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Thread: First time building laser

  1. #1
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    Default First time building laser

    Hi there,

    I am interested in building a laser, using the housing of a laser I currently own. It's a V-show Pro L0303 which measures 29x17x22cm. I'm aiming for the power output to be >= 3W, and for an FB4 to be installed. I have a few questions regarding this project.

    1. How feasible is it for me to be able to build the laser to the specifications I have listed in the enclosure I am using?
    2. What are the best resources for someone like me, who has close to 0 technical knowledge on the design and construction of lasers to set about doing this?

    I have experience with laser show control and programming and laser safety, however, I wish to expand my knowledge to a more technical side of things, which is why I am embarking on this project. I've had a look through Sam's FAQ but it's been a bit hard finding all the right pieces of information. If anyone could point me in the right direction that would be greatly appreciated!

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    Welcome to PhotonLexicon!

    The case you mentioned is a bit on the small side, so things will be a little cramped, but it's plenty big enough for what you want to do. You'll just need to spend a bit more time planning everything out before you start drilling holes.

    Most people start out with a larger case for their first build so they have lots of extra room, but with careful planning it's possible to build a 3 watt RGB projector into a very tiny package. (Consider the LaserCube from Wicked Lasers, which is 2.5 watts in a cube about 11 cm on a side, and that includes a battery that will run the thing for about 3 hours!) So your case is certainly large enough for what you want to accomplish.

    It sounds like you would prefer to do as much of the assembly yourself, rather than purchasing pre-assembled off-the-shelf components and just connecting them together. Thus, I'm assuming that you don't want to simply purchase an all-in-one RGB module and drop that into the case along with a set of scanners, even though this would be the easiest way to achieve your goal. (It's probably cheaper as well, at least for a projector with basic beam quality and standard 30K scanners.)

    If, instead, you're thinking about purchasing individual laser modules (or even buying the diodes, the diode mounts, the optics, and the drivers separately, and then assembling everything yourself), plus a set of dichros and some kinematic mounts, plus a set of scanners, and then building all of that together into a working projector, (hopefully with at least a rudimentary safety interlock and E-stop system) then this forum is probably going to be your best resource. Unfortunately, the forum search engine isn't very good. Using Google with the "site:PhotonLexicon.com" modifier may help, but you're still going to end up paging through lots of individual threads if you want to soak up some of the institutional knowledge stored here.

    The good news is that most of the senior members here do not mind answering questions, even if the topic has been covered before. So once you start planning your build, please feel free to ask questions here. Also, be prepared to post pictures of your build as you progress. This will make it easier for others to offer advice, but it might also inspire new members to undertake their own builds, and that's always a plus. (Building a projector from scratch is an excellent way to learn!)

    You said you have experience with show programming and laser safety. That's a great start. You'll also need to learn just a little bit about basic electricity if you haven't done so already. If you literally have zero experience with electricity, then I suggest you first read Forrest M. Mims book, "Getting Started in Electronics". You can find scanned .pdf copies of this on-line, but the book only costs about $20 from Amazon (spiral bound version), and you will probably want to have a hard copy available that you can scribble notes on as you read.

    The book is not very large (~ 125 pages or so), and honestly, you only need to read about the first 1/3 of the book; once he starts getting into transistor theory, you can stop. You don't *need* to understand how transistors work to build a laser projector. Admittedly, it's useful information though, and if you can wrap your head around simple op-amp circuits, that is even better, but worst case, you can treat these devices as "black boxes" and just understand that when you hook them up a certain way, you get the desired result.

    The later portions of the book delve into digital circuits, and the appendix has lots of example circuits. Most of this material will not be useful for your project, although it's a great reference if you decide to try building other electronics projects from scratch.

    The other skills you'll need are basic soldering, and basic metal working (hand tools only). If you can drill a hole in an aluminum plate and attach components using nuts and bolts, that's good enough. Even better if you can learn how to use a tap to cut threads in the holes you'll need to drill, but if you don't want to mess around with tapping threads you can always through-bolt everything to the baseplate and secure the bolts in place with nuts on the underside. (Better to use nylon locknuts so they can't work loose!)

    You'll need a basic soldering iron. Not a soldering gun, but an iron. Figure on paying $15-$20 for it, although if you don't mind splurging, I'd suggest a cheap soldering station that includes the iron, a spring holder, a sponge (to help clean the tip) and a temperature adjustment. These mini soldering stations usually cost around $30-$40 on Amazon; they're rated for between 25 and 40 watts, and they are much easier to use than a cheap 25 watt iron.

    Then you need to decide how much money you want to spend on this project. For example, what sort of scanners do you want to use? Cheap, 30K scanners from China can be had for less than $300, but if you want to go with something like the ScannerMax Compact 506 scanners from Pangolin, you'll be spending 4 times that amount, and if you're thinking about 60K performance, well, then we're taking REAL money. Then too, what sort of beam specs are you prepared to live with? If the projector will be used primarily for beam shows, you might not be overly concerned about beam diameter, profile, or divergence. But if this will be used for graphics or abstracts, then the beam quality is more important. Secondary correction optics can get expensive, you see...

    So give some thought to all of the above, and when you're ready, reply back here and tell us more about what you want to get out of this projector, how much you want to spend, what you feel comfortable doing, and how far you want to go with the whole "I built everything myself" idea. Also include any other topics that you feel you want/need to learn more about as you work on this project. Then we can start talking about where to go looking for parts.

    Adam

  3. #3
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    Hi Adam,

    Thanks for the in-depth reply.

    The case you mentioned is a bit on the small side, so things will be a little cramped, but it's plenty big enough for what you want to do. You'll just need to spend a bit more time planning everything out before you start drilling holes.
    This is a fair point. I was thinking of building it in an enclosure I already have in order to cut costs, but now that I think about it, I'd probably save more money just by selling the laser

    It sounds like you would prefer to do as much of the assembly yourself, rather than purchasing pre-assembled off-the-shelf components and just connecting them together. Thus, I'm assuming that you don't want to simply purchase an all-in-one RGB module and drop that into the case along with a set of scanners, even though this would be the easiest way to achieve your goal. (It's probably cheaper as well, at least for a projector with basic beam quality and standard 30K scanners.)

    If, instead, you're thinking about purchasing individual laser modules (or even buying the diodes, the diode mounts, the optics, and the drivers separately, and then assembling everything yourself), plus a set of dichros and some kinematic mounts, plus a set of scanners, and then building all of that together into a working projector, (hopefully with at least a rudimentary safety interlock and E-stop system) then this forum is probably going to be your best resource. Unfortunately, the forum search engine isn't very good. Using Google with the "site:PhotonLexicon.com" modifier may help, but you're still going to end up paging through lots of individual threads if you want to soak up some of the institutional knowledge stored here.
    I definitely want to get as hands on as possible, however I don't have a massive assortment of tools. From what I understand, it's extremely important to get everything aligned juuuuust right, and I'm unsure how easy/difficult that is with my current situation. To give a bit of context as to why I'm deciding to embark on this project, I only started playing around with lasers around 4 months ago, mostly making timeline shows. I recently was talking to somebody who discussed what would have been a life changing opportunity for me, however, it fell through as I did not have enough technical experience for them to be confident in me. I want to make sure that the same thing doesn't happen again, and that I can proudly demonstrate some technical knowledge to them in the future.

    You said you have experience with show programming and laser safety. That's a great start. You'll also need to learn just a little bit about basic electricity if you haven't done so already. If you literally have zero experience with electricity, then I suggest you first read Forrest M. Mims book, "Getting Started in Electronics". You can find scanned .pdf copies of this on-line, but the book only costs about $20 from Amazon (spiral bound version), and you will probably want to have a hard copy available that you can scribble notes on as you read.
    I have a very basic understanding of electricity (Ohm's law and a few other tidbits are the only things that come to mind) so I'll be sure to brush up on that.

    The other skills you'll need are basic soldering, and basic metal working (hand tools only). If you can drill a hole in an aluminum plate and attach components using nuts and bolts, that's good enough. Even better if you can learn how to use a tap to cut threads in the holes you'll need to drill, but if you don't want to mess around with tapping threads you can always through-bolt everything to the baseplate and secure the bolts in place with nuts on the underside. (Better to use nylon locknuts so they can't work loose!)

    You'll need a basic soldering iron. Not a soldering gun, but an iron. Figure on paying $15-$20 for it, although if you don't mind splurging, I'd suggest a cheap soldering station that includes the iron, a spring holder, a sponge (to help clean the tip) and a temperature adjustment. These mini soldering stations usually cost around $30-$40 on Amazon; they're rated for between 25 and 40 watts, and they are much easier to use than a cheap 25 watt iron.
    I'm pretty shoddy with metal working but that doesn't seem too difficult for me. I'll just have to see whether I've got the right tools, but I'm sure they're lying around somewhere / can borrow some from a friend. I actually have an old Weller soldering station that I haven't used in a few years, so I'll be sure to dig that out.

    Then you need to decide how much money you want to spend on this project. For example, what sort of scanners do you want to use? Cheap, 30K scanners from China can be had for less than $300, but if you want to go with something like the ScannerMax Compact 506 scanners from Pangolin, you'll be spending 4 times that amount, and if you're thinking about 60K performance, well, then we're taking REAL money. Then too, what sort of beam specs are you prepared to live with? If the projector will be used primarily for beam shows, you might not be overly concerned about beam diameter, profile, or divergence. But if this will be used for graphics or abstracts, then the beam quality is more important. Secondary correction optics can get expensive, you see...
    I'm really not sure myself. I know that I'll already spending a fairly pretty penny on an FB4, and I also do want this to be of higher spec than the two lasers I currently own (the aforementioned V-show laser and a Unity Raw 3). A 40k scanner would be super nice to have but 30k from my experience is still a solid speed for most beam show applications. As for the beam specs, I'm not overly concerned on the beam diameter and such, however, one thing that I definitely want to be strict on is the colour performance. The colour output of my two lasers makes it hard to tune them properly, as each colour will only turn on above a certain brightness, and the colours themselves aren't balanced in terms of brightness. Both my lasers suffer from the infamous Mountain Dew Green hue when trying to display yellows and it's hard to distinguish between blue and purple most of the time. I'm not too sure which components exactly are the ones that dictate colour performance but whatever they are, I want to make sure they are top of the line.

    I guess an overall budget, I would place no higher than $3k. I'm a student with no real stable income at the moment as I've lost work due to COVID lockdowns, but I can raise a bit of capital through selling some of my belongings. It's a small price to pay for some valuable education, and hopefully a really nice laser at the end of it.

  4. #4
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    Quote Originally Posted by pewtifal View Post
    I definitely want to get as hands on as possible, however I don't have a massive assortment of tools.
    Regarding tools, beyond the soldering station we already discussed, you'll only need a few others. For sure you'll need a digital multi-meter and a hand-held drill, along with an assortment of drill bits. An electric jigsaw might also come in handy, in case you need to cut the baseplate, but in a pinch you could make do with a hacksaw. (And it's likely that you won't need to cut the baseplate at all.) A dremel tool is also very useful if you need to cut the sheet metal of the case to install connectors, etc. And of course, you'll want a basic set of screwdrivers, allen wrenches, and an adjustable wrench or two. That should be everything you'll need though.

    From what I understand, it's extremely important to get everything aligned juuuuust right, and I'm unsure how easy/difficult that is with my current situation.
    Yes, but there are two ways to achieve that alignment: You can precisely fabricate each component to exacting tolerances and then mount those components with extreme precision so everything lines up perfectly, or you can do what everyone else does, which is to simply mount all the components rigidly (so they can't move) and then place all of your optics on adjustable kinematic mounts and use the adjustment screws on the mounts to tweak the beam alignment so it's perfect.

    I recently was talking to somebody who discussed what would have been a life changing opportunity for me, however, it fell through as I did not have enough technical experience for them to be confident in me.
    It sounds like they were looking for someone with more experience. Did they say if they were willing to reconsider you for this opportunity at some point in the future? Or have they already moved on and selected another candidate?

    Regardless, building a projector won't make you an expert, but it will teach you a lot about how a projector functions, and it will also teach you the basics of how to troubleshoot a projector that isn't working correctly. Whether this is enough for them to reconsider you as a candidate is unknown, but I think you'll find that the project will be quite rewarding no matter what.

    I have a very basic understanding of electricity (Ohm's law and a few other tidbits are the only things that come to mind) so I'll be sure to brush up on that.
    Sounds like you're most of the way there, then. Forrest Mimms' book is still a great reference to have on your desk, but yeah, a basic understanding of Ohm's Law and series vs parallel circuits is probably sufficient to complete the build.

    I'm pretty shoddy with metal working
    Starting with a pre-made case should limit the amount of metal working needed to complete the build. It's very likely that you'll just need to drill some holes in the aluminum baseplate to mount the components. Worst case, if you do have to make some large cuts in the baseplate (either using a jigsaw or a hacksaw), you can always clean up the edges with a file and some sandpaper later.

    I actually have an old Weller soldering station that I haven't used in a few years, so I'll be sure to dig that out.
    Excellent! That will be perfect for this project.

    I'm not overly concerned on the beam diameter and such, however, one thing that I definitely want to be strict on is the colour performance.
    Color performance is mostly related to the laser diode driver that you select. Obviously you'll want a driver that supports analog modulation, but some drivers are better than others when it comes to this. The other major factor affecting color performance is the color balance settings in the software you're using. You mentioned that you are planning to purchase an FB4, which means you'll be using either Quickshow or Beyond. Both programs will allow you to make fine adjustments to the color balance, so with a good driver you should be OK.

    I guess an overall budget, I would place no higher than $3k.
    That is more than enough to build a very nice 3 watt RGB projector, including the cost of the FB4 controller. In fact, you might be able to build a pair of them for this budget if you are careful and shop around.

    Here's an off-the-cuff estimate to give you some idea of what you are in for:

    Looking at DTR's Laser Shop, and using conservative numbers for a color-balanced ~ 3 Watt RGB projector (say, 750 mw of 638 nm red, 1 watt of 520 nm green, and 1.5 watts of 445 nm blue), you can purchase all three diodes in 1 inch copper heat sink modules with the primary collimating lenses already installed for less than $300 total.

    To that, you'll need mounts to attach the modules to the baseplate, drivers for each diode, dichros to combine the red, green, and blue beams, and kinematic mounts to handle the fine adjustment. Figure $120 for the drivers (~ $40 each), $150 for the mounts ($~ 50 each), $150 for the two dichros and one bounce mirror you'll need, and $300 for the kinematic mounts. (Bear in mind that this is a worst-case analysis that assumes you buy everything at full retail price. You can easily do much better than these prices. Ebay is your friend!)

    So at this point you're up to just over 1 grand for the lasers and optics. A set of 40K scanners can be had for $300. Then you'll need a decent power supply to supply the diode drivers (the scanner set will come with it's own power supply), so figure another $50 there, and we'll toss in another $100 in "incidentals" to cover things like ILDA connectors, power connectors, and so on. That's still only $1450, and as I said, this number includes a LOT of fat. In all likelihood, you'll end up spending around a grand, if not a bit less, for everything listed above. Even if you double that for 2 projectors, you'll still have enough left over for the FB4.

    On the other hand, if you wanted to go down the easy road, you could buy the scanners listed above and just pair them with an all-in-one RGB module for around $400, plus another $50-$100 in incidentals and be done for less than $800 total. However, this won't teach you very much about the inner workings of a laser projector, nor will it be something you can easily work on if it ever fails. (Plus the beam quality on that module isn't very good, and I doubt you'll be pleased with the color performance either.)

    Adam

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    Hi Adam,

    Thanks for the reply, I really appreciate the level of detail in your posts.

    I'm going through the sites that you have linked but I'm still not sure how one would know which parts to select. I'm assuming it would be best to have some level of CAD knowledge, so one could plan out the space requirements for all the parts. But in terms of, for example, the diodes, I have no clue what separates one diode from another (What's the difference between the 12mm and 20mm module, or what's the difference between the different glass lenses for example), and this extends to pretty much all the parts involved (apart from the scanners). Where would I be able to find resources to help me learn about these components?

    Victor

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    hey man, most of the info ur looking for is just had by reasesrch on this forum, i think some people have made up a parts list from their builds. check out my post "i finialy finished my rgb projector" i think its called and i listed some of the components i used.

    asfar as ur question about the diode mounts the 20mm vs 12 is the size of the heatsink the laser is mounted in. i used 20 mm copper heatsinks from dtr and pressed my own diodes in them. he sells presses for them. u have to solder them ur self and that saves some cost and gives u the freedom to use the length of wire needed to ur driver. but u may want to do some soldering exersizes befor working on expensive diodes. the copper heatsinks can be mounted in aluminum mounts, i found some on ebay.

    it took me a long time to get everything togeather and there were some ups and downs. i killed a 100$ diode in the process. made alot of mistakes drilling and tapping. learned alot.

    make a basic plan of how you want the setup. and get ur diode heatsinks, powersupplys and scanner and dichro mounts and drivers. set everything up to makesure the size of ur project box is good.

    i used a fb3 instead of fb4 bc i would be able to use it on a diffrent projector downthe road with out having to remove the fb4 from my first project. 25ft ilda cable is cheap. and i didnt need to do a long run bc this was just a personal hobby project and not something i was going to use in a show enviroment.

    make a good plan. make a parts list, start chipping away at getting parts. u might need a multimeter, a test load for the lasers to set driver current and maybe a benchtop powersupply to set ur drivers up and u can test ur diodes and play around waiting for more parts.

    have fun with it! ull learn alot. and remember, ur work becomes a little shotty after a 6 pack haha.

    cheers
    matt

  7. #7
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    Quote Originally Posted by pewtifal View Post
    I'm still not sure how one would know which parts to select.
    No worries, Victor. If you have questions, just ask. That being said, the diodes linked in my post above would be a good start for a ~ 3 watt RGB build.

    I'm assuming it would be best to have some level of CAD knowledge, so one could plan out the space requirements for all the parts.
    Eh... You could use CAD, but that's probably overkill. A sheet of graph paper and a ruler is probably good enough for planning purposes.

    I have no clue what separates one diode from another
    That comes with experience, but for now you can get a good idea by just looking at other people's projects. Read through the build descriptions and pay attention to the diodes that they selected and the reasoning behind each decision. And again, if you don't understand something, just ask.

    As Matt explained, the 12mm vs 20 mm vs 25 mm sizes on DTR's website refer to the diameter of the round copper or aluminum diode mounting block that the diode is inserted into. In general, you want to use larger blocks for higher power diodes, unless you're planning on an active cooling solution using a thermo-electric (Peltier) cooler. (In those cases, it's often better to have a small block that is close to the same size as the TEC element.) Also, TEC builds usually use a diode block that is square or rectangular, rather than round. I don't think you'll need such an aggressive cooling solution for your projector, however.

    Note that the diodes themselves also come in various sizes: 3.8 mm, 5.6 mm, and 9 mm are the most common. The diode mounting block that you select needs to have the same size hole as the diode you plan to use. And yes, there are lots of places to purchase diode mounting blocks (in all sorts of shapes and sizes), but DTR's site is convenient in that you can get everything you need (diode, mounting block, lens holder, and collimating lens) in one place and be certain that it will all fit together properly.

    The different lenses you see on DTR's site are all designed to collimate the raw output from the laser diode to a nice, tight beam. However, there are trade-offs. The lens that gives you the lowest divergence (and thus the tightest beam at a distance) might also reduce your available output power by as much as 30%. Then too, the performance of a given lens will change depending on what type of diode it's used with. Some lenses that work exceptionally well on a 445 nm blue diode in a 9 mm can might only yield average performance on a 520 nm green diode in a 3.8 mm can. Cost is also a factor...

    To select the best lens, you have to read through the test results for each one, which can get a little tedious. DTR's site has links to a few threads where Jordan has tested various lenses on some of the more popular laser diodes. There are also threads here on PhotonLexicon that discuss the pros and cons of various lenses. Admittedly, this information isn't all that easy to find, but with a bit of digging you should be able to uncover the details you're looking for.

    Just remember that there is no "one size fits all" solution. Sometimes the G3 lens will be your best option. Sometimes it will be the G8. And at times, the best lens might be one of the multi-element options. (Here's a link to a page on DTR's site that shows a few examples of this.)

    Quote Originally Posted by prosnurfer View Post
    and remember, ur work becomes a little shotty after a 6 pack haha.
    HAHA! Good point, Matt!
    Working on a laser projector requires focus, and putting on the "beer goggles" is a sure-fire way to make a mistake.

    Adam

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    I see, I guess I'll just have to dig through a bunch of build logs to see what everyone else has done. I'll be sure to update this thread as I slowly make progress on this - got way too many projects on my mind atm!

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