RGB Laser System in acrylic box

[blrock]

6x10mm galvo mirrors arrived today. Hope to install them this weekend and take a video.

Anyone ever changed galvo mirrors? The current mirrors almost look like they have been soldered onto the shaft. This will no doubt be delicate work. I can only think of using epoxy glue afer removing the old ones. Would hate to damge the new mirrors. They were rather expensive to import from Germany!

 

[Benm]

Getting the old ones out without damaging the galvo's is probably the most difficult part - the ones i have are potted in place with something that looks like epoxy. I'm not really sure how to go about removal - doing so by force could damage the galvo arm. Perhaps its possible to dissovle/weaken the epoxy by some solvent, but that depends on what the galvo arms are made off too.

 

[andy_con]

to get the old ones off use a soldering iron the heat the glue.

when putting new ones on dont use to much glue also dont use to little. make sure the mirrors are straight all round.

i normally use two part epoxy

 

[blrock]

Before removing the mirrors I took some new readings:
Green 1117mW
Red 490mw
Blue 910mw
TOTAL: 2517 mW

The galvo mirror replacement went well, then disastrous, then well, this weekend. Soaked the ends in acetone for several minutes then used a springhook to pull the mirror.
First mirror came off rather easily. The second mirror broke! Then broke again until there was a tiny piece of mirror stuck in the shaft of the galvo. I had to use tremendous force from a pin and sharp thin knife to literally crush the mirror piece by piece. I thought the galvo would never work again due to a bent shaft!

After glueing the new mirrors the end result was fantastic. Both galvos worked perfectly. I can confidently say that the galvos are a little tougher than we believe! (or maybe because they were made in Germany and not China )

The output power was what really make all worth while:
Green: 1210 mW
Red/Blue 2473 mW
Total: 3681 mW

Gained over a watt extra! I'm still tempted to change my dichros as I still have significant loses. Actual collective power of all the lasers is 4800 mW!

I captured two videos sync'd to some music. Will upload them soon!

 

[Helios]

Im surprised they use such crap mirrors on what sounds like some good galvos. Whats the price difference between a cheap mirror and a decent one?! As far as I know not a whole lot.

 

[blrock]

Im surprised they use such crap mirrors on what sounds like some good galvos. Whats the price difference between a cheap mirror and a decent one?! As far as I know not a whole lot.

Crap mirrors? Why would you say that? The only reason I changed them was because the standard mirrors were 5x11x0.6mm. I needed the larger 6x11x0.6mm to compensate the larger red and blue beam. Thats why 1 watt was "lost"

Anyways herewith two videos:

Day test:
YouTube - ‪Home built RGB Laser 3.6 watt‬‏

Night test with 3 bounce mirrors and one diffraction
YouTube - ‪Home built RGB Laser 3.6 watt Night‬‏

 

[Helios]

Crap mirrors? Why would you say that? The only reason I changed them was because the standard mirrors were 5x11x0.6mm. I needed the larger 6x11x0.6mm to compensate the larger red and blue beam. Thats why 1 watt was "lost"

Oh okay that makes more sense

 

[Benm]

Sounds like a very good result indeed - and they dont seem to be -that- much bigger than the ones that came with the system either, so perhaps the performance penalty will not be that great.

The problem with mirrors is that you need them to be bigger than the beam diamter - you'll hit them at 45 degrees typically, so if your laser beam is 5mm diameter you'd already need a 7mm mirror to bounce the entire beam off of.

For most dpss systems meeting that beam diameter is no problem, but with direct diodes for red and blue you can find yourself in trouble fairly quickly.

 

[blrock]

Sounds like a very good result indeed - and they dont seem to be -that- much bigger than the ones that came with the system either, so perhaps the performance penalty will not be that great.

The problem with mirrors is that you need them to be bigger than the beam diamter - you'll hit them at 45 degrees typically, so if your laser beam is 5mm diameter you'd already need a 7mm mirror to bounce the entire beam off of.

For most dpss systems meeting that beam diameter is no problem, but with direct diodes for red and blue you can find yourself in trouble fairly quickly.

Thanks for that. Now that I think of it you right. I have rather small dichros and @ 45 degrees some of the red is already "missing" the dichro.
Maybe I should try a piece of dichro from the A140 c@sio projector?

 

[CDHDC]

I Love it! It's sure is purdy

 

[Benm]

I don't know about the dichro from the projector.. must most dichros arent that small to begin with, half an inch to one inch diameter seems faily common. I'm not sure about their quality, but these are very cheap: RGB laser systerm combine optical lens /2pcs in a pack [OLRGML] - $25.00 : Welcome to O-Like.com, Your source for laser products

You would want dichros so be significantly bigger than any beam diameter so you have some room to manouver them around when adjusting the beams onto eachother. If you move a dichro away from a laser the point of impact also changes, and its a lot easier if you have a few exta milimeters there.