Sourcing Dichro Mirror Mounts

[Ferrous256]

Hi guys. Noob question here but where can I buy dichro mounts? The only thing I've found so far is:
http://lasershowparts.com/store/inde...&productId=210

I'd like to replace the ones shown in the pictures so I can actually align the beams. A friend dropped these projectors off in terrible condition thinking I can revive them. Looks like they've been through a lot. Been lurking the forums for the past few weeks trying to get an idea of the best way to proceed with repairs. I might be around asking more novice questions as I've never done any laser hardware repair.

[kecked]

Hi guys. Noob question here but where can I buy dichro mounts? The only thing I've found so far is:
http://lasershowparts.com/store/inde...&productId=210

I'd like to replace the ones shown in the pictures so I can actually align the beams. A friend dropped these projectors off in terrible condition thinking I can revive them. Looks like they've been through a lot. Been lurking the forums for the past few weeks trying to get an idea of the best way to proceed with repairs. I might be around asking more novice questions as I've never done any laser hardware repair.

look for mm1 on ebay or flexmount. I prefer mm1. Like 40.00 new off thorlabs

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If it were me I’d start over. That looks awful

[buffo]

Those projectors have had a hard life!

Looks like they didn't have any adjustment on the dichros... Just mounted on a piece of angle-iron, with a single screw to hold it down and a bunch of epoxy to keep it from twisting. Yuck!

I agree with Marc's suggestion: Get some MM1s installed, and alignment will be a snap from now on.

Sources for new:
https://www.thorlabs.com/newgrouppag...tgroup_id=1492
https://www.newport.com/f/m-series-b...-mirror-mounts

Or you can try your luck on Ebay. Typically they sell for ~ $20 on the used market, when you can find them.

Adam

[kecked]

I wish someone made a half size mm1 but never found them. I don’t like flex mounts much. Mm1 can drift but easy to adjust. Usually pretty stable unless you bounce it around.

honestly I’d start over. You can get diodes and drivers soo cheap it’s not worth it. Buy some 506 galvos with dsp drivers and your literally done for life.

so diodes and drivers to do like 1/2 watt is under 100.00. Galvos can be changed later but I think they go for like 1500.00 with drivers and mounts. Likely those dichro suck too.

you can build the whole thing in a 6” box. Well some have done like 3” but that’s showing off.

buy a really cheap unit but one that has a nice case. Toss the guts.

Buffo we should post a step by step diy faq. Would not take much.

[buffo]

Buffo we should post a step by step diy faq. Would not take much.

It's something I've long considered...

Adam

[swamidog]

newport makes mounts for .5" mirrors, but they're not cheap.

https://www.newport.com/g/0.5-inch-mirror-mounts

I wish someone made a half size mm1 but never found them. I don’t like flex mounts much. Mm1 can drift but easy to adjust. Usually pretty stable unless you bounce it around.

honestly I’d start over. You can get diodes and drivers soo cheap it’s not worth it. Buy some 506 galvos with dsp drivers and your literally done for life.

so diodes and drivers to do like 1/2 watt is under 100.00. Galvos can be changed later but I think they go for like 1500.00 with drivers and mounts. Likely those dichro suck too.

you can build the whole thing in a 6” box. Well some have done like 3” but that’s showing off.

buy a really cheap unit but one that has a nice case. Toss the guts.

Buffo we should post a step by step diy faq. Would not take much.

[Ferrous256]

Thanks guys. I found some used 0.5" diameter Newport mounts on eBay for about $25 a piece that should be arriving in the mail today. Hopefully I can make them fit.

Those projectors have had a hard life!

You're right Adam. They are.... not in the best shape, to say the least. Every safety mechanism is broken. Some loose wiring. Some of the drivers aren't even mounted, and the case itself looks like swiss cheese. Seems like someone's been modifying these for a while now.

honestly I’d start over. You can get diodes and drivers soo cheap it’s not worth it. Buy some 506 galvos with dsp drivers and your literally done for life.

so diodes and drivers to do like 1/2 watt is under 100.00. Galvos can be changed later but I think they go for like 1500.00 with drivers and mounts. Likely those dichro suck too.

you can build the whole thing in a 6” box. Well some have done like 3” but that’s showing off.

buy a really cheap unit but one that has a nice case. Toss the guts.

Buffo we should post a step by step diy faq. Would not take much.

A diy faq would certainly help someone like me, but I'm happy to scour the forums. I've found that as soon as I understand my question well enough to articulate it, this forum usually has answers buried somewhere.
You mention the dichros probably suck too. Is there any way to really test that? (aside from making sure they are not scratched and cleaning them free of dust). I suppose dichros, like other manufactured components, have improved quality over time.

If I do a complete rebuild, I'll need to figure out a few more things. I've seen DTR's laser shop for diodes and drivers. And I've seen techhood's ebay store. Any other places I should check out to look for diodes and drivers?

[Ferrous256]

I ended up getting these Newport New Focus 9876 Stainless 1/2" dia. kinematic optic mounts. Not M1 or M2's but I think they'll work really well. They are smaller than I thought they would be. Might be a little less wiggle room for alignment, but seems like a great choice for small form factor boxes.

There's still more than 10 available on ebay. Here's the link:
https://www.ebay.com/itm/23430910661...604%7Ciid%3A14

[buffo]

Wow - $25 for a used, 1/2 inch, 3-axis kinematic mount! I would not have thought they would be available for that price. As they are made from stainless steel, they will basically last forever. Great find!

DTR's site is pretty much the gold standard for purchasing individual diodes and mounts, but you'll have to source your own laser diode drivers and assemble everything yourself. (The drivers that DTR sells are not appropriate for a laser projector; they are designed for hand-held, battery-powered, continuous-duty applications only.) If you decide to assemble your own modules with parts from DTR, you might want to consider adding Lasorbs from Pangolin to each diode to protect it from static shocks and transient over-voltage spikes. (Make sure to buy the correct Lasorb for the specific diode you're trying to protect.)

On the other hand, if you want to buy whole laser modules that are ready to be installed in the projector, your best bet is probably one of the Chinese suppliers. (Goldenstar, OptLaser, etc.) Most of what they sell are all-in-one RGB modules (so you don't need any dichros or mounts, because all of that is internal to the module) but if you dig around you can find individual modules for Red, Green, and Blue.

Marc suggested the ScannerMax Compact 506 galvos from Pangolin, and while I agree that they are amazing, they come with a price tag to match. If those scanners break your budget, you might want to consider either DT-40 or PT-40 scanners, both of which run about $250 per set from the same Chinese suppliers above.

Connecting these components together (and to the ILDA port on the back of the projector) is largely an exercise in following directions. "Red + signal on ILDA pin #5 connects to positive modulation input on red diode driver; X + signal on ILDA pin 1 connects to X + input on scanner amp", and so on... This diagram of the ILDA pinout should help. Also, this article about power connections and grounding is super helpful.

Testing the dichros is going to be very difficult unless you have a power meter. You can set the dichro at a 45 degree angle and try to judge how much power is leaking through, but with nothing to compare the leakage to, your results will be inconsistent.

Regarding the idea of just replacing your dichros - in the past I would recommend that people purchase replacement dichros from Thorlabs, Edmund's Optics, or Newport. However, in the post-Covid market, prices at those suppliers have gone up by a factor of 4 or more. So a dichro that used to cost $50 is now selling for $215. (Ouch)

Once again, you could turn to one of the Chinese vendors listed above, but if I were you I would first see how the projector performs with the existing dichro set. It's fairly easy to swap out the dichros later on, if that becomes necessary.

Be mindful of your beam alignment. Your near-field alignment is how close the beam dots overlap at the dichro face. This can be adjusted by moving or shimming the diode module, and/or by translating the dichro along the main beam path. You need to have the dots from each beam overlapping perfectly at the reflective face of each dichro. Your far-field alignment is how close the beams overlap on the wall some distance from the projector. This is adjusted by the X and Y adjustment screws on the dichro itself.

Note, however, that if your near field alignment isn't perfect, your far field alignment will change based on the distance from the projector to the wall. If you can't seem to get your far-field alignment dialed in so it's perfect at both ~ 8 feet and ~ 35 feet from the projector, it means that your near field alignment is off. Proper planning regarding the mounting position of your diode modules will help ensure your near-field alignment is close to start with. Then, with a little adjustment of the dichro position and some slight adjustment of the module, you should be good to go.

Alternately, if you introduce a second bounce into the beam path of each laser color, you can give yourself full adjustment of both near and far field alignment using kinematic mounts. This arrangement costs more, and you lose a bit more power from the extra mirror bounce, but it's a foolproof method for perfect alignment. Here's an image that explains what I mean. It assumes that the beam from the green laser is perfectly aimed at the scanner mirrors to start with. The MM1 on the first mirror adjusts where each beam lands on the dichro face (thus, the near-field alignment), while the MM1 on the dichro adjusts the final beam position (thus, far-field alignment). Not sure if you have room for such an arrangement in your projector case, but it's an option.

Adam

[Ferrous256]

Thanks for the detailed answers, as always Adam. It really helps a lot!~