Reflector design?- Mtbr.com
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  1. #1
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    Reflector design?

    Not got around to ordering parts for my new light builds and have been thinking of other ideas.

    Is there a way of designing a reflector to improve throw?

    Just throwing ideas around but was looking at an XHP70 for a single LED helmet light. My idea was to make the reflector as part of the housing with a screw on lense to protect the LED so that I could have the heat sinking directly from the light.
    The rear of the design would need some jiggling but should be easy enough to design.

    I'm thinking single LED/long throw helmet light..

    Is there a tool that can be used to design this? Or is there a base shape to start with?

  2. #2
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    You need to generate a deep parabolic curve. You can find info about them and the formula to calculate that on the web or you may have a CAD tool to define one. The focal point of the parabola needs to meet on the phosphor surface of the emitter. You'll still get pretty good spill, especially so with a large die like the XHP70.

    I programmed one using Fanuc Macro B on a Nakamura lathe just to test out the formula but never got the chance to actually cut one. The calculations were such that the CNC control really bogged down and the feedrate got real slow near the bottom of the curve. Now I no longer have access to a CNC lathe so have not pursued it further.
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  3. #3
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    I'm with vanv on the trying to create throw with such a large emitter. I'd be more included on just buying a tight spot optic for xhp70 and building the light around that. Multi die emitters seem to be challenging to do much with unless the optics or reflectors are quite large in comparison to what we use with xm-l2/xp-l

    Sent from my XT1565 using Tapatalk

  4. #4
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    I have played around with an XHP70 and a 35mm Fraen narrow reflector for the MC-E emitter. It makes a pretty nice beam. Anything smaller (20mm Regina reflector) just gets too wide. A 20mm reflector with an aspheric optic in front might tighten it up.

    If you are driving an XHP70 hard, you need a fairly large housing to shed the heat. Going with a 35mm reflector works because of that.
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  5. #5
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    It it the FRC-N1-MCE-0R you're using Van? Would prefer to use a stock item if possible..

  6. #6
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    Yes, that's the one. I'd go with that over the Ledil Iris for the helmet light you mentioned in your other thread. The Iris is a huge chunk of plastic and quite heavy compared to the Fraen and does not make any better beam.
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  7. #7
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    Quote Originally Posted by Vancbiker View Post
    Yes, that's the one. I'd go with that over the Ledil Iris for the helmet light you mentioned in your other thread. The Iris is a huge chunk of plastic and quite heavy compared to the Fraen and does not make any better beam.
    Ah yes, good point. I can't seem to find any to buy yet though...have emailed Fraen to see if they've still got some. Nice man @ Ledil is sending me some Iris samples to have a play with too.

  8. #8
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    I'd send you some, but I've only got two left with one spoken for already.

    One of my sons ordered a couple recently for a build he is doing. I think he went through Arrow Electronics. I don't know if they sell in the UK though.

    One other thing about the Iris is it has a big "hole" in the center front of the optic. Hard to clean that out when muck gets in it. Pretty much needs a cover glass to keep it clean.
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  9. #9
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    One other thing about the Iris is it has a big "hole" in the center front of the optic. Hard to clean that out when muck gets in it. Pretty much needs a cover glass to keep it clean.
    I've got some 40mm glass lenses that would sort that.
    They arrived this morning, they're a big beast and 20g's each with the holder.

    I'll see if Arrow are in the UK

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