Ahoy there folks and my inspiration digital dentist (wherever you are in this now silent RepRap universe). Owing to the lack of proper open source, DIYable resin 3d printers, and the hot mess that tariffs has become for my hobbies of late, I have resolved to put my hat into the arena to build one for the benefit of the general-public and the posterity, trying to keep it under $300 apx. So help me O the great noodly monster of the Printverse!
That said, my research has landed me till here so far:
First, this is definitely not going to be an MSLA/LCD based build. Period! Thir availability is dear and far between, at least where I live, and their consumable nature doesn't bode well with the sustainable notion of this DIYable printer relative to the two other options. Its custom PCB requirement was another turn off.
Hence, we have two other options to go about the build:
1. A cartesian XY laser apparatus with a bottom-up/top-down bed system;
e.g. [
www.instructables.com]
Pros:
Cheap and Simple, Rugged if done right. If you can get 9g servos in close loop to run precises enough and slap a relevant laser onto it (mirrored ofc), it may very much be ready to run with a Z-axis and a vat.
Cons:
Slow, unless one uses the costly galvos, scanning is slow. Stepper based galvo solutions are neither fast nor accurate enough in the absence of the f-theta lens which is costly. At least one example exist for a lens free solution (https://www.youtube.com/watch?v=38B44MFpHo0) but haven't explored that too much. Welcome to hear solutions on this one.
and
2. A DLP Projector based printer as was staple in the now dead buildyourownsla.org fora. e.g.:
[
www.instructables.com]
[
www.instructables.com]
[
www.instructables.com]
[
www.instructables.com]
Pros:
Simpleish. Its most complex component, the projector, is ready-made, recyclable, and depending on the modification requirements, dual use (watch a movie on it on the off times).
Many companies like the Elgoo Mars 4DLP and Anycubic Photon 2 DLP are making a comeback to this technology thanks to its longevity.
Have some solid reference builds in DropLit and LittleRP printers (https://github.com/goopyplastic/littlerp2)
Cons:
Most listed projectors on the build your own SLA website are out of even the secondary market. Documentation is out of date and the fora talking about it are long dead.
The DLP Projectors available now to me are:
Refurbished NEC NP40 DLP Lightweight Portable Projector
Brand NEC Image Brightness 2200 ANSI Lumens Type Desktop Display Technology DLP Maximum Resolution 1080i (FHD) Model NEC NP40 Connectivity VGA/SVGA D-Sub, S-Video, RCA Features Portable Native Resolution 1024 x 768 Aspect Ratio 4:3
2) Refurbished Sharp PG-MB60X DLP Projector Product Information With DLP display technology, the Sharp PG-MB60X is a high performer conference, classroom series projector. With 2500 ANSI Lumens, this Sharp DLP projector delivers bright clear images in any lighting condition. The 1024 x 768 native resolution of this Sharp multimedia projector projects true-to-life images with vivid colors. The HDTV Ready feature of this Sharp DLP projector brings crystal-clear high-definition images to your presentation. Whereas, the 1200:1 contrast ratio of this Sharp multimedia projector delivers brightest white and darkest black images. Placed at a distance of 1.8 – 9.1m, the Sharp PG-MB60X projector throws clear images sized 102 – 762cm. Product Identifiers Brand Sharp MPN SHRPGBM60X, PG-MB60X, PG-MB60X SHRPGBM60X UPC 0074000364318 Model PG-MB60X eBay Product ID (ePID) 66747921 Product Key Features Display Technology DLP Image Brightness 2500 ANSI Lumens Contrast Ratio 1200:1 Dimensions Weight 8lb. Additional Product Features Platform M·A·C, PC Products Native Resolution 1024×768 Form Factor Portable Features Keystone Correction
3) Refurbished ViewSonic PJ 506D DLP Projector
Brand ViewSonic Special Feature speakers Display resolution 800 x 600 Display Resolution Maximum 800 x 600 Display Type DLP About this item ViewSonic PJ506D – DLP projector – 2000 ANSI lumens – SVGA (800 x 600) DLP technology delivers crystal-clear images and brilliant color Portable projector is ideal for multimedia lessons in the classroom Support for 720p and 1080i HD signals Features & Specs
Contrast Ratio 2000:1 Lamp Wattage 200 Watts Hardware Connectivity VGA Mounting Type Tabletop Mount Wattage 250 watts Controller Type Button Control Additional Features speakers Native Resolution 800 x 600 Display Resolution Maximum 800 x 600 Display Type DLP Form Factor Portable
4) Refurbished TOSHIBA TDP T45U Portable DLP Projector
Brand TOSHIBA Special Feature speakers Connectivity Technology composite_video Display resolution 1024 x 768 Display Type DLP About this item Portable DLP Projector XGA 1024 x 768 Display Resolution/ 2500 Lumens 2000:1 Contrast Ratio 36 to 300 Inches Image Size/ 11.5 to 100 Projection Distance 7.50 Lbs (WxLxH) 9.00″ x 13.00″ x 3.90″ Features & Specs
Contrast Ratio 2000:1 Maximum Image Size 300 Inches Lamp Wattage 190 Watts Minimum Image Size 36 Inches Hardware Connectivity Composite Video Wattage 1 watts Additional Features speakers Connectivity Technology composite_video Native Resolution 1024 x 768 Display Type DLP Form Factor Portable
From the first Instructable under Option 2:
"....The dose is divided in to three vectors as you will, namely photon energy, light intensity and duration of illumination, together giving the total energy dose. Usually in the UV curing of materials the dose is only measured for a specific part of the spectrum. The rest of the light will usually be reflected or absorbed and converted in to heat.
Only photons with a high enough energy will take part in the photo polymerization. This means that the resin that you will be using is the determining factor in the part of the light (electromagnetic) spectrum that we are interested in. Most photo curing resins will cure under the influence of UV light. Light with a wavelength of between 365nm and 420nm.
Some resins also allow for curing with longer wavelengths but these are usually rare and expensive.
1) One of the things to consider is that in order to be able to print with a wide range of resins we would like as much UV in our light as possible. I will explain this in depth when designing the basin, mirror and anti stick coating.
The other part is time of illumination and illumination intensity. The illumination intensity, or luminous flux is the amount of Photons per unit of time that is emitted by the light source. The longer you illuminate the resin the deeper the light penetrates and the harder and thicker your printed layer gets. This is a very unique feature of stereo lithography where the illumination time is another factor to consider as this determines the build layer thickness.
2) The light source must be of high intensity so the illumination time can be as short as possible allowing for a faster build.
3) An other thing to consider is that the light source needs to be very controllable in switching from illuminating the resin to not illuminating the resin.
In the principle of photo lithography, what gets illuminated polymerizes and what does not get illuminated stays liquid. This means that our resolution or minimum feature size is determined by the minimum spot size.
3) The third parameter for our light source is that it must have the possibility to illuminate a spot that is as small as possible.
Googleing we found that there are two viable light sources/systems that will meet these demands. A blue/UV laser with nice optics to produce a small spot size and a Galvo Head or A DLP projector. A Lasers are cool but to achieve a small accurate spot with a galvo system felt to us as going way over our heads. Since non of us has any experience in setting up a laser, laser optics and a galvo system. And having the guys from Form 1 as an example (patent issues), maybe one day we would like to offer the world a kit too. We decided to go for the DLP projector option.
....As from our considerations in the above we can easily state what properties we want our projector to have:
high UV content (determines if the projector works to cure the resin)
high light intensity (shorter cure time)
high contrast ratio (gives a higher resolution with less light contamination)
high resolution (results in a smaller feature size)"
Given the above considerations, I now looking forward to your recommendations. From hereon, this forum would also serve as the build log of this printer.