First off, please forgive if I have missed a "sticky" - I have used the search button but cannot find any info on this particular bit of fun.
Having prepared (re-silvered) the reflector and finally managed to get everything ready, I start to assemble the lamp into the reflector.
I hook it up to the power supply and by means of holding the wire from the bottom of the lamp, I can move it about a bit to find the optimum focal length.
Projector on and away we go.
Ok, I can find that even tiny amounts of movement make quite a notable difference to the brightness - my problem is how to actually mark the position. On my projector, the lamp is a little way in - so easily marking a nice fine line with a sharpie is more than a little easier than it sounds.
Ultimately I find by pure luck that when the edge of the silvered part of the lamp tube is at the very bottom of the reflector base - it is in alignment - result.
Well *sort of result*
I spent a couple of hours trying to find a way to hold the lamp dead central to the reflector without getting anything nasty on the lamp glass
Is there are "suggested easy way to do this" ?
I finally manage to do it by working on the basis I shall clean the lamp with white spirit - and I can then plunge the tip of the lamp into a large luimp of plastercine which goes over the top of the reflector. This holds the capsule centrally AND at at the right height.
Next bit of fun was the cement.
I mixed it up but when I started squidging it in, it seemed to fall inside the lamp if too runny - and not really "stick" the the glass if a bit dryer. Trial and error managed to get it "sort of right" - but still made a huge mess trying to bond the two parts together.
Again, if someone can show me the simple way to do this - that would be wonderful - picking semi-dried cement from the inside of the reflector and off the capsule isn't a great joy 🙂
Lastly, is there an alternative to the cement? Even after several hours it seems a very weak bond - such that when GENTLY tightening the connecting wire, it started to break the cement.
Plaster of paris? Interna; / external filler? Fire cement? there must be something out there which is reasonably cheap, strong and heat proof.
Again, if I have missed a sticky, I apologise - would someone please be kind enough to point it out 🙂
Have fun
Mark
Having prepared (re-silvered) the reflector and finally managed to get everything ready, I start to assemble the lamp into the reflector.
I hook it up to the power supply and by means of holding the wire from the bottom of the lamp, I can move it about a bit to find the optimum focal length.
Projector on and away we go.
Ok, I can find that even tiny amounts of movement make quite a notable difference to the brightness - my problem is how to actually mark the position. On my projector, the lamp is a little way in - so easily marking a nice fine line with a sharpie is more than a little easier than it sounds.
Ultimately I find by pure luck that when the edge of the silvered part of the lamp tube is at the very bottom of the reflector base - it is in alignment - result.
Well *sort of result*
I spent a couple of hours trying to find a way to hold the lamp dead central to the reflector without getting anything nasty on the lamp glass
Is there are "suggested easy way to do this" ?
I finally manage to do it by working on the basis I shall clean the lamp with white spirit - and I can then plunge the tip of the lamp into a large luimp of plastercine which goes over the top of the reflector. This holds the capsule centrally AND at at the right height.
Next bit of fun was the cement.
I mixed it up but when I started squidging it in, it seemed to fall inside the lamp if too runny - and not really "stick" the the glass if a bit dryer. Trial and error managed to get it "sort of right" - but still made a huge mess trying to bond the two parts together.
Again, if someone can show me the simple way to do this - that would be wonderful - picking semi-dried cement from the inside of the reflector and off the capsule isn't a great joy 🙂
Lastly, is there an alternative to the cement? Even after several hours it seems a very weak bond - such that when GENTLY tightening the connecting wire, it started to break the cement.
Plaster of paris? Interna; / external filler? Fire cement? there must be something out there which is reasonably cheap, strong and heat proof.
Again, if I have missed a sticky, I apologise - would someone please be kind enough to point it out 🙂
Have fun
Mark
Cement question??
Hello,,,
I saw an old post relating to lamp cement. Did you ever find a lower cost altertitave to use?? Did you try regular Furnace cement? Is there a generic version of the white cement that seems to be used in cementing the factory Lamps in??
Please reply here and feel free to email me @
Stuffyhead1@aol.com
Many thanks in advance.
Bohanna
Hello,,,
I saw an old post relating to lamp cement. Did you ever find a lower cost altertitave to use?? Did you try regular Furnace cement? Is there a generic version of the white cement that seems to be used in cementing the factory Lamps in??
Please reply here and feel free to email me @
Stuffyhead1@aol.com
Many thanks in advance.
Bohanna
Cement answer
If you just use regular "fire cement" - in the UK you can find it in "Wilkinsons" in the adhesive / cement / mortar section. It is the stuff you use to mortar the joins in fireplaces etc.
Works well, sticks to the glass well and is ready mixed - it dries when exposed to air.
Very inexpensive too.
As for alignment, still find that a bit awkward to be honest - as although making a mark when removing the original helps, it is hard to be accurate to a tenth of a millimetre (100 microns), and that much difference is notable in terms of brightness difference.
To get it "about right", I just look in the reflector and adjust to get the whole of the reflector "filled with the image of the bulbous part of the bulb".
On another project (huge metal reflector playing with a 400w lamp), I mounted the bulb end with fire cement into a threaded brass adaptor - and then fitted a mating socket on the reflector.
I then secured the bulb with an assortment of clampsand very gently rotate the reflector to adjust the focus until it was as good as I could get. Bulb left to cool and then cemented around the threads to lock it in place.
Mark
If you just use regular "fire cement" - in the UK you can find it in "Wilkinsons" in the adhesive / cement / mortar section. It is the stuff you use to mortar the joins in fireplaces etc.
Works well, sticks to the glass well and is ready mixed - it dries when exposed to air.
Very inexpensive too.
As for alignment, still find that a bit awkward to be honest - as although making a mark when removing the original helps, it is hard to be accurate to a tenth of a millimetre (100 microns), and that much difference is notable in terms of brightness difference.
To get it "about right", I just look in the reflector and adjust to get the whole of the reflector "filled with the image of the bulbous part of the bulb".
On another project (huge metal reflector playing with a 400w lamp), I mounted the bulb end with fire cement into a threaded brass adaptor - and then fitted a mating socket on the reflector.
I then secured the bulb with an assortment of clampsand very gently rotate the reflector to adjust the focus until it was as good as I could get. Bulb left to cool and then cemented around the threads to lock it in place.
Mark
Re: Cement answer
Hey Mark,, thanks for the responce . I have been experimenting with a retrofit metal halide in the sanyo projector. I have decides to fill the rear of the reflector and let it harden FIRST. Then I plan on drilling a hole through the new cement. This way I am not trying to deal with holding the lamp inplace and NOT getting cement on the element. Hows that for an idea?? So far the tests with the cheaper metal halide outside the projector are going great it fires right up and stays running. It looks like a super nova. The gap between the electrodes is HUGE on the new lamp. Now I just have to remove the new lamp from it's glass casing and slip it into the newly drilled reflector and fire it up. If I do it right I should be able to slide the new lamp shaft in and out to get it to the sweet spot before the final cementing of it. Feel free to email me @ stuffyhead1@aol.com
Bohanna
Hey Mark,, thanks for the responce . I have been experimenting with a retrofit metal halide in the sanyo projector. I have decides to fill the rear of the reflector and let it harden FIRST. Then I plan on drilling a hole through the new cement. This way I am not trying to deal with holding the lamp inplace and NOT getting cement on the element. Hows that for an idea?? So far the tests with the cheaper metal halide outside the projector are going great it fires right up and stays running. It looks like a super nova. The gap between the electrodes is HUGE on the new lamp. Now I just have to remove the new lamp from it's glass casing and slip it into the newly drilled reflector and fire it up. If I do it right I should be able to slide the new lamp shaft in and out to get it to the sweet spot before the final cementing of it. Feel free to email me @ stuffyhead1@aol.com
Bohanna
guymark said:
cement idea comment
I think that's an excellent idea, and I cannot see why it shouldn't work really well.
The increased electrode gap will be interesting to see how that works.
My very uneducated guess would think that the sweet spot will be much easier - as there will be a range of travel where "as much arc as can fit in the right spot" is present.
The downside (possibly - this is only my humble guess), is that because the arc is so large, no matter how well you align things, some of the arc is NOT going to be at the optimum point / sweetspot - and therefore although REALLY bright now, you may not *quite* get the full output that you were hoping when it is mounted.
Hopefully I am wrong!
Either way, so long as it gets you back up and running, that all seems pretty positive to me 🙂
Kind Regards
Mark
I think that's an excellent idea, and I cannot see why it shouldn't work really well.
The increased electrode gap will be interesting to see how that works.
My very uneducated guess would think that the sweet spot will be much easier - as there will be a range of travel where "as much arc as can fit in the right spot" is present.
The downside (possibly - this is only my humble guess), is that because the arc is so large, no matter how well you align things, some of the arc is NOT going to be at the optimum point / sweetspot - and therefore although REALLY bright now, you may not *quite* get the full output that you were hoping when it is mounted.
Hopefully I am wrong!
Either way, so long as it gets you back up and running, that all seems pretty positive to me 🙂
Kind Regards
Mark
Re: cement idea comment
NO you are right !! DAMMIT!!
The furnace cement worked great. Filling in the rear first letting it harden to a point and than drilling. That idea is the way to go It made it EASY to slide in and out the lamp with NO cement getting on the lamp The trouble is it was about 30% of the Light that was needed. So it is UNUSABLE!! NO matter HOW I adjusted it I couldn't get any More Light. ARGH!!!!!! I also tried putting it in a larger Sanyo 400 watt PLC-9000NA projector I have and the lights fires up great but gets as far as 10 second left on the startup count and shuts down. So I am back to ground zero!!!
Bohanna
guymark said:
NO you are right !! DAMMIT!!
The furnace cement worked great. Filling in the rear first letting it harden to a point and than drilling. That idea is the way to go It made it EASY to slide in and out the lamp with NO cement getting on the lamp The trouble is it was about 30% of the Light that was needed. So it is UNUSABLE!! NO matter HOW I adjusted it I couldn't get any More Light. ARGH!!!!!! I also tried putting it in a larger Sanyo 400 watt PLC-9000NA projector I have and the lights fires up great but gets as far as 10 second left on the startup count and shuts down. So I am back to ground zero!!!
Bohanna
long electrode gap.
Well your cement pre-filling idea worked well - and hopefully someone will make sure your idea of prefilling and then drilling the hole gets to a "sticky" on the board somewhere.
As for your lamp, now you know your cement idea works really well, once you get a new bulb, it should be easy enough to switch them around.
As for the old bulb, if you mount it in a LARGE metal reflector (think massively oversized torches) - then you can have a little searchlight for the house. although definately NOT suggested for normal use, an electromagnetic ballast and starter for a conventional discharge lamp DOES seem to work well - I used a ballast suitable for a mercury discharge light and a the cheapest starter I could buy for a 400w discharge light..
It might de-life the bulb no end, it might be unsafe etc etc etc - but I know if it is dark (and especially if a hint of mist) and I put the 400w discharge light on with the 12" reflector, people can see the beam in the sky from the other side of town quite easily.
Useful? Not really. Fun and silly? Oh yes.
Mark
Well your cement pre-filling idea worked well - and hopefully someone will make sure your idea of prefilling and then drilling the hole gets to a "sticky" on the board somewhere.
As for your lamp, now you know your cement idea works really well, once you get a new bulb, it should be easy enough to switch them around.
As for the old bulb, if you mount it in a LARGE metal reflector (think massively oversized torches) - then you can have a little searchlight for the house. although definately NOT suggested for normal use, an electromagnetic ballast and starter for a conventional discharge lamp DOES seem to work well - I used a ballast suitable for a mercury discharge light and a the cheapest starter I could buy for a 400w discharge light..
It might de-life the bulb no end, it might be unsafe etc etc etc - but I know if it is dark (and especially if a hint of mist) and I put the 400w discharge light on with the 12" reflector, people can see the beam in the sky from the other side of town quite easily.
Useful? Not really. Fun and silly? Oh yes.
Mark
Re: long electrode gap.
Hey Mark,,, I hope SOMETHING that I have done in my never ending quest for the perfect retrolamp is of some use to somebody.
I am however truly surprised that in all the boards I have seen relating to relamping Nobody has suggested this Pre cement method. They all say try to position the lamp BEFORE Cementing and PRAY you get it right and don't get any Cement on the lamp. Hello?? It hit me all of a sudden and I thought duh??. Anyway It would be nice to find the correct element for these UHP/ Metal halide lamped projectors in a cross use type situation
rather than have us all reinventing the wheel. If you hear of a short arc 6500 K 150 to 250 watt Lamp that is available for short money please email me
Many Thanks
BOhanna
guymark said:
Hey Mark,,, I hope SOMETHING that I have done in my never ending quest for the perfect retrolamp is of some use to somebody.
I am however truly surprised that in all the boards I have seen relating to relamping Nobody has suggested this Pre cement method. They all say try to position the lamp BEFORE Cementing and PRAY you get it right and don't get any Cement on the lamp. Hello?? It hit me all of a sudden and I thought duh??. Anyway It would be nice to find the correct element for these UHP/ Metal halide lamped projectors in a cross use type situation
rather than have us all reinventing the wheel. If you hear of a short arc 6500 K 150 to 250 watt Lamp that is available for short money please email me
Many Thanks
BOhanna
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