well it makes life alot easier as i dont have to worry about laser height to get all three beams to hit the dichro at the same point
Senior Member
well it makes life alot easier as i dont have to worry about laser height to get all three beams to hit the dichro at the same point
Eat Sleep Lase Repeat
Senior Member
Yeah why not put yopur lasers where each of the mirrrors are...More optics you have more power you loose! Keep it as simple as possible!
Senior Member
As Andy said (several times already) he is doing this for the ease of alignment. You can find images of projectors that have a similar design implemented with great results.
Granted, yes, you will lose more output due to optical loss... but as with most hobbies, this one is all about trade-offs. Clearly Andy doesn't want to futz around with metal shims to make the laser apertures all at the same height.
Yes, most of us want to penny-pinch every mw out of the system as possible. But Andy wants to reduce alignment time. I guess time is more valuable to him... and well it is to me too, but I have my own opinions...
Good luck Andy, I look forward to seeing some real images... no more of this CG stuff OK?!
If he uses *good* mirrors, he won't loose more than a few mw of power. It's a good trade-off for the ease in alignment.
With two bounces, you don't need to have *ANY* adjustment for your lasers. No worries about beam height and no worries about whether the beam is parallel to the baseplate. All that can be compensated for with the two bounces. The first mirror adjusts your near-field alignment, and the dichro adjusts your far-field alignment.
It's a very nice arrangement that avoids all the hassle of custom shims, floating tables, and all the other nonsense. The lasers are hard-mounted directly to the base plate. Alignment takes a couple minutes, tops.
Of course, if you don't buy really good mirrors, you will loose a little power, but it's not nearly as bad as one might think. It's easy to find broadband mirrors that are 98% reflective (or better). So what's the big deal about loosing 2%? (Especially when you're probably loosing 10% across your scanners!) You want to increase your efficiency? Start with your scanner mirrors...
Adam
Edit: Max, you beat me by 9 minutes!
Last edited by buffo; 01-03-2008 at 06:48.
Senior Member
I see, makes sense now.
THIS USER WAS CLUEBYFOURED
Pros - easily to align, no custom fab work needed, allows swapping out of parts if needed.
Cons - more space required, more losses, higher chance of things breaking or coming out of alignment.
Based on Andy's knack for destroying lasers I think he made the right choice.
(Just kidding with you Andy.)
OUCH!Originally Posted by carmangary
Based on Andy's knack for destroying lasers I think he made the right choice.
(Just kidding with you Andy.)
Seriously though, I've been thinking about this sort of layout for some time, and I gotta admit that it makes a hell of a lot of sense. The main trade-off in my mind is the increased size of the projector. But beyond that, it's really smart.
I just installed my replacement Lasever DPSS blue in my projector, and of course it was different from the other one I had, so I had to re-align everything. I got a little worried, because I had to lower the table for the blue laser really low to get it aligned. If I had run out of adjustment room on the blue table, I would have been forced to raise all the other tables, and that would have *really* sucked...
During the whole time I was thinking to myself, "You know, if I only had another bounce mirror in the path, this alignment would have been a cinch!" So maybe when I re-design the projector again I'll look into such a layout. (No way it will work with the smaller projector case I have now, but maybe if I get a new case...)
Adam
Senior Member
thanks mate.As Andy said (several times already) he is doing this for the ease of alignment. You can find images of projectors that have a similar design implemented with great results.
Granted, yes, you will lose more output due to optical loss... but as with most hobbies, this one is all about trade-offs. Clearly Andy doesn't want to futz around with metal shims to make the laser apertures all at the same height.
Yes, most of us want to penny-pinch every mw out of the system as possible. But Andy wants to reduce alignment time. I guess time is more valuable to him... and well it is to me too, but I have my own opinions...
Good luck Andy, I look forward to seeing some real images... no more of this CG stuff OK?!
its not time vs mw, its just ive done adjusting module heights before and its a real pain in the ass.
these are the mirrors i haveIf he uses *good* mirrors, he won't loose more than a few mw of power. It's a good trade-off for the ease in alignment.
With two bounces, you don't need to have *ANY* adjustment for your lasers. No worries about beam height and no worries about whether the beam is parallel to the baseplate. All that can be compensated for with the two bounces. The first mirror adjusts your near-field alignment, and the dichro adjusts your far-field alignment.
It's a very nice arrangement that avoids all the hassle of custom shims, floating tables, and all the other nonsense. The lasers are hard-mounted directly to the base plate. Alignment takes a couple minutes, tops.
Of course, if you don't buy really good mirrors, you will loose a little power, but it's not nearly as bad as one might think. It's easy to find broadband mirrors that are 98% reflective (or better). So what's the big deal about loosing 2%? (Especially when you're probably loosing 10% across your scanners!) You want to increase your efficiency? Start with your scanner mirrors...
Adam
Edit: Max, you beat me by 9 minutes!
http://cgi.ebay.co.uk/ws/eBayISAPI.d...MEWN:IT&ih=001
no your spot on, i do seem to get through lot of lasers. the thing that annoys me is i took so much time and effort with my lasever green not to do anything wrong. i connect the blanking wires and it fooks up LOLPros - easily to align, no custom fab work needed, allows swapping out of parts if needed.
Cons - more space required, more losses, higher chance of things breaking or coming out of alignment.
Based on Andy's knack for destroying lasers I think he made the right choice.
(Just kidding with you Andy.)
im doomed with lasers.
i only takes up a little bit more space, with ym two levels it does not really make and odds
Eat Sleep Lase Repeat
You might want to shop around a bit there, Andy. You can get better mirrors than that for not much more money. Here's some that are 97% reflective. (They're 5 for 10 bucks, or just $1 more each than the one's you linked to in that E-bay auction.)
Then too, someone posted a link to a surplus electronics dealer a while back that was closing out some very high efficiency broad-band mirrors for 12 bucks a pop. I bought 4 of them, but I can't remember the name of the surplus dealer! Did a quick search but came up empty. Anyone else remember that company? They had plenty of those mirrors, and they'd be perfect for a projector layout like Andy is proposing...
Adam
THIS USER WAS CLUEBYFOURED
I think i posted that. it was All Electronics I believe.
http://www.allelectronics.com/cgi-bi...E_MIRROR_.html
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