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Thread: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

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    Flashaholic JP Labs's Avatar
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    Default Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    I have been truly impressed with the variety and performance of the searchlight builds here, so I have been watching for a quality reflector, cheap. As you all probably already know, this is not easy! Well, I finally found one that seems pretty great for less than $100, shipped. I am excited. Now, I need to decide what to do with it. I would like the community's help to select a lamp/power supply, and with various other build questions that will come up. I hope this thread will be interesting to you, as well.





    Goals:
    I want to be able to put an obvious spot on clouds as first priority, and maximize visibility of the beam as second priority. I want to minimize spill. I live a mile from a small city with all its outdoor lighting, so I am working with a fairly bright nighttime sky.

    --
    EDIT to add a constraint on power, per post 18:

    Constraint:
    Run from car 12V battery power for at least 5 minutes. Run from idling car power for as long as I want to. Big, clamp on inverter or 12V direct are both OK.


    --

    I would love to have 20k lumens or more! But the 8000 or so (?) lumens from a '100W' HID is very accessible and easy. Would fewer lumens with a smaller source like a projector short arc be better for my goals?

    While I have studied many of your beautiful builds and learned what I can, this seems to be a unique project. I am leaning towards salvaging a lamp and ballast from a DLP projector. But not sure.

    My budget for a lamp & ballast is hopefully <$250. I could go higher for significantly better value. Portability is not terribly important, as this will go on some kind of tripod/turret mount, so anything heavy can go on the stand. 12V is preferred over mains power, but I do have an inverter. Modified wave. 750/1500W. Vector VEC043.

    From what I have learned here, I think the relatively large reflector means it can collimate a proportionally larger light source, so maximum surface brightness might not be so important for my goals. Maybe HID will be better for this, and short arc overkill that unnecessarily compromises beam power. I know it's a tradeoff, but for my goals, what do you think is the optimal lamp technology?

    Here's what I know about the reflector:




    From the markings, I think maybe it is an electroformed reflector from Phoenix, or similar. Can you help me ID it?


    • P/N P60-08
    • 16" Diameter
    • Focal length is about 2". You can see this in the pics - bulb is focused.
    • Rhodium plated from the RH marking.
    • Very smooth image, not a spun reflector, I think.
    • About 1mm thick at edge. Can measure if helpful
    • Outer surface looks to me like the ED reflectors. But I think they are Nickel, and a magnet will stick to mine. Are ED reflectors magnetic?


    As soon as it arrived, 2 days ago, I had to play. I started on an adapter to house a spare 35W HID to test it. I found that an old Air Conditioning R/D I had was a perfect OD to fit the reflector ID, so I cut it down on my Smithy and pressed my lamp into it:


    This fits nicely, and I use 2 o-rings to retain it while allowing adjust-ability.





    Note the AA battery for scale:


    The lamp is from a Harbor Freight Off Road HID that was on sale a while ago at 2 for $49. I think the outer glass tube is a UV filter. Is that correct?

    Here are a couple of beamshots.

    From about 100' away, not quite dark out yet:


    From about 4' off-axis:


    Zoomed in on cloud. Small spot already, so I am very encouraged! The spot is deformed here. If I hold the light by its base, the spot is round. But here, it is set into my sunroof opening, which slightly distorts the shape. Very sensitive!


    This light throws very much better than the 9" Autozone spotlight I modded with the matching HID. And I think it looks rather well collimated. So, already it makes HID seem like it might have a small enough source to work well.

    What do you think? What lamps should I consider for the final build? What would you do?

    I'm off to try to source a tempered cover lens, and then to the shop to start fabricating a mounting system.
    Last edited by JP Labs; 09-01-2014 at 08:16 PM.

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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    Just a quick reply on reflector Identification. Might be an Optiforms P60 here:

    //www.optiforms.com/parabolic.htm

    Find the P60 and go right to the VIEW button for different configs of the P60 and find the "-08" unit to get your specs.

    RH means: Electro deposited Bright Rhodium. That's a nice reflector!
    Last edited by BVH; 08-29-2014 at 11:17 AM.
    WWII 60" Carbon Arc (Sold), 1.6KW NightSun, 1KW VSS-3A, .8KW TrakkaBeam, 600W M-134 Light, 500W X-500-14s, 500W Starburst, 500W A120b, 450 Watt AEG German Leopard 1 Tank Light, 300W Locators, Megaray, 150W Communicator, Maxabeam Gen3, Pichel 75W Mini-Novas

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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    Very nice! A short arc would look awesome in that. Nice laser like beam. Now for you to find a lens to protect it!

    Sent from my SAMSUNG-SM-G730A using Candlepowerforums mobile app
    I Got tired of looking for the light at the end of the tunnel so i lit that bitch up myself! Convoy s2 365nm, Maxa-Beam Gen II, 55w hid/100w incan Vector Twin, Amondotech n30, vss-3A, Reylight Ti Lan v3, Helius Sigma 9, astrolux s41 219, Shadow JM35, BLF GT,

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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    BVH - Thanks for that link! The dimensions match as closely as I can measure. I think you ID'd it. So, it's a 2.35" focal length and it catches an 85 degree band of light from the source.

    Fritz - Thanks for the suggestion about short arc.

    I did find a lens. The local lighting shop had an extra 17" Tempered Glass lens lying around. When I answered the inevitable 'what model light' with a brief description of the project, the guy thought that was neat, so he gave it to me. I threw $5 in the coffee fund.

    I also started on the frame and mounting system. I'll get some pics up soon.
    Last edited by JP Labs; 08-29-2014 at 06:53 PM.

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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    Ok, pics. Here is the frame on the lens. Note this lens is just a flat piece of glass to protect it, not part of the optics. The lens has a gasket and a galvanized steel surround, with 3 spring clips. These clip over feet of the frame. Frame is 4130 tubing, overkill but on hand. Joining is silicon bronze, TIG brazed. I didn't clean the steel very meticulously, so the joints are a bit dirty, but it will be abrasive blasted and painted.



    Reflector mounted. Center ring of frame is clamped under the threaded nut that retains the center tube to the reflector, with an o-ring under it, so there is no load to deform the shape. There is a gap to the glass, about 1/2", so I can have forced air cooling.


    This is the horizontal orientation in which it will be mounted. Center leg up. Hopefully this will provide some protection for the reflector if something ever falls on it.


    Detail of reflector mounting:


    The 2 center tubes that the mounting ring are attached to will also support two pivots for mounting the whole thing to a yoke. That yoke will mount on a tripod.


    Pivots will go here, at the end of the 'V'. This is near the balance point. The glass is heavy.
    Last edited by JP Labs; 08-29-2014 at 07:15 PM. Reason: clarification

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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    Looks like excellent quality construction! You're moving right along. In my humble opinion, you really should go with a 500 to 1,000 Watt Short Arc system. Of course, the problem will be finding a compatible power supply and lamp system for a price within your budget. The power supply will probably be somewhat heavy also at that power range. I don't know if your modified Sine Wave inverter will cause a problem with a Short Arc PS or not. I bought a used Oriel universal 400 - 1000 Watt, Xenon and Mercury-Xenon PS with its' associated lamp housing off Ebay for around $1,000 a while back. The lamp housing contains the ignitor so only low (relatively) voltage cables run between the PS and ignitor. You could mount the ignitor to your framework so that the final high KV run is very short. Search Ebay using oriel arc lamp or oriel arc supply or other similar combos. If you use a Mercury Xenon lamp and PS, then you will not suffer loss of Lumens versus regular Automotive HID. Lumens per Watt are much higher with Mercury Xenon vrs Xenon. If you go with something in the range of 200 to 500 Watts, the used supplies on Ebay are quite a bit cheaper than one that supplies up to 1000 Watts. For cooling, search Vaneaxial on Ebay for high-CFM, small size fans. I can do some research on the vaneaxial unit in my Spectrolab Starburst 500 Watt light to see what the CFM is if you decide to go with something of that power range. I don't see an open space around the lamp in its' mount for cooling air to blow over? (assuming you go with a short arc system) This will be fun to watch. Post lots of pics!
    Last edited by BVH; 08-29-2014 at 10:23 PM.
    WWII 60" Carbon Arc (Sold), 1.6KW NightSun, 1KW VSS-3A, .8KW TrakkaBeam, 600W M-134 Light, 500W X-500-14s, 500W Starburst, 500W A120b, 450 Watt AEG German Leopard 1 Tank Light, 300W Locators, Megaray, 150W Communicator, Maxabeam Gen3, Pichel 75W Mini-Novas

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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    Yeah, I'm sittinhg her with a bag of popcorn, awaiting the outcome. I have a vested interest in this!!! My VSS-3 guts are looking compatible to this.

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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    Thanks for the encouragement, guys!!

    So, another (highly regarded!) vote for short arc, as big as possible. Re-reading some info from BVH, Ra, and Get-Lit last night, I now better understand that Mercury short arc is more efficient than Xenon, needs very precise adjustable mounting, and about the UV and explosion hazards. Nice guidance.

    BVH, you are taunting me with the potential of a better lamp. Good! I will try to execute something in that direction, instead of a simple HID kit set up. Decision made. Now, it is all about what I can find, and what is a good value. I will look into the Oriel lamps and universal power supplies you suggested. They are not out of the question. I will try to build this light to satisfy me the first time. (I can not ever allow myself to think about my relative with a movie theater, and my welder power supply).

    It is funny how, the more I put into a project in build hours, the more easily I can justify nice parts. In my twisted logic, each hour of fab time is worth about $50 of my precious free time. So, that is a $500 frame I spent most of yesterday working on, with materials. Seems a similar value is now justified for the heart of the beast. But, probably not 4 figures cost.

    Good suggestion to consider a configuration which will allow me to keep the HV leads short.

    I am more seriously considering the highest powered range of used video projectors for donors. These are rated up to 8000 ANSI Lumens OTF, so the lamps must provide more than that. But that approach is a gamble, relying on my ability to get the power supply to work once extracted. I think I could figure it out. I think there is a very significant benefit to using a projector. They have smart controls. I would try to keep the control system intact, using the temp sensor, fans, fan control, and airflow sensor to manage cooling and provide automatic shut down if something fails. Since a burst bulb could probably destroy my precious reflector, I think this is significant.

    BVH, about your cooling suggestions, great info. I am a Thermal Systems Engineer by trade, so I have some grasp of what is needed, but never worked with lamps like this, and experienced suggestions are best, so thank you. I'll look into this more.

    You are correct, there is currently no air path in my lamp mount. But it is hollow, and can easily be opened up on the end around the lamp to guide airflow over the lamp. A concentric aluminum tube could be welded on to better direct air at the lamp, or to mount a Pyrex tube that surrounds the lamp if necessary. While the test lamp (HID with bigger arc, so not as sensitive) is nicely centered because the current mount is a lathed part, I do not think it is good enough for a short arc source. The fit of my lamp mount in the reflector allows some wiggle, maybe 1 mm at the arc. If I go the short arc route, I think I would make a better lamp mount, with 3 axis adjustment. Maybe I can reuse this one, and add 'tilting screws' to turn the mechanical slop into a feature. I also have ideas about easily adjustable focal length.

    I do have a couple of gasoline generators (easily carried 900W and heavy 4500W) which could be used if the modified sine inverter is insufficient. I think single-RPM analog generators are sine wave by nature. But the inverter is preferred, so I can run it from the car more easily for parties.

    --
    Possible lamp option:

    I sent an email to my various friends asking for leads on big projectors. I learned of a working used commercial projector that uses a 330W Ushio NSHA Mercury Short Arc Lamp, which I might be able to buy. Service manual with schematics, too. I couldn't find specs for the lamp itself, so don't know lamp lumens. Anybody know?

    Is it reasonable to assume that this type of lamp can run vertical, without dying in a very short time, if well cooled?

    I am thinking of offering a couple hundred bucks for this projector, but maybe I should offer more. While that lamp is on the low end of what BVH recommends, it seems to be at the high end for single-lamp A/V projector power. It might be a very good value for short arc lumens/dollar, compared to buying a lab power supply and lamp separately. Maybe that used projector is worth a few hundred dollars to me in light power.

    The most reasonable used Oriel power supply I saw today with 500W capacity is $550 (Oriel 68811 on the big auction site) without a lamp, so the projector is probably worth a few hundred easily, by comparison, if it is suitable. 1KW Oriels are going for 3x that much.

    --

    Bill, I am VERY jealous of your VSS-3!! I wish I had such nice hardware to work with. In fact, your old thread about acquiring it was one inspiration for my 2 year online search for anything with a good reflector. It showed such things are sometimes attainable. But VSS-3 bring big money, and I never found one that seemed reachable, so I am building from scratch. I hope that the info shared here will help you in your quest to find a suitable lamp system to finally bring it to life! It is very hard to find a 'plug and play' recommendation, and such lamps need careful operation, thus my tendency to start with a salvaged projector system so everything plays nice, electrically and thermally. On the other hand, there are some really well documented builds here that either of us could duplicate, if time and funds allow. But they tend to be seriously high end stuff. CPF attracts the big dogs of the DIY lighting world, doesn't it? Nice to have them to learn from.

    --

    I'm off to work on the mounting hardware. Should have a few more pics later today.
    Last edited by JP Labs; 08-30-2014 at 12:04 PM.
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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    When I machine lamp adapters to fit over a lamp base, I shoot for about .0005" clearance and end up somewhere between .0005" and .001". I assume you will build some sort of 3 to 4-leg spider to provide support for and an adjustment mechanism for the front of the lamp you settle on. As long as the front is supported, that up-to .001" adapter clearance in the back will not result in any significant focusing issues. As far as upward shinning of the light (which we all want to do), most SA searchlights I have and have seen place the Anode (the bigger, more massive electrode) in the rear of the reflector so that when the light is pointed down from an aircraft, boat, what-have-you, the brunt of the arc flame which naturally rises is against it. Reverse that scenairo and there is some amount of tendency for some of the effect of the flame heat to be directed back towards the small, thin Cathode which does some damage and results in less lamp life. That's the theoretical and now to the real-world for us enthusiasts. I've talked a few times with my contacts at Advanced Radiation Corp (my obsolete lamp supplier) about this issue and I have specifically asked them about pointing my Spectrolab lights (they make the OEM lamps) up as much as 60 degrees above the horizontal and the answer is pretty much what I just wrote - You will technically shorten the life of the lamp but if you're starting with a 1000 hour lamp, you might still get 300 - 500 hours of good life out of it if it's life is spent pointing up. They do caution to not run it for excessively long times when only pointing up. They say pointing horizontal won't shorten life by much. With Mercury Xenon, the amount of cooling is more critical as you may have read in Getlit's Nightsword thread. Too much and you won't get full Lumens output.

    Are you after a Laser beam or a flood monster or something in-between?

    If you end up with a 500 Watt system (closer to 650 Watts total) then you're not going to want to run it off your car battery for more than a minute or so. 650/12=54 Amps of current. That's why I ended up making a 9-Cell, 100 Ah LiFeP04 portable battery. With that battery, I can run the 1600 Watt (1800 Total) NightSun for three, 20 minute sessions before needing to re-charge it. I also bought a 1500 Watt, Full Sine Wave, 24VDC input (22V - 33V input range) inverter so that I can power some of the 120VAC SA power supplies out in the field from the same battery. I need if for my TrakkaBeam 800 Watt PS and my M134 minigun light PS. The battery system is also great because there is no generator noise. You should hold out for a 500 Watt system. That is a great compromise between the 150-300 Watt systems and the 1000 Watt systems.
    Last edited by BVH; 08-30-2014 at 11:28 PM.
    WWII 60" Carbon Arc (Sold), 1.6KW NightSun, 1KW VSS-3A, .8KW TrakkaBeam, 600W M-134 Light, 500W X-500-14s, 500W Starburst, 500W A120b, 450 Watt AEG German Leopard 1 Tank Light, 300W Locators, Megaray, 150W Communicator, Maxabeam Gen3, Pichel 75W Mini-Novas

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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    I got the yoke built yesterday, and stuck it on a temporary tripod. Then I got invited to a buddies bonfire at his defunct 10 acre apple orchard in the country, where it is darker, so I just HAD to stop working and go play. I'll get a couple pics up soon, and more tonight or tomorrow.

    His place was once overgrown, and now it is carved up into a maze like network of grassy trails. Several of us regularly race around these park-like trails on mopeds and small (250cc or less ) ATVs and motorcycles. It is easy to get lost or disoriented. I ran the 35W HID test bulb for about 3 hours vertical as a beacon, and it was great.

    --

    Wow BVH, you are really helping me, here. I truly appreciate your interest and suggestions. I feel like a little kid who showed up at a park, and an NFL pro dropped by to teach me how to toss a football.

    Quote Originally Posted by BVH View Post
    When I machine lamp adapters to fit over a lamp base, I shoot for about .0005" clearance and end up somewhere between .0005" and .001".

    I assume you will build some sort of 3 to 4-leg spider to provide support for and an adjustment mechanism for the front of the lamp you settle on.

    I was not planning a spider. But I suppose a large lamp would require this for support. If I use a lamp with electrodes on both ends, I can do this.

    As long as the front is supported, that up-to .001" adapter clearance in the back will not result in any significant focusing issues. As far as upward shinning of the light (which we all want to do), most SA searchlights I have and have seen place the Anode (the bigger, more massive electrode) in the rear of the reflector so that when the light is pointed down from an aircraft, boat, what-have-you, the brunt of the arc flame which naturally rises is against it. Reverse that scenairo and there is some amount of tendency for some of the effect of the flame heat to be directed back towards the small, thin Cathode which does some damage and results in less lamp life.

    Can the lamp simply be installed with the large electrode, the Anode I believe, on the top? It seems that would help with the heat issue. Also, since the hot spot in the arc is formed at the Anode/big electrode, I think this would direct more light rearward towards the reflector. That is the way I envisioned setting it up.

    That's the theoretical and now to the real-world for us enthusiasts. I've talked a few times with my contacts at Advanced Radiation Corp (my obsolete lamp supplier) about this issue and I have specifically asked them about pointing my Spectrolab lights (they make the OEM lamps) up as much as 60 degrees above the horizontal and the answer is pretty much what I just wrote - You will technically shorten the life of the lamp but if you're starting with a 1000 hour lamp, you might still get 300 - 500 hours of good life out of it if it's life is spent pointing up. They do caution to not run it for excessively long times when only pointing up.

    After last night's fun, I really want to be able to run this completely vertical for extended times, as a beacon. With a quiet generator or idling car, I could do this. 30 degrees off vertical (the 60 you mention) could work but I would make trade-offs to be able to achieve vertical. If that is completely out of the question with short arc lamps, I could keep an HID lamp configured as a simple drop-in for beacon mode, with correspondingly lower power so it can run silently from a car for long times.

    They say pointing horizontal won't shorten life by much. With Mercury Xenon, the amount of cooling is more critical as you may have read in Getlit's Nightsword thread. Too much and you won't get full Lumens output.

    Yes, because the vapor pressure of the gasses inside will not climb high enough if the lamp is too cold, as I understood.

    Are you after a Laser beam or a flood monster or something in-between?

    Something in between. I don't really have any 'safe' targets more than a mile away, except maybe clouds above, so reach beyond that seems un-needed. From the discussions about 'Beam Power' (Get-Lit if I recall correctly), I think that is what I want to maximize. Highest beam power, with ability to put a nice spot at 1 mile, including on clouds above.

    If you end up with a 500 Watt system (closer to 650 Watts total) then you're not going to want to run it off your car battery for more than a minute or so. 650/12=54 Amps of current. That's why I ended up making a 9-Cell, 100 Ah LiFeP04 portable battery. With that battery, I can run the 1600 Watt (1800 Total) NightSun for three, 20 minute sessions before needing to re-charge it. I also bought a 1500 Watt, Full Sine Wave, 24VDC input (22V - 33V input range) inverter so that I can power some of the 120VAC SA power supplies out in the field from the same battery. I need if for my TrakkaBeam 800 Watt PS and my M134 minigun light PS. The battery system is also great because there is no generator noise. You should hold out for a 500 Watt system. That is a great compromise between the 150-300 Watt systems and the 1000 Watt systems.

    I have a 1920 hit or miss engine which needs a job. It's a 2 1/2 HP Stover. It makes nice noises, and could spin an alternator. This may wind up configured as an optional power source for parties. But I don't think it would have the oomph to power a 500W lamp. With a larger lamp, it could extend the runtime of a battery significantly, though. Generator or idling car would be acceptable to run big lamps.

    The large battery packs intrigue me. I also want to build an electric bicycle in the next year or so. At that point, I would have a 15 AH 48V or so LiPo pack to share. But that would be a later mod, not designed into the initial light's features.
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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    OK, here are a few quick pics as promised. I am short on time, but will add a few more later.

    Simple fixture to align the mounting pivots, which are simply bolts:


    Pivots installed in yoke:



    Temporary setup. Tripod is NOT robust enough - only temporary. Need a solid, wide one for safety! I purposely made the yoke extra tall, to leave room for electronics if needed. Can shorten easily if not needed.


    Another beamshot. Again, this is the test lamp, just a 35W CHEAP HID. Seems to be AC, not DC.


    The spot, from about 100 yards (EDIT - only 65 or 74 yards per Google Map, not sure which tree it was on the map):
    Last edited by JP Labs; 08-31-2014 at 03:09 PM.
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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    Absolutely the lamp can be installed Anode up. The brightest light source is actually right off the tip of the Cathode and it gets dimmer as the arc progresses towards the Anode. Technically, the brightest light source would be pointing directly out the front instead of back to the reflector. But again, in real world use, it is probably not going to matter at all for your use. Getlit could give you a much better answer than I can.

    The only SA I've seen without a spider is the marine ACR 150 and 300 Watt lights. They're mounted on boats/ships so very little vibration/shock potential. But if you were to remove the lamp for transport and reinstall it on-site and then not move the structure once it is running and hot, I think you'd be fine.
    Last edited by BVH; 08-31-2014 at 09:27 AM.
    WWII 60" Carbon Arc (Sold), 1.6KW NightSun, 1KW VSS-3A, .8KW TrakkaBeam, 600W M-134 Light, 500W X-500-14s, 500W Starburst, 500W A120b, 450 Watt AEG German Leopard 1 Tank Light, 300W Locators, Megaray, 150W Communicator, Maxabeam Gen3, Pichel 75W Mini-Novas

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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    Couple more.



    The furthest I viewed from was about 296 yards, and the beam was BARELY visible when aimed straight up.
    The furthest target (tree) I illuminated was about 435 yards, and the spot was still strong and bright. No pic, since it is on a neighboring property and I just touched it for a moment.

    This one is from about 130 yards away. Below shot's camera settings.
    F2.8
    1/2 second
    ISO1600
    Focal Length 4 mm
    Equivalent 35 mm Focal Length 25 mm




    I am realizing that I don't have any suitable (read: certainty that I won't blind or annoy anybody) long distance objects to illuminate that are not on roads, or straight up. The one mile away tree I can hit from home is along a road, so not for regular use. This is why I think my goal should be beam power, more than throw. I am not in an aircraft pattern, nor are the places I camp. And when we camp in the woods, it can be hard for others to find us. A beacon would be fun for such times.
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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    Have you considered a manual focusing mechanism? Shouldn't take much movement to go from full flood to tight laser like spot.

    Sent from my SAMSUNG-SM-G730A using Candlepowerforums mobile app
    I Got tired of looking for the light at the end of the tunnel so i lit that bitch up myself! Convoy s2 365nm, Maxa-Beam Gen II, 55w hid/100w incan Vector Twin, Amondotech n30, vss-3A, Reylight Ti Lan v3, Helius Sigma 9, astrolux s41 219, Shadow JM35, BLF GT,

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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    Quote Originally Posted by FRITZHID View Post
    Have you considered a manual focusing mechanism? Shouldn't take much movement to go from full flood to tight laser like spot.

    Sent from my SAMSUNG-SM-G730A using Candlepowerforums mobile app
    I was only going to have a screw and spring to set up the bulb, and to tweak it a little. Flood to spot would be a nice feature to add. I would want it to be mechanical, no focus motor. A lever or twist grip, maybe. Not sure how to do that.

    Any ideas?
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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    All you need to do is create a lamp holder/adapter movement mechanism that will give you roughly .250" of "Z" axis movement forward of the focal point to get flood. How does your lamp holder attach to the reflector? How can you make it slide forward and rearward? Secure it with a large ring nut? Can't tell from the first pics but it looks like you already have the capability. Is that a big ring nut I see and threads on the lamp holder?

    EDIT: I re-read post and I see you're using two O-rings to hold the focus position (Z axis) of the lamp holder. Are the 6 holes in the reflector hub ring threaded? Maybe drill and tap two opposing holes in the side of the lamp holder and make some type of "L" brackets with slots that will bolt to the hub ring and sides of the LH. Slot the L brackets and use the bolts to lock it down in any focus position you want.
    Last edited by BVH; 09-01-2014 at 09:16 AM.
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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    More Discussion About Goals:

    Playing with the light and seeing what I can do with it has been 'illuminating' for me. My goals are adapting.

    My own suburban home is not the best testing ground. Too close to the road.

    I set it up again briefly last night, at another buddy's house in the country, for a ~5 minute run just to demonstrate. I am a lot more comfortable doing that, than using it in my own suburban yard on a fairly busy 2 lane road. Every car that drives by can tell where its coming from. Its awfully nice to be able to pull it out and plug in to the car. And to have a silent power source for short runs (Suburban's Optima Yellow Top in this case).

    Certainly, grid power is ok for testing and home use, but my best opportunities to use this have been away from wall sockets at parties hosted by my friends. If I needed a heavy, noisy generator to run it, I could do that, but I don't think I would use the light very much. My light might become a 'once a year toy'.

    I want to be welcomed, even encouraged, to bring this to social events without annoying the host and guests. My generator is annoying.

    While it would certainly be more fun for me to build the biggest, most powerful setup I can, I have realized that I want 'grab and go' capability. Toss it in the car (well, Suburban) and bring it with me on short notice. It should not be a requirement to hook up the trailer and load my heavy 4500W generator. (It is too heavy for me to set in back of truck).

    While my functional goal for the light hasn't really changed, I think this means I need to add a constraint. I think I should limit power draw to a level that an inverter will support so I can run it from battery clamps for a few minutes, or with a 180A alternator, idling, for an hour or more.

    Having an HID lamp I can install for 'economy mode' would have achieved this for the smaller lamp, but I think most of my usage will be off grid, and I don't want to have to use the weaker lamp all the time. While I wrote above about it not being a problem to power a big lamp, I have realized that doing so would restrict my use quite a lot, and that generator noise would make me a lot more conspicuous and annoying to anybody nearby. I want to be as quiet as possible. So, my 'big lamp' choice should enable this.


    Additional constraint: (added to original post 'Goals' statement for clarity).
    Capability to run from clamp-on style inverter, or direct 12V, from alternator power.

    I think this means an A/V projector is my upper limit for lamp power, not a 1kW monster.

    Thoughts?
    Last edited by JP Labs; 09-01-2014 at 10:02 AM.
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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    Quote Originally Posted by BVH View Post
    All you need to do is create a lamp holder/adapter movement mechanism that will give you roughly .250" of "Z" axis movement forward of the focal point to get flood.

    1/4 inch should be do-able with the current mount. I think I read that de-focusing should always be done by moving the lamp rearward, so as not to cause the focal point to hit the lamp and overheat it. Glad you corrected my about that - defocus FORWARD from focal point, OK.

    How does your lamp holder attach to the reflector?

    It is a sliding fit, no threads or positive location, yet.

    How can you make it slide forward and rearward? Secure it with a large ring nut? Can't tell from the first pics but it looks like you already have the capability. Is that a big ring nut I see and threads on the lamp holder?

    EDIT: I re-read post and I see you're using two O-rings to hold the focus position (Z axis) of the lamp holder. Are the 6 holes in the reflector hub ring threaded? Maybe drill and tap two opposing holes in the side of the lamp holder and make some type of "L" brackets with slots that will bolt to the hub ring and sides of the LH. Slot the L brackets and use the bolts to lock it down in any focus position you want.

    I used that ring to clamp my bracket to the REFLECTOR (edit correction, originally wrote LAMP), so it is not available for focusing. But, I could extend the frame rearward and put a plate behind the lamp, with one bolt in the center. Then I could use springs to pull the lamp against the bolt. Turning the bolt would push against the springs and push the lamp holder forward.


    Last edited by JP Labs; 09-01-2014 at 10:30 AM.
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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    There is a problem with the way I built the glass cover into the light. The gap between my reflector and cover lens was added for airflow, but it causes 2 problems. Bugs get in, and light spill hits those who look towards the light, even if pointed almost straight away from the observers, because light bounces off the inside surface of the cover glass. I don't think this is safe. This is why I had the light set up to be above head level, so far. I will add a black baffle which blocks this, so all you see is the beam. It will probably just be a strip of aluminum flashing formed into a ring. positioned to cover this gap.
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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    Why defocus by moving lamp forward of focal point instead of rearward?

    I thought about this more, and the way I am picturing the light path, if I move the lamp forward of the focal point for flood, then the angles to the reflector become more acute (smaller), and the light will cross over itself. It seems that this would possibly result in a hot spot of focused light landing on the bulb. Defocusing by moving the lamp rearward would make the light bounce angles get bigger, so the light would diverge into a spot pattern without crossing over itself and making a hot spot.

    I don't claim to actually understand this, and may not be correct, above. But I have seen comments that support each technique for de-focusing. Can we discuss this more? I would like to understand.
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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    I'm going to try to start breaking my questions into shorter posts to make them easier to read and reply to. I realize that some of my posts are on the long side, and probably not easy to follow.

    Here's a question specifically about visibility of the beam:

    Does a smaller arc size reduce visibility of the beam for a given bulb lumen level?

    If so, might spending more on a 330W high pressure short arc mercury lamp actually hurt beam visibility, as compared to using an automotive HID running at 80W or so? I don't think so, but would like to make sure it's worth the extra effort and $$ to do the short arc, for my restated goals and power limit.

    I know this partially repeats something we discussed above, but I would like to better understand this trade-off. I need to make a firm offer on the projector soon if I want it. Can't decide what it's worth to me in performance terms.

    Further complicating the decision is that I still haven't been able to find a bulb lumens rating for the 330W Ushio NSHA Mercury Short Arc Lamp contained in that projector. I think it will be far more than from an HID, according to BVH's comments about efficiency, above.

    Can anybody confirm this with high confidence, specifically comparing that bulb vs. a "100W" HID bulb?
    Last edited by JP Labs; 09-01-2014 at 11:19 AM.
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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    One more post before I go. I found pictures of an 'equivalent' bulb to the Ushio in the projector. I think I could cut most of the reflector off with my wet tile saw, but it looks like it might be very difficult to remount after that. No good flange to put in a base.



    BVH's suggested lab supply and lamp options in the < 500W range would cost a bit more, but would not have this problem. I am realizing that is a pretty darn good suggestion. Maybe I need to give up on the projector idea.

    Any suggestions on how I might handle adapting a lamp like the one pictured above?
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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    My short answer is that getlit is the real go-to member for your beam visibility questions. From what I remember, beam visibility has more to do with the Focal Length of the reflector - short vrs med vrs long FL and I think the long focal lengths provided a better beam visibility and a more uniform beam cross section brightness.

    I have found that when I lump questions together in long posts, many do not get answered. I have started to number my questions 1-x and have had more complete responses.

    I wish getlit was on more. He could set you straight quickly.

    I should have asked if the projector lamp was a reflectorized unit. I've never figured out a way to use them, and I have purchased and then sold a few. Much easier dealing with brass or stainless cylindrical bases on conventionl SA lamps.

    I don't think your posts are too long.

    More editing: IIRC automotive HID and M.V. SA may be close to the same efficiency/Lumens per Watt. SA is around 35 to 40 LPW whereas HID and M.V. SA might be around 100 LPW. Seems to me that all other factors being equal, a shorter gap will result in a higher surface brightness (better throw) but lower overall Lumens.
    Last edited by BVH; 09-01-2014 at 11:41 AM.
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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    Rats, I wrote up quite a response but lost it to 'Token Expired', twice. Then I noticed the 'Restore autosaved content' button at the bottom when the blank response window showed up on the refreshed page. I never saw that before, and wish I had known about it one refresh ago.

    So, in case others don't know about it:

    If the forum loses your reply due to an error, look for the 'Restore autosaved content' button! You might get all of your work back!

    -----

    Maybe this is elementary to regular users....on to my post:

    Thanks, BVH, that is helpful. I appreciate your hanging out in this thread with me, and your info!

    I know I have been asking very specific questions that are hard to answer, but I'm interested in all aspects of making and using a light like this. If you guys have related thoughts, don't worry if they are a little off topic. I'm interested.

    I don't have very much experience with optics or electronics, so that's what I am asking about. I am no professional machinist, but I do like to build stuff, and would be happy to answer questions about that.

    On that note, I will explain a little more about how I made that frame in the next post.
    Last edited by JP Labs; 09-06-2014 at 12:36 PM.
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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    If I'm going to write a somewhat long post, I do a "preview" after each paragraph or so and maybe even copy that paragraph to the clipboard. I can usually get to the last saved screen by using the BACK button if I have done the "preview" thing.
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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    Ok, here's that frame again.



    While I used a TIG welder and a lathe to make this, it could be done with much simpler tools. A $50 MAPP gas torch, a drill press, and a file would go a long way. A Dremel, belt sander, or die grinder would be nice.

    I didn't 'design' this, in that it was not dimensioned and laid out as a drawing, or anything like that. I visualized what I wanted, built the first part, checked the fit, and did that again and again until it was done.

    First I made the mounting ring (#1). I did not make this from scratch. I started with a steel ring intended to be a pipe joint, which I got from the local scrap yard for $2. I just looked for something that had an ID as close to what I needed as possible, but smaller. I ended up having to remove about 0.100" radius material from the ID. I used a lathe, but a grinder would work fine. It doesn't even need to be precise, really. It gets clamped under a threaded ring on the reflector assembly that is quite wide. Hole needs to be big enough, but sloppy is OK.

    Once this ring was installed on the reflector, I needed to start shaping the frame.

    I started by setting my glass cover on a blanket, flat, on my bench. I put (3) 1/2" nuts on the glass cover to set my air gap, and then set the reflector on these, face down. I centered the reflector by putting my index fingers on opposite sides of the inside of the glass cover's edge band, and feeling it. This works surprisingly well, and is plenty close for the task. Easily within 1/16". This put the reflector just where I wanted it in final configuration, and made the ring (#1) the foundation of the frame layout. Everything else starts there.

    I built off this, directly. I hardly measured anything. I would hold a piece of metal up to the reflector, put a mark on it, bend it, and go compare it again. If it fit, I would tape it in place, with a clothespin or chunk of cardboard under it as a spacer. Coat hanger wire or pipe cleaners would be good to use to develop these shapes if you haven't done this before, so you won't have to bend and unbend the steel tubing to get it right. Then use the hanger wire as a template when you bend the steel.

    I simply bent the tubing in a vice, with a pipe stuck over the end to give me leverage on the larger ones (3/8 OD tube). For the smaller ones (1/4 OD solid), I would bend by hand and then bang with a hammer to get a sharper bend. I needed two of each part. I'd make the first, then use it as a template to make the second.

    I would leave each piece about 1/4" longer than I thought it needed to be! That let me adjust by trimming to make up for the inevitable errors and asymmetry that would show up when I brazed it, since I did not have a sturdy fixture. First timers might want to leave 1/2". Welds and braze joints warp when they cool. It also gave me a little room to grind an angle on the end of one piece, to match the side of the one it would be brazed onto.

    I made the main braces (#2, brazed to the ring) first.
    I bent the tube sections to rough shape, two identical pieces. I set the ring on a flat surface, set the 2 bent rods along side it, and brazed only the tips of the tubes together. Then I tweaked the shape to make it sit flat with equal heights on both ends, and brazed it onto the ring.

    Now, welding would be tricky here. The tubing is thin, the ring is thick. Tubing is Chrome Moly Steel, ring is stainless. It is possible to weld the two parts together, but not good practice, and the tube would tend to melt away before the ring was hot enough.

    Brazing does not care so much about different materials and thicknesses. You don't have to get things as hot, and you don't have to melt the parts you are attaching. You can attach combinations of mild steel, brass, stainless, copper, nickel, cast iron, titanium, and more.

    With a TIG welder, I use Silicon Bronze rods. This material is available for MIG welders, too, but I have not used it that way. Oxy Acetlyne brazing is an option, if you have that gear.

    The easiest brazing I have ever done is Silver brazing. It is strong, but the melting temperature is within the range of a MAPP Gas torch. A regular propane torch will not work well, get one for MAPP gas, or dual fuel. A decent Bernz-o-matic is only about $60. Chinese ones are 1/4 that much. You will need a small roll of Silver Braze wire from your local welding store, and some flux. And some kind of decent eye protection with tint. Not necessarily welding goggles, it is not arc-weld bright. But a little too bright for naked eyes. I have done it with sunglasses, not recommended though.

    I next made 2x of (#3) and brazed these in place. I did one side first, only on one end, the top! I can't final braze at the bottom with the lens in place, because the heat would wreck it. More on that in a minute.

    I held a tube in place, eyeballed the angle I would need on the end, reshaped it on the grinder, and repeated until it made good contact at one edge, and was within 1/16 or so everyplace else. That is close enough for this application, the braze will fill it. Strong enough for what it is.

    Finally, I did the shorter legs in the back. Not numbered in the pic above.

    This left me with a spider shaped frame that would stand flat on the bench, but each leg was a slightly different length and angle. Bend, grind, recheck until all are sitting close to the bench.

    For the attachment tabs (#4) I made a cardboard part first for fit, then hammered a scrap of stainless in the vise to match. 3 total.

    Here is where my technique would need to be modified a bit to adapt to using a MAPP gas torch. With TIG, I can pump a bunch of heat in, fast! To put it in appropriate language here, it is a 20 kW Argon arc lamp with no enclosure, and an arc length of about 4 MM.

    This let me quickly put a drop of braze on a joint to 'tack' it, wait a few seconds, then blast compressed air onto the part before it could melt the rubber gasket in the cover lens. Once they were all tacked like this, I could pull the lens out, and finish the brazing. (fast cooling a braze joint will weaken it! But these are only tacks, and once final brazed, will be fine.

    With a MAPP torch, you would need to figure out how to hold the attachment tabs in place without using the lens, during brazing. All else is the same. If the MAPP torch can't heat a big part quite enough, you can put it on a barbeque grille to get a head start. Or invite a friend and use two - simple propane for assist, even.

    Oh yeah, one last thing. Don't use stainless unless you have to! It is a pain to drill and cut. Mild steel is much nicer to work with. I only used stainless for the ring, because that is what I found in the scrap pile with suitable dimensions.
    Last edited by JP Labs; 09-01-2014 at 08:15 PM.
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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    Busy working week. I spent a little time playing with light baffling, but nothing worthy of pictures yet.

    I did not buy that big AV projector I mentioned above. Asking price turned out to be way too high. One digit too many.

    ---

    So, now I am looking at other lamp options again. I will try to summarize the various categories I am considering, with some key points I think I have learned here, and in my related searches:
    1. Laboratory mercury arc lamps like the Oriels BVH pointed me towards. Power level varies, but 100W is most common. Kind of hard to find, need to match possibly untested components to have a chance of reasonable cost, and still expensive. Probably a $500+ set up at 100W.
    2. XBO short arc mercury lamps in the form of microscope illuminators. Easier to find in running condition, cheaper that either option 1 or 3. Maybe $300 for either 100W or 200W. This is probably the most expensive option I should consider.... EDIT: Life only 200 hours for XBO lamps?!
    3. Motion Picture-type 'HMI Fresnel Studio Lights' that could be cannibalized. Entry cost for this type would be the highest, because there are no low powered options. Middle cost option for the power rating of the lamp. Highest lumen output in the ~500W maximum range I think I can run off a vehicle, I think. About $650 but you get a lot of lumens!
    4. Run of the mill DLP projector. Certainly the cheapest option, maybe $50 working, shipped. Pain to remove bulb from reflector, and then mount it precisely. Could afford to try more than once. Cheapest mercury short arc source.
    5. 100W rated HID is my baseline option, but I am hoping for shorter arc length and higher output. $60.


    So, there is quite a spectrum of prices, configuration, and outputs spanning my searches, now.
    ---

    I learned of HMI lamps, used in option 3 above, in the 'Superlights Shootout' thread, from this post. They sound pretty good.

    Complete HMI studio lights can be bought NEW, shipped from China unfortunately, for about $650 in 575W power. Housing, lamp, ballast, ignitor, lens, ready to use. 1200W is only a little more cost. Either would be tough for me to power from a vehicle, but 575W is probably possible if idling with all 12V stuff turned off. These entire studio spot lights cost less than buying a separate HMI lamp, ignitor, and ballast, it seems. The HMI bulbs used in them are single-ended mounting style, and output 49,000 lumens @ 575W!! But I don't know arc length or luminance, and didn't find the info easily. I need to find out more about these lamps! Way above my desired cost, but new, ready to run, and 49k Lumens? What am I missing? Probably, the fact that buying it from China may not go well. They do offer a 14 day money back guarantee, with free return shipping. But, it takes more than 14 days to get here, so how can that work? I think the cost is too high, and risk too high, for me to chose this. It would be very nice to find just the lamp and ballast/ignitor for a fraction of the total light's cost, though!

    One thing I like about this 'pseudo single-ended' lamp configuration is that it looks easier to cool the electrodes adequately, without overcooling the lamp's gas mix. As BVH alluded above, on a double-ended lamp you need to cool the far electrode without overcooling the bulb. Tricky.

    I don't think I can link to auctions, but if you search for "Pro As arri HMI Fresnel" on a large auction site, you will see them, including pics of the lamp configuration.

    ---

    The microscope illuminators seem more accessible than laboratory short arc lamps like the Oriels, both in price, and in being able to buy a complete, running set up. I am not sure if I could cool the ends adequately, without overcooling the gas mixture, in axial mounting configuration.

    I haven't found a combination of 'Tested, good parts' to set up even a 200W Oriel mercury arc laboratory lamp with ignitor & power supply for much less than $800, yet. The ignitors seem to be the expensive/scarce component. I will try to keep watching for a deal. I am impatient to find my final light source, though!

    The microscope illuminators could be bought or put together for less than half that cost, maybe $300 or a bit more, using tested working components. So that might possibly be an option.

    HBO 100/2 and HBO 200/4 seem to be the most common ones available. These two similar-sounding lamp options are very different, in terms of intensity and output.

    • Classically referred to by the registered trademark as HBO lamps (H for Hg or mercury; B is the symbol for luminance; O for unforced cooling)
    • I think I like the HBO 200W better, due to output, but the arc gap is about 9 times bigger than the 100W!!
    • Lumen output is 4-5x as much for HBO200 vs HBO 100. But only 1/2 the lumens/watt of the HMI lamps, and 1/5 the output, for 1/2 the price.
    • Luminance is DRASTICALLY better for the HBO 100W vs 200W.
    • EDIT: HBO lamp does not require forced cooling, but lamp life is only 200 hours and 100 starts?! This article gives a pretty thorough and interesting description of HBO lamp technology http://zeiss-campus.magnet.fsu.edu/a...ercuryarc.html


    Which to maximize for my build, luminance, or lumens? I think I need to find the best compromise of both. But where is the balance?


    Question:

    With my larger reflector, which of these HBO lamps do you guys think would be more suitable for generating a highly visible beam, as opposed to max throw?




    .
    Lamp
    HBO100/2
    HBO200/4
    Nominal luminous flux 2200 lm 9500 lm
    Luminance 170000 cd/cm² 33000 cd/cm²
    Luminous intensity 260 cd 950 cd
    Arc Length 0.25 mm 2.2 mm










    Please feel free to share your thoughts.
    Last edited by JP Labs; 09-06-2014 at 04:52 PM. Reason: Corrected XBO to HBO in several places. Added HBO definition.
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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    I found an interesting, 1967 NASA report about remote sensing illuminators, including a bunch of Short Arc Lamp info. I didn't realize lamps like the XBO and HBO short arcs had been around that long. I have only skimmed the report, but this is where I found the arc length data (p27/166), for example: Link to NASA Report PDF
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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    Here's a useful description of mounting and thermal considerations for the HBO lamps, from the above linked article:

    As discussed above, mercury arc lamps contain a precisely measured amount of metallic mercury within the envelope, and they are filled with argon or xenon, which acts as a starter gas as the mercury vaporizes. When the lamps are cold, small droplets of mercury can often be observed on the inside walls and the gas pressure inside the envelope is lower than the ambient pressure of one atmosphere. Once the lamp is ignited, the mercury vaporizes over the course of a 5 to 10 minute transition phase. During this period, the lamp is operated at higher than normal current, requiring the anode to be positioned at the bottom of the lamp to ensure proper vaporization of the mercury. For this reason, the ferrule sockets in a mercury lamphouse have different diameters (one smaller than the other) to enable correct positioning of the lamp, which itself has a larger ferrule on the anode end of the tube. Thus, mercury arc lamps are positioned vertically within the lamphouse with the anode pointing toward the bottom and the cathode pointing upward. Operating a mercury lamp at an angle exceeding 30° from the vertical position deflects the arc toward the quartz envelope resulting in uneven heating and premature darkening of the bulb. Several mercury lamp designs incorporate a reflective coating on part of the envelope to speed the vaporization transition phase and to improve thermal distribution. Because the envelope temperature influences the internal mercury pressure to a significant degree, mercury arc lamps are sensitive to airflow over the bulb and this aspect must be carefully controlled by the lamphouse.
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    Flashaholic JP Labs's Avatar
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    Default Re: Scored a Nice 16" Parabolic Reflector. HID or Short Arc? Test Beamshots w/ HID.

    More on Projector lamps:

    Many DLP projectors use UHP lamps, with a nice 1mm arc length. Very high luminosity. So, I investigated UHP lamps more deeply today, to see what I might get myself into. It is becoming evident to me that they have critical cooling requirements which would be too difficult for me to reliably duplicate with a lamp extracted from a projector. The entire quartz envelope must be kept between 1190k and 1400k. Risk of bursting lamp and ruining my reflector during testing would be high, unless I err on the side of overcooling, in which case output will be weak, and the lamp will turn black due to recrystallization on the cooler parts of the quartz.

    Another point for BVH; I am beginning to see why he never pursued projector lamps, and gently tried to steer me away from them. HBO lamps and HIDs are less intense, but do not have this same level of risk.

    ma sha1 made UHP work in his Mega Blaster and Moon Blaster, so it can be done. But the photos from those thread are gone, and I don't have any idea how he cooled the lamp. I don't dare attempt it myself without more info. I think it is unlikely I will hit the proper operating temperatures, and it is not really possible to measure.

    If anybody has experience running UHP out of a projector, I would love to hear how they cooled it!

    The more I learn, the more difficult it is to pick a better lamp than HID! It is hard to beat 100w HID with similar output in a smaller arc, without spending a LOT more. I can't see a way, yet.

    More info about UHP thermal design here, for anybody interested, p.16: http://koti.kapsi.fi/jahonen/Electro...f/UHP_Lamp.pdf
    Last edited by JP Labs; 09-06-2014 at 02:13 PM.
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