticed it once I had the helmet on. Could be because is is mounted low and central. However I don't feel the need to rush into the garage and hack 20g off it.

    In conclusion, I am pleased with the performance of the laminated body but slightly underwhelmed by the light output. I've enough bits to make another which I had planned to drive with a B2flex and fit to the bars. I might instead buy a pair of XML's and one of Goerge's Lflex's when it becomes available to really give it some oomph.

    Or make a new body with a pair of XML's and Iris's.

    Or one of Cutter's MR16 triple XML boards with a Cute triple and H6flex.

    Or, or, or...

  24. #24
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    You comments regarding output are interesting. I found that the XPG really comes alive around 1300mA but at 1 amp was only just adequate for riding and I always felt I was out riding the beam a little.

    I also found that using warmer tint leds for the helmet light really helped with improving the contrast of the terrain and being ably to see contour changes.

    Excellent work on the light however. Great concept.

  25. #25
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    The insufficient light comment is surprising to me. I understand that what works for some, doesn't for others. I love the amount of light from my dual XP-G/ Regina light. I have not done a lot of trail time with it yet, but what I have done it rocked! It is not far off the brightness of my dual MCE (K bin, so not the highest) with Fraen reflectors.

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