I've been interested in resin based printing almost as long as I've been interested in FDM (filament based) printing. In fact before I got my first printer when I was researching cheap ways to build my own I considered a DLP resin printer design a few times and backed the failed Peachy printer SLA printer.
But - I've always been warned that resin printing is dirty, stinky, requires a lot of post-processing and the resulting parts aren't as functional because they're very brittle and it's hard to get accurate parts due to shrinkage while curing and other issues.
Still, the incredible detail possible intrigued me, and I've had a couple of projects where I've 3D printed small parts and even at 0.10 layer heights was unable to get the detail I wanted. Heck one of the very first things I shared on Thingiverse was a replacement button for my battery charger - and I was never happy with the print quality since FDM lacked the resolution to do the smooth top I wanted: https://www.thingiverse.com/thing:1360018
Being bored with COVID restrictions and trying to find ways to entertain myself I again found myself building a project where I'd have to 3D print some small detailed parts. And while I was able to get usable FDM parts....I just wasn't happy with them. And with the Anycubic Photon 0 being available for <$200 and getting pretty good reviews I figured maybe I'd give resin printing a try.
But the more I read about the Photon 0 and really looked at the reviews critically the more I realized it's a bit limited. It's lower resolution than other low cost MSLA printers and the positive reviews were mostly because of the wash and cure station anycubic released at the same time. So I widened my search and instead looked at the Photon (full photon not the zero) and Elegoo Mars. If my goal was to make highly detailed parts then it seemed silly to cheap out on a printer with lower resolution. (The Photon zero has 115 micro X/Y resolution compared to the 47 micro X/Y of the full photon and mars.) Then I saw a 3rd printer I hadn't heard of before - the Phrozen Sonic mini which really intrigued me despite it's slightly lower 62 micron resolution.
Quick review - SLA is short for Sterolithography. Plain SLA uses a laser to trace out each layer and expose the photosensitive resin causing it to harden. DLP printing instead uses a DLP projector to expose a full layer of resin at once. MSLA which is what most lower cost consumer machines use is Masked SLA where an array of high power UV led's project light through a LCD screen that acts as a mask allowing it to expose a full layer at once. Since DLP and MSLA both expose a full layer at once the amount of stuff on the build plate doesn't change the print time - only the number of layers affects the print time. Which is both a curse and a benefit - if you're just doing a quick test print of one little part it's a curse since it takes just as long as printing a full build plate of parts. But if you're printing that full build plate it's a benefit since it doesn't take any longer than one little test part of the same Z height.
So what makes the Phrozen Sonic Mini attractive despite it's lower resolution? It uses a monochrome LCD which allows more UV through letting it cure layers much faster than other similar printers. The LCD is also a consumable part of these printers that's put under a lot of stress - with the LCD's on most common printers only rated for 500 hours of use...but the Sonic Mini's monochrome screen is rated for 2,000 hours of use. And since you can use shorter exposures that means you rack up fewer hours of use doing the same prints so it can theoretically last a LOT longer. And some reviewers have claimed to get sharper more detailed prints with the Sonic mini than they do with their other higher resolution machines (possibly because of the shorter exposure times, or maybe because being monochrome it's mask is sharper than the color LCD's others use.)
There were two big negatives to the Sonic Mini. 1 - it came with a plastic resin vat which a lot of people reported cracking and being incompatible with some resins. 2 - it's build plate is just a flat sheet of aluminum so resin pools on top and is a lot messier to clean up after a print. Phrozen has addressed both of these issues though - they now ship with an aluminum vat (though they also raised the price of the printer a little bit to compensate) and they offer a upgraded build platform - though it's an extra cost.
At this point I knocked the Photon out of my consideration. It's a nice machine but a bit dated now and has a smaller x/y build plate than the Sonic Mini and Mars. And it turned out Elegoo released an updated version of the Mars that's about $70 more but has a number of nice updates - the Mars Pro. I debated for a few days about whether or not I really wanted a printer in the first place and if so which...and finally pulled the trigger ordering a Sonic Mini.
I ordered from a shop called 3dprintersbay which had an address listed in CA. They advertised 2 day shipping (though not free shipping) but said it was 3-6 days from when you order until they ship. The printer was out of stock on Amazon at the time and 3dprintersbay offered the upgraded build plate for just $20 when ordered with a new printer compared to $40 to get the upgraded build plate off of Amazon. What they didn't make clear was that they basically just drop-ship from the manufacturer. And 2 days after I ordered Phrozen took a week long holiday for their local "Dragon boat festival" in Taiwan. After 2 weeks my order still hadn't shipped and I started to wonder if it ever would. I sent a message to 3dprintersbay inquiring and when I didn't hear back in 24 hours I decided the printer probably wasn't coming and got ready to call my credit card company and paypal to reverse the charges.
I also went ahead and ordered an Elegoo Mars Pro off of Amazon. Then a few hours later 3dpritnersbay finally responded and apologized for the delay explaining that they were waiting on Phrozen who also replied saying it should ship in the next 2-3 days. I wasn't convinced enough to cancel the Mars pro....though I was a bit upset that my original plan of getting a $170 printer had now turned into buying 2 $250+ printers. Oops.
But - I figured this is a good opportunity to compare the two printers and then I can sell whichever one I'm less than happy with.
The Mars pro arrived last Thursday and the Phrozen sonic mini arrived the day after. For the past week I've been printing like crazy and have learned a lot about resin printing in general, both machines quirks, and why this is a terrible time to get into resin printing.
How do they compare? If I had to buy one today knowing what I know which one would it be? What have I learned about the process overall?
Let's find out...in my next few posts
But - I've always been warned that resin printing is dirty, stinky, requires a lot of post-processing and the resulting parts aren't as functional because they're very brittle and it's hard to get accurate parts due to shrinkage while curing and other issues.
Still, the incredible detail possible intrigued me, and I've had a couple of projects where I've 3D printed small parts and even at 0.10 layer heights was unable to get the detail I wanted. Heck one of the very first things I shared on Thingiverse was a replacement button for my battery charger - and I was never happy with the print quality since FDM lacked the resolution to do the smooth top I wanted: https://www.thingiverse.com/thing:1360018
Being bored with COVID restrictions and trying to find ways to entertain myself I again found myself building a project where I'd have to 3D print some small detailed parts. And while I was able to get usable FDM parts....I just wasn't happy with them. And with the Anycubic Photon 0 being available for <$200 and getting pretty good reviews I figured maybe I'd give resin printing a try.
But the more I read about the Photon 0 and really looked at the reviews critically the more I realized it's a bit limited. It's lower resolution than other low cost MSLA printers and the positive reviews were mostly because of the wash and cure station anycubic released at the same time. So I widened my search and instead looked at the Photon (full photon not the zero) and Elegoo Mars. If my goal was to make highly detailed parts then it seemed silly to cheap out on a printer with lower resolution. (The Photon zero has 115 micro X/Y resolution compared to the 47 micro X/Y of the full photon and mars.) Then I saw a 3rd printer I hadn't heard of before - the Phrozen Sonic mini which really intrigued me despite it's slightly lower 62 micron resolution.
Quick review - SLA is short for Sterolithography. Plain SLA uses a laser to trace out each layer and expose the photosensitive resin causing it to harden. DLP printing instead uses a DLP projector to expose a full layer of resin at once. MSLA which is what most lower cost consumer machines use is Masked SLA where an array of high power UV led's project light through a LCD screen that acts as a mask allowing it to expose a full layer at once. Since DLP and MSLA both expose a full layer at once the amount of stuff on the build plate doesn't change the print time - only the number of layers affects the print time. Which is both a curse and a benefit - if you're just doing a quick test print of one little part it's a curse since it takes just as long as printing a full build plate of parts. But if you're printing that full build plate it's a benefit since it doesn't take any longer than one little test part of the same Z height.
So what makes the Phrozen Sonic Mini attractive despite it's lower resolution? It uses a monochrome LCD which allows more UV through letting it cure layers much faster than other similar printers. The LCD is also a consumable part of these printers that's put under a lot of stress - with the LCD's on most common printers only rated for 500 hours of use...but the Sonic Mini's monochrome screen is rated for 2,000 hours of use. And since you can use shorter exposures that means you rack up fewer hours of use doing the same prints so it can theoretically last a LOT longer. And some reviewers have claimed to get sharper more detailed prints with the Sonic mini than they do with their other higher resolution machines (possibly because of the shorter exposure times, or maybe because being monochrome it's mask is sharper than the color LCD's others use.)
There were two big negatives to the Sonic Mini. 1 - it came with a plastic resin vat which a lot of people reported cracking and being incompatible with some resins. 2 - it's build plate is just a flat sheet of aluminum so resin pools on top and is a lot messier to clean up after a print. Phrozen has addressed both of these issues though - they now ship with an aluminum vat (though they also raised the price of the printer a little bit to compensate) and they offer a upgraded build platform - though it's an extra cost.
At this point I knocked the Photon out of my consideration. It's a nice machine but a bit dated now and has a smaller x/y build plate than the Sonic Mini and Mars. And it turned out Elegoo released an updated version of the Mars that's about $70 more but has a number of nice updates - the Mars Pro. I debated for a few days about whether or not I really wanted a printer in the first place and if so which...and finally pulled the trigger ordering a Sonic Mini.
I ordered from a shop called 3dprintersbay which had an address listed in CA. They advertised 2 day shipping (though not free shipping) but said it was 3-6 days from when you order until they ship. The printer was out of stock on Amazon at the time and 3dprintersbay offered the upgraded build plate for just $20 when ordered with a new printer compared to $40 to get the upgraded build plate off of Amazon. What they didn't make clear was that they basically just drop-ship from the manufacturer. And 2 days after I ordered Phrozen took a week long holiday for their local "Dragon boat festival" in Taiwan. After 2 weeks my order still hadn't shipped and I started to wonder if it ever would. I sent a message to 3dprintersbay inquiring and when I didn't hear back in 24 hours I decided the printer probably wasn't coming and got ready to call my credit card company and paypal to reverse the charges.
I also went ahead and ordered an Elegoo Mars Pro off of Amazon. Then a few hours later 3dpritnersbay finally responded and apologized for the delay explaining that they were waiting on Phrozen who also replied saying it should ship in the next 2-3 days. I wasn't convinced enough to cancel the Mars pro....though I was a bit upset that my original plan of getting a $170 printer had now turned into buying 2 $250+ printers. Oops.
But - I figured this is a good opportunity to compare the two printers and then I can sell whichever one I'm less than happy with.
The Mars pro arrived last Thursday and the Phrozen sonic mini arrived the day after. For the past week I've been printing like crazy and have learned a lot about resin printing in general, both machines quirks, and why this is a terrible time to get into resin printing.


How do they compare? If I had to buy one today knowing what I know which one would it be? What have I learned about the process overall?
Let's find out...in my next few posts