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• [T] Shelved -> Researching Project

  kelvinA • 04/28/2022 at 15:58 • 0 comments

  I'm planning to use the abandoned Anycubic Photon my university just happens to have to perform any initial tests. I also want to give PET film a go before going with more taditional film materials to see if this printer method can overcome the "sticktion" issues when using PET in a usual vat. 

  Lastly, I watched the full 49 minute presentation over the course of yesterday and today, and there were 2 things that stood out. The first was that they said that impact modifiers are solid and greatly increase the viscosity, even in small quantities. That sounds like it'll be a beneficial way of converting a standard resin to a VLM process compatible resin, potentially making it better than the current engineering resins on the market. The second was a graph:

  I was focused on the cost per part graph, showing that VLM was the cheapest, even with a large labour cost. As I'm thinking of this in terms of the maker / hobbyist instead of a company, I'm converting "labour" to "post processing time", or the time a person would have to spend to finish up the part after it's done. I'd like to believe that an integrated+automated wash, cure and dissolving wash feature will greatly reduce this time. The dissolving wash is to dissolve solluable supports.

• [R - P2] Plastic film

  kelvinA • 04/27/2022 at 13:09 • 0 comments

  (part 2) More research.

  So it seems that "Inkjet Transparent Film" is usually also PET. There seems to be many options for getting it in A3/A4 sheets, but there aren't many places I've found that has a roll of the stuff.

  • https://all-pervading.com/products/33cm-width-high-quality-inkjet-transparency-film-for-screen-printing-30m-roll?_pos=9&_sid=7fea93aa0&_ss=r

  From this video, I've learned that "waterproof" versions of these kinds of film have more of an emulsion substance on one side than the "non waterproof" version. So far I can't find information on what this material is.

  I'm still on the lookout for cheaper sources of PET in a roll. A 50 pack of A2 laminate pouches (+ £8 shipping) would only cost 96p/sq m. The 33cm x 30m roll of transparency film (+ 20EUR shipping) seems to be £5.05/sq m, implying that there is still room for a lower cost roll. 

  The roll also has to be split somehow if the shorter side of the LCD is to be used (164mm for the M3 Max + maybe 20mm each side). Even for the M3 Max screen of 298mm long, a 12mm gap between resin exposure zones, and perhaps 1m lost on each roll (so 28m of the roll is usable), a 30m roll would be the equivalent of 88 FEP / nFEP sheets that can be swapped electronically with the press of a button, and that's with the 13cm wide roll cuttoff, which could be used on a Photon M3 or Mono 4K (175 or 194 equivalents respectively). It means that, while the film is a consumable, it would be a very slow consumable with little downtime.

  That's only on the assumption that PET works though, as the comments of those that have tried it aren't good. The VLM based design might be more forgiving.

• [R - E1] Plastic film (and resin removal)

  kelvinA • 04/26/2022 at 19:16 • 0 comments

  Ok so I'm doing some quick research and, apparently, PET can be used for the film. This is after I started searching for FEP film. The standard size for the FEP looks to be 0.3 x 1m, which is pretty wide. Perhaps with a laminate paper guillotine, it'll be possible to split it into 2 or even 3 rolls depending on the size of the LCD screen. These guys actually combine both polymers into a multi-layer film. In the video, the FEP looks pretty stretchy, which might cause issues with keeping it taught with rollers.

  Due to the phenomenon seen in this video where light from the LCD will scatter, I can only imagine that a thinner film equates to a sharper image. On the same note, this is probably one of the industries where a lower viewing angle LCD would be preferred.

  But yeah, looking at this part of this video, you don't need any extra viscious resin to get resin that sticks well enough to the film to be suspended over air. It also looks like the plastic scraper already does a good job in removing the resin from the film. Speaking of that video, it seems that FEP issues contribute to printer downtime. As long as the film isn't compromised in a way that would stretch it out, the printer should be able to just move to a consecutive area on the film and continue. I doubt it would be automatic, but perhaps after X amount of layers printed in one area, it moves to the next.

  [27/04/2022] Yes it looks like PET film film will work beautifully.

• [R]

  kelvinA • 04/24/2022 at 16:05 • 0 comments

  If I ever went with the 13.6" screen size option, It's much more likely that I'd start with the M3 Max as the base machine instead of a custom approach. The LCD and light source seem to cost a considerable percentage of a single M3 Max.

  On the other end of the spectrum, the 6" 4K Photon Mono 4K can be purchased for £145 shipped at the time of writing. It also uses Anycubic's slicer, implying that it doesn't require an SDK from Chitubox. However, after analysing what things I'd want to send to the printer, I can only really see this printer used for R+D purposes and parts/models that just happen to fit due to the limited build volume.

  Anyway, it seems that a lot of the components needed for a VLM machine can already be found pre-bundled into a modern MSLA printer. This also simplifies the BOM greatly and should make it much easier to build the printer if designed. I'm not sure about the M3 Max, but I'd assume it'll be possible to 3D print a custom plastic enclosure for the Mono 4K if needed so that it better integrates with the VLM style machine. 

• [R - T]

  kelvinA • 04/23/2022 at 06:04 • 0 comments

  It seems that NanoDLP is the resin equivalent to Marlin or Klipper for FDM. Apparently, I can just use Marlin for motion control, as stated in this relevant subreddit. I'd need 5 if I'm having resin applicators on both sides. Alternatively, I may have to sacrifice one of them for a layer washer / UV cure light.

  As for the screen, I'd like to go with monochromatic (or DLP if that's an option). Either the CanDoTheTaskApp succeeds or fails, so for me, the valid options are 13.6 inches or larger, or a cheap and small screen around 6 inches. Anything in the middle will needlessly affect the CostApp and SpaceApp while not fufilling the CanDoTheTaskApp.

  The pre-sale price might not last, but at the moment it looks like the Anycubic Photon M3 Max is £656 (Listing 1, Listing 2) delivered to UK, which actually sounds pretty nice. I can also see that Anycubic is using their own slicer in the listing, suggesting that there's no need for ChiTu's software. Prometheus and SUMAOPAI also seem to be using the same screen. The reason why I like the 13.6" screen is that the X axis is almost 300mm. Pixel pitch is 46um.

  The front of the Suspense will likely be orientated the same way as the aformentioned printers so that parts like the build plate can be used and without modification. 

  Strongly considering moving this project to ongoing but I'm waiting to see if my initial hype will die down.

• [T] Technology Naming?

  kelvinA • 04/21/2022 at 11:46 • 1 comment

  So, Viscious Lithography Manufacturing is a trademarked process name, meaning that I or someone else needs to think of possible alternative names for this process. I'd like to avoid a Honda / Lego / Disney like situation. 

  Names I've thought of:

  • [Film / Suspended] Lithography Printing
  • [Film / Suspended] MSLA
  • Suspended Film Additive Manufacturing
  • Suspended Masked (Stereo)Lithoghraphy
  • Suspended Film Stereolithography

  As you might be able to tell, I'm biased towards "suspended" and an abbreviation that begins with S. Since the plastic film on rollers is the main thing that differentiates the current form of VLM from top down or bottom up MSLA, I think something MSLA related makes the most sense. 

  Alternatively, there's no reason why the same method can't be used for laser or DLP light sources, so "Masked" wouldn't apply to them. 

  Suspended Liquid Stereolithography has a nice look to it, but there's already an additive manufacturing "SLS", and someone might figure out a way of using powders and a laser instead of UV resin and a UV source to build a part, perhaps though static electricity or a slightly sticky film. Considering that SLS and DMLS are similar processes but use different materials, the same naming convention may apply with this naming situation too.

  I'll continue to think about it.

• [R] Compatible with advanced FDM strategies

  kelvinA • 04/21/2022 at 11:25 • 0 comments

  I've just seen this video which shows all the cool things that can be done in FDM.

  And I realised that the VLM process could allow for the same benefits for UV resin printing! This further puts it a step up from other additive manufacturing methods.

  Now if we could just inkjet some colour on white resin covered film before it's sent to the screen to be cured, that would be, like, Futuristic Additive Manufacturing Bingo!

• [T] Modding an existing printer?

  kelvinA • 04/20/2022 at 12:36 • 0 comments

  Looking at all the MSLA printers on the market, it seems that, hardware wise, everything is already there. The real concern is controlling the additional motors and print process. It's not like the Z axis and all the other motors need to be precisely timed within microseconds, so it sounds plausible that 2 controllers could be used: the first one as part of the doner printer that deals with the z axis motor and the LCD, and the second one for all the additional features needed.

  From research, it seems that anything with ChiTuBox's controller and features a 4K or larger display will need an SDK, for which I'd have to apply for. I'm skimming over the free use agreement but I don't have high hopes by attempting to go down this route.

• [R - T] Screen Choices

  kelvinA • 04/18/2022 at 23:00 • 0 comments

  The decision is simple:

  • Large screen
    • [+] Larger parts
    • [+] Less need for a larger "version 2"
    • [-] Screen more expensive
    • [-] Larger footprint
    • [-] More cleaning fluid needed for the same part
  • Smaller screen
    • [+] Cheaper to build printer / replace screen if it breaks
    • [-] May hide issues that would be experienced when scaling up

  where the benefits of one option are the drawbacks of the other.

  So I thought about the fact that the AvailabilityApp could ruin my entire run, so I instead started looking for possible electronics candidates, starting by avoiding ChiTuBox printers. I discovered the Creality Halot, thought it was a good research session and went to bed. 

  Then I had the idea of searching for DIY MSLA projects. I originally dismissed it, thinking "printers are so cheap these days that there probably wouldn't be anyone trying to make their own these days.", but it only takes a few minutes to check. It didn't take long to find the Prometheus MSLA and I immediately saw the YouTube link. I thought the size of the vat in their most recent video looked like a nice size, and so I went into the discord. There, I find out that they're planning to use a new Anycubic printer called the Photon M3 Max, which has a great sounding screen and build volume.

  My only concern is the CostApp. Anycubic's offering costs more than a monitor stand. I already knew that was going to be iffy and thus the reason the project was shelved on arrival. The SpaceApp was also a factor.
  

  Long story short, I'll be making design decisions with the Prometheus project in mind, assuming that the software part of the equation (excluding slicer) theoretically allows a solution for this project.
  

• Inital Thoughts 2022 Colourised

  kelvinA • 04/18/2022 at 15:07 • 0 comments

  I've just made a minimum viable 3D model to better explain my previous project log.

  • I intend for the printer to also have a built in wash and cure station. 
    • Ideally, I'd like to be able to cure from the top without the use of the LCD panel to increase longevity. 
    • With the screen oriented this way, I can install more LEDs on the walls

    • This also means that the film's unsupported span is shorter than if it were oriented the same way as the vast majority of MSLA printers.

    • The same LED pattern will be on the front window, but more sparse to increase visibility
    • A drawback is that the hardware responsible for resin application will have to be longer
  • The same LED pattern will be on the front window, but more sparse to increase visibility
  • The whole print area will be as "watertight" as needed so that the part can be washed
    • Ideally, the print will be washed as it prints.
      • this might need some kind of sensor to know if any liquids may have splashed onto the resin-covered screen
    • the print likely has to be washed when the material is switched
  • The resin is held inside modules which also have the hardware that applies and retrieves resin from the rollers

    • The modules are on a gantry that will move away from the roller and then move up or down to switch to a new one before pressing against the roller again.
    • An RGB LED is an idea for the coloured dot; the benefit is that it can be dynamically changed easily. However, it would need a power source when the module is stored away. Maybe a 3V coin cell is enough for this. Alternatively, there could be a window/cutout so that the inserted bottle of resin is visible.
    • For the render, I've installed CMYK on the left and White, Transparent, Support, Black on the right
  • The washing fluid will be at the base of the printer, under the max Z location. 
  • A current design concern is that the washing system and/or the curing LEDs might not be able to get to every part of the print.
    • A circular bed instead of a rectangular one could fix this.
    • It might be beneficial to see how dishwashers clean their contents.

  Also, I'm computing a mental simulation and I come to the conclusion VLM technology removes the need to have drainage holes (assuming that the layer height is thin enough for the screen to fully cure the resin), further getting towards the convenience of FDM. It might be required to first print the layer, wash the layer and then cure the inside offset of the layer so that any trace amounts of resin that would be in the part will be cured.

  Other than the resin applicators, this solution doesn't seem that much more complex than a toner printer + dishwasher. Additionally, I haven't done extensive research but I'd like to believe that a hobbyist (chemist) would have a much easier time creating the resin blend (especially since viscosity is less of a constraint) and just being able to use it in the printer, rather than creating polymer pellets and then presicely extruding it through a filament extruder for use in an FDM printer, opening up the possiblility of a maker both designing a custom part and custom material to make it out of. 

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