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• [A] "SecSavr" is being depreciated

  kelvinA • 10/02/2024 at 15:50 • 0 comments

  This isn't a sudden decision. Instead, it's a feeling that has slowly been chipping away at me.

  For starters, the original reason I thought of the name SecondSavr is so far removed from what I'm trying to do these days. It's like a "Test Drive Unlimited Solar Crown" situation, where I personally think it should just be "Test Drive Solar Crown". Why? Well "the title is getting long" is a reason, but my main one is that "Test Drive" is the brand and "Unlimited" was the name of the game: a new play mode of open world. "Unlimited 2" understandably built on that. Solar Crown, while being an open island game, changed a lot of stuff -- enough that even the developers didn't call it "Unlimited 3".

  Additionally, the project is currently needlessly separated apart. As you may know, #Coaxial8or [gd0144] is currently my furthest-ahead project that isn't "finished" (e.g. like #WK-50 Trackball Keyboard) and I see it a bit like a template of how other projects might play out: Design some ideas, make some prototypes, it grows into the project we see today; that kind of thing. There's also the #Teti [gd0022] kind of project, where you try and make X and then realise there's no off-the-shelf component so now you need to invent Y. SecSavr Suspense is essentially like Coaxial8or but split apart almost like Teti. For example, SuLotion is still a shell after all these months:

  I also want to avoid a Notkia situation:

  Thus, I'm going to think up a new name that tries to embody one of the reasons I called this printer Suspense in the first place: The suspense in anticipation that Liquid Laminate Lithography can achieve most of the benefits of PolyJet with minimal drawbacks.

  In the meantime, I'm going to archive / delete other projects such as #SecSavr Soapalai [gd0146]. 

• [R] Laser Tree K30 can sinter 316L powder

  kelvinA • 07/16/2024 at 04:12 • 0 comments

  I was looking through the SLS4ALL discord when I found out about the Metal Base project, which aims to specifically print stainless steel 316. 

  Only using 316L metal powder, our extensive testing has shown that using this material in combination with the relatively low laser power does not generate any fire hazard even when used in open air with 20% oxygen content.

  I wonder if this is the reason JLCPCB's only metal print material is 316L. 

  Looking through their YouTube channel, I was able to find out that a Laser Tree K30 -- a 33 - 35W output power laser -- was used. This laser has a spot size of 0.16 * 0.19mm, meaning that it comparatively has the same irradiation intensity as a 0.08 * 0.08mm 7 - 7.4W laser. The price is £375, which was where 20W lasers used to be. Today, the V20 laser, still my most ideal candidate, is only £240. All Laser Tree's modules seem to have the same spot size, which would need to be 95W to match the V20 on intensity. Their current top-end is a staggering 60W, which actually is still priced at the same £/watt as the V20 (it's around £750).

  Something to note is that the K30 claims to use 10W less input power than the V20 (120W vs 130W), suggesting that its 6 diodes are more efficient. It actually seems that each 11W uses an additional 24W of input power:

  Below is the result of a bottle-opener they printed:

  There doesn't seem to be any video where the part is actually removed from the build plate. I theorise that it's welded onto the plate and has to be grinded off, and then ground again off the supports. Not entirely ideal for a consumer-oriented perspective and why I hope L^3 can do metal + support in a single print job.

  They have an enclosed but not entirely airtight enclosure and use an air compressor (capable of 8 bar continuously without overheating) to reduce oxygen content in the air to 5%, allowing for optimal printer performance.

  The system works by using a CMS (carbon molecular sieve) material in 2 separate air tanks that are switched between filtering and cleaning state. This is called the pressure swing absorption process.

  Their price target is >$6K for the machine.

• [A] Putting design effort into Soapavr (gd0146)

  kelvinA • 07/15/2024 at 07:18 • 0 comments

  I'm planning for the main ground-floor level project logs to be written on #SecSavr Soapavr [gd0146], with the Suspense being the "this could be all the possibilities"-type research project. I just like to have the peace-of-mind that I didn't implement feature XYZ because I weighed the pros and cons and not because I didn't even know it was a valid option in the first place.

  The name could use some work though. It's no longer the shape of a bar of soap nor is a stepping-stone project, so it's now tough to get branding-energy behind it (unlike #Coaxial8or [gd0144] for example).

• [R] Mellow Fly D7: Cheap 7-stepper motherboard

  kelvinA • 02/05/2024 at 05:07 • 0 comments

  Just like with the 8-stepper Bumblebee, I was once again looking around for motherboards because of my Coaxial Hotend project and came across this:

  This Mellow Fly D7 v1.0 board is low cost, compact and has all the things that I actually need (UART-enabled stepper ports) and trims out many of the things that I don't (since they'd be on the Manta M8P V2.0). 

  The most notable ommision are EXPn, meaning that I'd only be able to use 1 motor expander (on the M8P). That should be fine, as with 2 Fly D7s and 1 BTT EXP MOT, the printer will have 25 steppers to work with.

  It might be useful that CANBUS devices can be connected directly to the board without a separate transceiver.

• [R] BCN3D splits VLM business into Supernova

  kelvinA • 02/03/2024 at 18:42 • 0 comments

  It seems that more tech innovation news happened on Feb 2 than customers getting their hands on the Apple Vision Pro or me getting some test prints from the 4-in-1-out Coaxial Hotend. 

  I've just read on Fabbaloo that a company called Supernova has spun off from BCN3D and taken VLM with them. That sounds good considering BCN3D has been rather quiet on what I believe is a notable technology and the writer, Kerry Stevenson, ended the article with this:

  Someday it may be that Supernova eclipses BCN3D in size, especially if manufacturers catch on to VLM.

  Interestingly, this company is headquartered in Austin, Texas, which I assume is because that's where the US engineering talent pool seems to be outside of California.

  They had an event and here's the things that stood out to me:

  • It runs though as much as 2.5kg/hr.
  • It can print 2 materials in the same layer.
  • They can print in silicone's. The last time I read about 3D printing in silicone's, I heard it was quite involved (involved enough that there are a handful of companies that specialise in 3D printing silicone).
  • The maximum solution price has increased from "under $50K" to "under $100K".
  • They're re-opening the tech adoption programme.

  There was also a short clip of the actual printer printing:
  

  The XY resolution is 23 microns, so this must be one very high pixel-count LCD considering its size.

  Now I'm looking though their website and I'm already liking the sounds of the materials. For example, the longer oligomer chains reduces undesirable biological effects:

  This is important for wearable electronics, or parts that will experience a notable amount of skin contact (e.g. keyboard keys).

  Then there's the filled materials in 3 flavours: ceramic, metal (such as copper) and fiber:

  All 3 of these are materials I'm excited about; ceramics and copper for electronics and then magnetic fibers with Fortify's fiber-aligning tech.

• [X][T] Q8100-60002 uses the AMIS-722402?

  kelvinA • 02/01/2024 at 07:48 • 0 comments

  I did some looking into the printer series' that this scanner is used in, and all but one of them has "optical resolution: 2400dpi". Now this is actually really high, as resolutions in the datasheets that exist online are 200, 300, 600 and one or two 1200dpi. I looked into a handful of other sensors on AliExpress and the printers that they're used in have a 1200dpi scan. 

  The one used in #Magic Frame : Turn Everything into a Touch Area had 2700 pixels. For 216mm of scan length, a 2400dpi scanner would have at least 20,410px!

  Thus, I looked for a 2400dpi CIS chip, assuming that HP wasn't going to invent their own. The only thing I found was the AMIS-722402, with datasheets online (with the sharpest looking to be from Arrow as a PDF download).

  14.56mm wide per sensor chip means that 15 sensors would be put together to get over 216mm, resulting in 218.4mm of scanning length and 20,640px.

  By looking at other sensor datasheets, one of the things I noticed is that the communication protocol is rather standardised. There's a pin that starts the scan, a clock signal and, some N number of cycles later, the "video out" (aka sensor data) gets read 1 pixel at a time.
  

  For this chip, the clock is typically 2.5MHz but it sounds like the engineers expect the fastest, 3MHz, to be used more.

  So I was thinking to myself "That's all great and all, but shouldn't there be like some kind of examplar circuit in here?" and there was one at the back. I think I'm onto something:
  

  I looked at the pinout here and many of them lined up with the pinouts determined in the past. One of them that was close but not quite was the assumption of "GND but not connected directly to the other GND" pin 3, and this is why:

  Technically, the pin can accept 0V, but it's actually expected to use 0.35V and determines the black-level voltage:

  Then there are select pins that determine how high a resolution is scanned. Lower resolutions bin pixels together, making them proportionally more sensitive.

  I connected the LEDs and found that Pin14 is LED Positive. I expected the entire white section to illuminate, but it's only a strip next to the lens array. I also found out that

  1. Red: Hits the set current limit of 200mA and thus drops till 2.17V
     1. Increasing the current limit didn't seem to make the LED brighter nor increase the voltage, so I tried a lower one.
     2. 2.2V was at about 150mA and slowly climbing
     3. 2.1V was notably dimmer, and 2.0V dimmer still.
     4. Thus, it sounds like I'm going to need a resistor on LEDR.
  2. Green: 5V at 107mA
  3. Blue: 5V at 166mA

• [A] Details page before 11 Jan 2024

  kelvinA • 01/11/2024 at 11:07 • 0 comments

  I'm finally starting to revamp and equalize all my details pages so that the projects can be better understood and information hidden within the depths of logs can be more easily found. The below is the old Details page.

  ---

  [16 April 2022]

  So I'm going about my day and I see a link in a Discord channel to this video:

  Now, looking at the logo and red material that looked like paint, my expectation was that there was some marginally new resin technology and BCN3D was trying to make a new buzzword out of it. 

  I'm like "BCN3D. I get it. You're now getting into the SLA business and it's all new to you from an FFF standpoint.", waving jazz hands. "But can this 3D printing industry stop over-hyping marginally new technologies like it's the next generation of 3D printing??"

  However, everything changes when I get to the 30 second mark of the video and it's revealed that the camera actually isn't upside down for visually nicer footage and that the resin is seemingly suspended in air somehow.

  As soon as I see that the resin is stuck to a film, I'm like "AGHHHH!!! That's so simple, so obvious now that I've seen it! How has Me In The Past (or anyone else in the hobbyist 3D printing community) not thought of this?!"

  I'd love to end the thought there, but I've been thinking about what could solve the single-material and uncured resin handling issues of MSLA and what could bridge the gap between hobbyist machines and PolyJet. The reason I've never gotten an SLA printer is because, unlike FDM, the majority of my planned prints would be multi-colour, the uncured resin is toxic and the parts aren't ready fresh out of the machine.

  • Me In The Past thought of a multi-vat approach where one of the vats would contain cleaning fluid. There would be 3 or 4 vats and the centre Z column would rotate around to switch to them.
    • "Ahh but cleaning and moving would take so much time over the print job!"
  • Ok, what about a floating resin solution where the cleaning fluid is denser than the resin? With that, the part can just move down and be washed and cured while waiting for the previous resin to be sucked back to its reservoir and the next material is pumped in. This also means that you don't need much more space or more screens to add support for more materials available in a print job.
    • "Ahh but how would that deposition stay consistent. Isn't that a fair bit of plumbing work? And top-down approaches are susceptible to the machine being shaken or unlevel."

  So after I saw the video, I thought:

  • "That's it! That's the solution!!! Ouwgh but I don't want to wait until 2042 and beyond [to use this technology]. And it doesn't even seem like they've unlocked its full potential yet. I'm thinking like 8+ materials and washing during (or after) the print process before fully curing the part."

  Thus, this project is mainly for me to do something -- anything -- to inspire someone with the ability to research / develop this kind of printer into reality, if I haven't done so myself. Other reasons are so that I'm not keeping ideas in my head (writing Future Me some documentation to work with) and so that these ideas are in the public domain, meaning that any future patents can't be too vague and over-reaching.

  SecSavr Sol^2 [gd0045] is the slicing software for this machine.

  SecSavr Syrum [gd0141] is the project for materials research.

  This log here is where I'm posting little comments, though some of them are so large that they should've been actual logs.
  

• [E1][A][R] I'm so back (for the 100th log)

  kelvinA • 08/08/2023 at 17:02 • 0 comments

  This isn't exactly what I had in mind for the 100th project log, but a few days ago...

  ... three, actually, I put all the SecSavr projects on the shelf because my highest priority project, #Tetrinsic [gd0041], expectedly hit a snag when trying to bring it out of the virtual and into the real world. I was thinking "Ouch. If this is what perils await me for a project that only has a few components, perhaps I should be realistic and shelve the research and design of a 3D printer, its printing software and its materials science research for some time in the distant future.", partially because I recently watched this Meta Quest AR mod whereby the designer went from start to finish in 6 months and his original concept was very similar to the final device, unlike Tetrinsic which has changed numerous times in its 19 months of development.

  Additionally, a few more days ago, I got onto the hopium train as they're now serving the room temperature superconductor LK-99. It's an inspiring ride that is best summed up by the following image going around:

  Most of this induced hopium energy has actually gone to being mentally prepared to continue tackling #Coaxial Hotend [gd0144], understandably because I'm essentially validating a discovery from Nozzleboss just as scientists around the globe are validating LK-99. I had to get off the train since, as you can see by the graph, the time period between evidence suggesting one or the other was getting shorter and shorter

  After shelving the SecSavr project, I went and researched other 3D printer projects, such as these below:

  The things I was able to gather was that

  • The material holders, due to their weight, probably should use a T12 leadscrew. However, in the persuit of longevity and minimal maintenance, multiple projects advise the use of ballscrews (with a decoupling mechanism)
  • It's possible to use 2 linear rails seperated by spacers to emulate an I-beam for rigidity.
  • If I actually had the skill, it would be possible to design the printer at a faster rate (based on the 4 months in 6 minutes video)

  Additionally, I found some articles on All3DP when searching for full-colour 3D printers:

  • https://all3dp.com/4/colorize-your-lithophanes-with-bambu-labs-cmyk-filament-bundle/
    • More relevant to Coaxial Hotend
  • https://all3dp.com/addwii-enters-market-low-cost-full-color-3d-printing/
  • https://all3dp.com/worlds-first-full-color-paper-3d-printer-for-your-desktop/

  But the notable articles that eventually lead to me reversing my decision on SecSavr were these:

  • https://all3dp.com/2/diy-resin-3d-printer-sla/
    • At the time of writing, only 5 printers are on this list. It seems that only designed + built printers are on here, and no work-in-progress printers.
  • https://all3dp.com/4/bambu-lab-p1p-price-drop-first-gen-printers-a-55-100/
    • Which is a post about https://blog.bambulab.com/bambu-lab-anniversary/
    • With Tetent in mind, my takeaway from this blogpost is that I can put out a device that, while comparatively better than the competition, it's only partway where I wanted the solution to be. 
      • Personally though, I don't strive for "Better than the competition", but "It's just Better(TM)". I want something that I can finish and still use 5+ years later without a single change (which is a lower bar than it sounds, considering all my not-so-temporary temporary gear).
    • Bambulab is aiming for a printer with the kind of consumer-level maturity as an iPhone, and that's the reason why they only rate themselves 55/100.
      • (meanwhile I'm tilting my head like "Yeah... I'd put a 45, but that's primarily because I'm not a fan of sub-300mm printers and partially because I was hoping that a printer like the X1C would've existed in 2020, thus I was loosing hope by the time it rolled around in 2022.")
      • (But really though, it's only an extra 5cm for each axis! Hopefully, BambuLabs is developing a competitor to the Creality K1 Max, which is a 300mm competitor...

  Read more »

• [E1][R] Laser Decision for Copper Sintering: 20W VF20

  kelvinA • 06/06/2023 at 14:59 • 0 comments

  The BOM has been rather stable, with the only thing that I wasn't sure about being the laser. I was considering a 5W 0.08*0.08mm spot laser for the #SecSavr Soapavr [gd0146], but more research shows that a 20W laser with a sufficient spot size is the way to go.

  Firstly, I was looking at the cutting depth of stainless steel with these kinds of wattages, and it seems that 0.08mm thick is possible so that's good enough for me:

  Then, I was looking at the recently announced 30 - 48W lasers. Unfortunately, there's some issues. Some of them have spot sizes that are 0.1*0.15mm or larger, meaning that the kW/mm^2 is still at around 20W laser levels. Most of them are 750g or heaver, as well as having dimensions exceeding 60x60x130mm. All of them are near or over 2X the price of the ZBAITU VF20 that is possible to get under £300 on sale.

  The next video I saw was about copper laser welding, which is essentially what I'm trying to do here.

  One of the cool things is that the tests were done without shielding gas. Anyway, the below slide is important:
  

  The 450nm laser used has a dot diameter of 0.6mm. Thus, for a 1kW laser, the power density is 3.5kW/mm^2. As you can also see from the graph, 100um depth is achieved at 600W, or 2.12kW/mm^2, for a travel velocity of 50mm/s.

  The VF20 has been measured to output 21.5W, though the meter also says "Wavelength: 600nm" even though this is a 445nm laser:

  The listing on Aliexpress says that the spot is 0.1*0.08mm, but their website says 0.08*0.08. I know that, when it released, the spot was the former, and it's possible that, after almost a year of making these modules, they've been able to shrink the spot size to 0.08*0.08mm. 

  They've also got a similarly priced XF20 that has a 0.08*0.08mm spot size claimed in some listings and 0.06*0.08mm claimed in others. While I find the flame detection and laser crosshair useful, it's height of 130mm with the air assist inlet on the top (meaning I need even more height clearance) and weight of 700g makes it harder to integrate compared to the 80mm tall, 364g VF20. The XF30 also shares the same build as the XF20.

  Power densities of the options:

  Power (W)	Spot Size (mm*0.08mm)	Power Density (kW/mm^2)
  20	0.10 0.08 0.06	2.5 3.125 4.166
  21.6	0.10 0.08 0.06	2.7 3.375 4.5
  30	0.08 0.06	4.688 6.25
  32.4*	0.08 0.06	5.062 6.75

  *Assuming 5.5W diodes output 5.4W of power
  

  Conclusions

  • Obviously, the main conclusion I can take from this is that anything under 20W is unlikely to work. It also makes a bit of sense, since 10W and 5W lasers have existed for a while and yet there are no 3D printers that use them to sinter copper, but these 20W+ lasers are very recent and so it's possible that printers that use them are still in development.
  • It does seem like the spot size really affects the power density.
  • Coming in at about £575, it's unlikely that I opt for the 30W laser.

  [9 Jun: Edit 1]

  I'm just going to assume that the below specs are accurate:

  This is a 84W laser, the same as the 84W UV LED I'm planning to use for the #SecSavr Soapavr [gd0146]. I wonder if I should try powering the system on the 24V 5A (120W) power supply this comes with. Then again, since both L^3 SecSavrs have more things to power than a typical laser cutter, I should stick with a 200W PSU. 

  Then again, it could be benefitial to go with an external PSU, meaning that DIYers don't need to deal with mains connections at all (even if it's just screwing 3 terminal blocks).

• [A] SecSavr Soapavr [gd0146]

  kelvinA • 05/07/2023 at 13:09 • 0 comments

  The SecSavr Suspense is quite large and I think it's slowing down my development as I feel the stakes are higher. Additionally, I can't make much (if any) progress towards #SecSavr Sol^2 [gd0045] or #SecSavr Syrum [gd0141] without actual hardware. 

  I already knew about all this last year and that's why I started thinking about the SecSavr SuspenseSmall, but its phyiscal size (more important in regards to development) and BOM cost (less important) grew so large that it couldn't really fufull its initial goal of having something that can fit somewhere in a house (without having to plan for it like a new furniture item) for a somewhat paletable investment cost.

  Thus, I've created a new project:

  #SecSavr Soapavr [gd0146] 

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