Good point. I’m not sure yet I’ll use one. I’ve finished assembling my tank yesterday and I feel pretty confident about this FEP plastic, it looks pretty resilient.
I made quite a huge print yesterday, which is the light tunnel for the projector. I want to avoid dust going in the light path as much as possible, since my workshop is always very dusty, so I’ve designed this thing. It will be in two parts, so it will be some kind of retractable system since I’ll need to adjust the projector’s height at some point later. Still need to print the other one.
I’ve optimized my design for high speed printing, so it took only 2 hours:
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I’ve added cooling, because I don’t want the projector to heat the tank too much. I’ll add some filters to catch dust, the fan will blow inside so I can make sure any air coming in has been filtered first.
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I’ve also finished the printing tank and installed the transparent film. you can easily adjust the film tension wit 4 screws on the bottom, and I managed to get it really nice and tight, it sounds just like a drum. I haven’t ainstalled any seal at this point, but yet I made a test to see how bad it would leak. Well it did leak eventually, but that took about 5 minutes and it was only a tiny droplet. So I’m very happy with that, it will work for sure after I’ll add the seals. That part was actually my biggest fear.
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Finally, the whole thing installed on the frame. I think it starts to look nice
A few updates on this project: I was a bit busy since it was the holidays in China and I had a few friends coming home, so I didn’t progress as much as I thought I would.
I’ve installed the projector and tested if the distances and focus were ok. It seems to be all right, but I have an unfortunate issue: this projector doesn’t project straight… It projects at a quite high angle, which I wasn’t expecting (I think it was stupid from me not to check this first, but live and learn). But since I don’t plan on using this projector for very long, I think it should be good enough for testing purposes. The main problem that still concerns me is that the FEP film seems to attract dust like a magnet and I cannot really get it out once it sticks. I’ll need to find a way to solve this situation.
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I’ve made a lot of detailing, which took a while. Putting the screws in the wooden board, squaring everything, and of course, as always, using my signature carbon vinyl wrap to make it faster. I think it looks pretty good and clean now.
I’ve also almost completed the electronics, using a raspberry pi with nanodlp software installed on it, a Arduino Mega/Ramps stack with a special version of Marlin on it, and a big Toshiba stepper driver, capable of more than 3Amps at 24V. The only things I still have to add are the limit switch and a servo shutter, which shouldn’t take very long.
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I’ve tested the electronics and everything seems to work fine. The way it works is pretty interesting, since basically you control the printer from your computer browser through wifi. Everything seems to happen on the raspberry pi, even the slicing, so I think it could work as a standalone printer if you lose the wifi signal at some point (still have to confirm that). So far it works very well, the interface is quite simple and convenient.
I have to say that the MPCNC printer is a gigantic help for this project. It is so nice to be able to print huge parts so fast! It really is the best prototyping machine I ever had: since it is printing so quick I’m not afraid anymore to make mistakes. I just know that if I do it won’t take long to just modify the 3D file and reprint the whole thing, this is actually very relaxing to not have the pressure of screwing up and losing a whole day anymore. Plus now my prints are almost perfect, they are usable right out of the printer with an amazing finish. People are actually surprised it can print so well when they see the machine. The only thing that could be improved would be the top layers, but I’m not really sure I could get them much better since it would involve to get the Z axis dead square, which I can’t seem to be able to do just yet. I’m working on a very different print head system for it right now, which should be pretty innovative I guess, if it woks at all… More to come about that in the next weeks/months.
But for now, I just have a few details to sort out and I should be able to actually test the SLA printer soon!
Oh yeah, projectors have an offset lens so you can mount it on the ceiling and not at mid screen height. Can you just move it your al extrusion and print a new cone?
Don’t you think the first print will remove all that dust?
It seems like it’s not all the projectors, since I’ve seen a few builds and if I recall correctly in most cases the projector was straight. Or maybe those projectors had some kind of height adjustment, I really don’t know.
I’ve just moved and slightly modified my support, it’s not that great but it did the trick. The cone actually works fine so I didn’t need to modify it.
I’m not sure if the dust will move away during the print, but I sure hope so… I tried using a lot of different clothe materials to remove it but none of them worked so far, I guess there is some static electricity making it stick very well on the plastic. My shop is extremely dusty all the time so that really doesn’t help.
I’m new to the MPCNC community and this thread convinced me to make my first post. I’m in the process of assembling my first MPCNC and afterwards I was planning on looking into modifying it to create my own 3d printer using an old LCD monitor. Down the road I wanted to look at making a polyjet printer as well but the jets for these looks even more challenging.
I currently work as a software engineer for B9Creations, a DLP printer startup company in South Dakota. This had made me realize how awesome 3d printers are and the amazing things they can do. This is the first community I’ve joined to start interacting with other enthusiasts.
Another popular film I’ve seen on a number of forums is called PDMS. There are a number of videos available showing how it is applied to the resin vat for printing.
I’ve also heard good things about makerjuice but never used any myself. Another company you might be interested in is called Photocentric. They designed a number of resins to work on printers without UV bulbs.
I would go with a transparent layer to protect the projector but keep it close to the film to minimize the refraction. These machines can get messy despite the best of efforts.
I’m really looking forward to seeing how your prints turn out! Here are a couple of prints I have handy to show the quality these machines are capable of. One is the DW660 mount I forgot to order for my MPCNC :D.
That’s funny, I’ve seen your company’s website a few weeks ago and checked the printers. I don’t remember how I ended up there but the printers looked pretty cool. You’re lucky to work there, I kinda envy you!
I’m very pleased you joined our little community and look forward to see your MPCNC up and working!
I’ve looked into PDMS before setting my mind on FEP film. The main reason was that, apparently, PDMS is not very forgiving and also it doesn’t last for long before beginning to get foggy. I don’t have any experience myself just yet, but according to people who say they do, FEP film can be used again and again as long as there is no incident, like print jam or something falling onto the film, while PDMS will wear out quickly, no matter whatm and especially in the spots that gets the more light (like for instance, if you always place your model in the center of the build platform, then this spot will get foggy after less than a dozen prints). It was also a bit cheaper and easier to find for me. But I keep that in mind in case I have issues later, especially if peeling off turns out to be more difficult than expected.
I unfortunately can’t really find those brands here in China. So I’ve bought 3 different random resins from differents random manufacturers and test them, until hopefully one of these works…
For now I’m just using the FEP film, without anything under it. This thing seems actually pretty tough and flexible, so I’m not too concerned about it breaking anymore now that I’ve seen it in real life. It could still happen if some pointy stuff gets jammed in there, but I’m using a crappy projector anyways so I’ll see during the first tests if this seems to really be an actual risk.
I also have another idea, which would be to put a protective film directly onto the projector lens as well as its surroundings, but I’m not sure if this will work just yet.
That’s some very sweet quality print, but why in hell would you use a low poly model for printing with such awesome machines!!! XD
Thanks for your kind post and keep up the good work!
Wow, I have to say it is a bit odd to see my model in high resolution. I look at them in such detail in CAD but somehow my brain knows to let some details go because they will disappear in the (FDM) print. I am seriously wondering if all those tiny chamfer’s are the same size… hmmmm more attention to detail from here on out.
Welcome to the MPCNC group from another Dakotan (North)!! Where in SD are you at? I’d like to see your company’s stuff someday if I’m traveling through the area.
A few things as a guy who works in the UV LED industry and as someone who bought this to make a SLA printer…
First off, Great work and it looks awesome! So many possibilities! I wanted to mention a couple things for you to consider on this project.
UV resins and the initiators are SUPER toxic until cured. I feel that MSDS don't cover it all (so much is unknown and everyone has proprietary blends, but I know a lot of people that have had sudden cancers from working with it for a few years). PLEASE USE proper PPE and gloves (don't use latex). Put a pan around your machine... resin spills and leaks are awful and toxic and use in a well ventilated room or controlled environment. Most resins that cure visible light photo initiators in general will be more expensive because they don't have the same market demand as ones using UV initiators (although this wasn't always the case). Also, the trend has been, though I might be mistaken, that the resins that cure under visible/white light are far more toxic and exothermic as well.
A major issue with all these systems (and something some people claim to have taken advantage of) is that all UV initiators have issues with oxygen inhibition. This is why people use Teflon (when sold by dupont, FEP, PTFE, fluoropolymer/plastic when not) for peeling systems and many of the more expensive machines don't (many use glass or PDMS). FEP differs from PTFE and regular Teflon in how it's made, chemically and it's properties are typically the same as regular Teflon. Teflon, when thin like used in the resin printers, is semipermeable to oxygen reducing adhesion and curing strength of the resin at the interface (also why all prints from these printers are semi-cured and somewhat soft after printing hence the need for curing boxes or sunlight after printing). ALL FEP films will fail over time and are considered a consumable because this is the nature of the interaction of the fluoroplastic/polymer materials reacting with the uv light, heat, initiators, and resins. The only exception to this seems to be a company who's interface is intentionally oxygen rich to prevent the print from sticking to the FEP and they claim their chemistry prevents clouding/fouling. PDMS can actually be better depending on treatment, type, and substrate it is bonded to. I do agree though, FEP is the way to go on a consumer level product. As you print, you will find the FEP (as strong as it is) will eventually fail due to either stretching or clouding which ever comes first. If you are not motorizing the pulling of the FEP, you will need to make sure it's really secure or you will end up scraping the print off the FEP with failed prints.
UV LEDs are super cheap these days (sub-dollar) per 35mil die, if you have trouble sourcing them or you want to buy a COB, I can help you get one. PM me. You'll want 385-405 nm. 405 is where most resins are targeted if you go outside of this range, you will need more special resins.
Finally, and please I mean no disrespect, you might really want to consider buying one of the cheaper and new LCD based UV printers if your main point isn't just to learn/complete the project... their print quality is going to blow the projected one away at a price point that you can't compete with. The only issue is build area with them, but the print quality is so much better. Even some of the SLA printers are so good now, it's hard to imagine using a DLP to print anymore (though most of the original successful resin printers were DLP and for jewerly and dentistry were the gold standard for high res prints). Attached is an example of a low cost (IE sub 700 USD) machine can do. Better still, you could build one using a LCD (will have better resolution due to pixel pitch than a DLP and it will last longer than the DLP mems mirrors will when exposed to 405 and lower wavelengths). Or you could use a UV laser to do SLA with the space you have there, but the main disadvantage here is the beam size (typically 50-70um). The beam size will limit the performance against the new and faster LCD models. Lots of options excited to see what you do.
Oh also, I forgot to mention, the other reason why FEP became popular…
Mass transfer, the smooth fluoroplastics allow for the resins to slip easily. Prior to their use, when the next layer is built, the resin has a hard time getting back into position for the next layer to be cured. This was solved by many companies either by rocking the bath, swiping the bath, or pulling the bath from the print. Once FEPs were used, this reduced this need, though some companies have issues with mass transfer still due to their build speeds. It’s one of the reasons why exposure times are longer than necessary for the boundary layer to form. It gives time for the resin to return to the interface for curing.
I echo a lot of what David said about this project.
I will also add a little from my experience with the Formlabs Form 2 printer that i bought a couple years ago. It is an SLA printer that uses a 405 nm laser to cure the resin. They sell the replacement vats because they are part of the consumable parts of the printer. Each of the old style vats could be used for about two liters of resin before they had to be thrown out because it gets too cloudy for the laser to shine through. They have a new vat type they call the LT vat. Stands for Long Term I think. It can be used for about 20 liters of resin. You might want to consider buying one of their vats to test with. The dimensions are different then what you have built. Something like 170 X 170. I could measure one of mine at home if you want.
If you search the forums on the formlabs website you can see where people have successfully refurbished their vats. Here is a website that sells a kit. There are a ton of other companies that sell these as well. I only include this link so you can watch the video and see what it entails. https://3dprint.com/79781/druckwege-recoat-kit/
Something else to keep in mind. I have had one vat that was unusable because the coating of FEP was not 100% level. It was probably off by a couple dozen microns. It made part of the print stick so hard to the aluminum print bed that my printer couldn’t get it to peal off. I ended up tearing the FEP coating on accident. It was a brand new vat. So you will want to make sure you can keep your build plate level to the bottom of your vat.
The Form 1 printer used a method to pry the print off of the bottom of the vat. That had a lot of issues. the Form 2 slides the vat on the X axes a little first then it lifts the Z. This works very well. They also have a small squeege that scrapes along the bottom of the vat between each layer to make sure it is clean. I tried disabling it once and that was one of my 3 failed prints I have ever had out of about 120. So I going to say guess that is does help a lot. (If you buy a vat from them it comes with a squeege.)
I would strongly encourage you to ditch the DLP projector and instead move to an LCD. Crack it open and take out the white lamp. Use an UV LED around 405nm. Much better resolution. Just take a look at some kickstarters that are doing similar builds for inspiration.
I absolutely love my Form 2 printer. It is incredible! but it takes a lot of time to clean the parts and post cure them. I even bought an ultrasonic cleaner and the FormCure they sell to make sure it is done right. My only real complaint about it is the cost of resin.
The Olo crashed and burned heavy because it’s dependency on the phone… they required a resin that cured under any wavelength. This was a huge problem and mess because white light is everywhere, where as 405 nm is mostly found outside. And if you think resin is expensive for current resin printers, olo resin is 15 usd for 100ml, or 150 USD for 1L compared to the 30-70USD per L that has kind of become the industry standard pricing.
The Form 2 is awesome, but even some of these new 300-700 USD models out print it detail/throughput wise (due to laser beam size) but the Form 2 takes a lot of the guesswork out of printing and has a better build area than these cheap printers. I think the only thing that makes me not want it is the proprietary nature of Formlabs. XYZ another good SLA company has the same issue but even worse. You should check out some of these low cost ones as you might really like them for detailed projects, but it can’t replace a form 2 when it comes to build volume.
:D. Old bottle of resin on the shelf + <1 hour print time + some parts I needed = ¯_(ツ)_/¯ might as well.
Hello as well! Ready for winter? :D. We are in Rapid City. It seems like we always have someone coming around to view the printers so that shouldn’t be a problem. I’m still impressed when I pull a print off that has a lot of fine details.
Wow, lots of answers this weekend, thanks a lot for the input guys!
Yeah, I'll try to be careful with that. During the first test I plan to do it in an open air environment, but later on the whole thing will be enclosed in acrylic panels and I'll add a fan blower as well a a hepa filter to hopefully catch all the nasty particles. I've done that on some other project so it shouldn't be difficult.
Yeah, I'll see if it works with my current FEP film, I really don't know.
No problem about that, here in China it's extremely easy to find and it costs nothing. I'll stick with the regular projector lamp for the first attemps, since I don't care abour curing times just yet, but thanks!
My point is actually to build the thing to learn how it works, I'm not sure it will ever produce anything decent one day. But given my experience on FDM printers, I'd say that it should be possible to get very nice results even for a DIY device. For instance, my first attempts with the MPCNC at printing giant stuff were absolutely terrible. Now, a few month later, after a lot of fiddling It prints amazingly, even better than a lot of commercial stuff I've seen.
My final goal with this machine would be to produce prints with a relatively accurate and smooth surface, to use them as mould models for aluminum casting. I tried it with the FDM technique and it worked well, but I think the results could be way better with resin. Still a long way to get there, but hopefully, one day…
I’m not sure if this answers your concern, but my vat design is actually refurbishable. I can change the FEP film in a few minutes if I need and re-tension it very easily with 4 little screws. So I could change the film very quickly in case I need to (which I’ll need to do soon since I’ve dropper stupidly something on it and made a little dent)
I’m not sure to undertand, do you mean that the coating on the FEP film was not uniform or that your VAT was not level?
Yeah, I’m not sure if I’d need some kind of physical mechanism to peel the print off. I sure hope I won’t but if I do I’ll think of something, I have a few ideas for that and it could be a good opportunity to innovate and come with a different perspective.
Yeah, that’s definitely the plan. I just don’t want to invest a lot of money on the first prototype, it was just a quick and cheap way for me to test it since I had a projector available. But if this works, my plan is to replace the thing with a HD or 2K screen with a dual system of UV light and white light. I would use the UV light for printing and the white light to make the setup and configuration easier. Or whenever I’d like to watch a movie on the printer.
I’ll see about curing later but it should be easy enough to build.
As for cleaning, I do have a little ultrasonic cleaner so it shouldn’t be an issue. Otherwise I could build some kind of part cleaning device with brushes and jets, could be fun. Or it could catch fire, explode and end up in a giant fireball. Could be fun too.
Lol! I love your personality and approach to this project. I am excited to see it work.
To clarify the level bed comment. I am pretty sure the vat was level but the silicon coating or whatever they use to coat the bottom of the vat so the prints don’t stick to it wasn’t level. It was a little thicker on one side. Almost as if the vat wasn’t level when the coating was applied so it cured un level. I read in the forums that it had happened to some other people as well.
I am not a pro at this resin stuff but if I can help in any way let me know.
Best of luck on this project. I am excited to how well it does.
I don’t think you need a physical mechanism to pull from the FEP, besides it would just add complexity.
I think you’re on the right track, in principle resin printing is easier than FDM (just more messy). I’m excited for you to get this done! Following along.
I haven’t worked on the DLP printer for a while, but it is basically 99% finished. I just need to test it now, I’ve been a bit lazy. I’ve installed the electronics properly and tried the nanoDLP software, which seems really great by the way. It works over wifi so that’s pretty convenient, and it seems actually quite responsive. So far I quite like it, but I’ll need to see IRL if it actually prints fine.
Hopefully I should be able to make the first tests this week.
Meanwhile I had some time to kill this weekend and I had a lot of motors, electronics and stuff hanging in my drawers doing nothing. So I decided to put them all together and build myself another delta printer.
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For this one I went with a 0.6mm nozzle. After a few prints, I now think this nozzle size is really quite a nice compromize between speed and precision. For mechanical parts it is pretty much the best, you get faster and stronger prints, but the quality remains perfectly acceptable for small and intricate details. Pretty happy with this nozzle diameter so far.
