70% Power Loss Through Scanner Mirrors....

[Insanity]

I'm losing loads off my laserworld mirrors in two projectors, about 250mw out of a watt of green...

They are .6mm thickness according to the laserworld manual... I am going to replace them with some I bought from Dave (Lasershow Parts)... The replacements are .7mm, but my guess is that knowing laserworld, the tolerance on the shafts is probably somethind like +/- 1" If they are tight, I will carefully file the groove with a half round needle file...

To summarise, Laserworld mirrors are crap, but we should have guessed that really Therefore if you buy a laser from them, it's underpowered to start with and then the optics and mirrors loosing power as well, probably be better off with a pointer and a bit of tin foil

Mark

[gottaluvlasers]

i dont think LW uses broadband coatings for their mirrors on the scanners. this would explain 95% of your problem. ESPECIALLY with lower wavelengths like 473.

measure the loss of a 532 off of your scanner mirrors. i bet its about 2%-10% max. meaning that the mirrors have a very narrow "sweet spot" band of reflectivity. probably about 500-600nm TOPS.

LSP scanner mirrors and daves (DZ's) mirrors have broadband coatings. you will notice prob no more than about 2% - 5% loss on each bounce! from ~400nm- >700nm!!

-Marc

[300EVIL]

Good News!!!

I replaced the original galvo mirrors for the spares that came with the scanner kit after determining the coatings are different. The old mirrors had a green coating on them where as the new mirrors have a violet tint to them. Now I'm getting a little over 200mW of 473! I'm very happy now! Gonna go and retune my scanners and have a light show in celebration.

[allthatwhichis]

And post some pictures!!! I am half way through a new show myself. When is your next show due out?

[300EVIL]

And post some pictures!!! I am half way through a new show myself. When is your next show due out?

Sweet! Well, if it's as good as your last one, I want a copy! I'll get around to doing another show as soon as I sort out a few other issues. I'm not far off though.

Here are a couple pics that turned out, somewhat. I'll break out the tripod and take some better ones tomorrow.

[cruch]

DZ:
regarding the replacement mirrors for the DT40 Pro, what size do you have?

[zerowaitstate]

Care to elaborate on the process of swapping out the mirrors, I also have the (50K not scanners) from laser world and decided against swapping them as it looked to be hard to get them lined up dead straight and ballanced precisly.
Also are you now able to get better scan speeds from the units not that you have the smaller mirrors ?

[300EVIL]

Care to elaborate on the process of swapping out the mirrors, I also have the (50K not scanners) from laser world and decided against swapping them as it looked to be hard to get them lined up dead straight and ballanced precisly.
Also are you now able to get better scan speeds from the units not that you have the smaller mirrors ?

Yeah, I read they were supposed to be smaller and/or thinner mirrors, but they are not. They actually look cheaper but without some lousy coating that kills blue.

Swapping was really easy. I just heated the epoxy with a fine tip soldering iron while applying slight side pressure to the mirror. The epoxy gives way in about 15 seconds and you can carefully scrape the remaining glue off the shaft with a dental tool.

I was going to build some crazy jig for holding the new mirrors centered but I just eyeballed it and they stuck square and true. I used a tiny dab of thoroughly mixed 5 minute epoxy on the tip of the shaft. Don't let the mirror slide down! The groove is deeper than the end of the armature and will touch. Just leave 0.5 - 1mm between the armature and the mirror. From there I just held the mirror in place until the glue started to thicken. You can do a little tweaking here and there while it's hardening to make sure it's streight.

Probably not the best procedure but it worked for me!

PS: You will have to re-tune your scanners as well.