3D Resin Printing, Anycubic Photon etc

[Chris J]

I see the Anycubic Photon 3D printer  has got a mention on here.  I've had one for around 8 months or so and thought my experiences and  impressions might be worthwhile posting.
Firstly, what is it? It's a resin DLP 3D printer, about 8 inches square and 16 inches high (talking imperial for our US cousins). It is light enough to carry around easily so can be put away when not in use rather than taking up desk space if that is an issue. It is capable of printing layer thicknesses of 0.1mm down to 0.025mm. The build area is rather small at 115mm by 65mm by 155mm high but prints can be sliced up in software and printed separately. Googling it will show what one  looks like, I'd post a picture of mine but it is covered in resiny fingerprints because I am rather messy.
How does it work?  Basic important parts are a vat for resin, an LCD screen and a build plate mounted on a screw Z axis. The vat  has a clear bottom and is placed on top of the LCD screen and the build plate is lowered down until it is just above the bottom of the vat. Files to be printed are copied onto a USB stick which is inserted into the USB port on the side of the printer. A touch display screen on the front of the printer  is used to select the files,  manipulate the printer settings and pause or cancel the printing process if needed.
When the print is commenced the LCD will illuminate at the places where the print should form. (The length of illumination is user-defined  and depends upon the resin type, layer thickness and so on.) hardening the resin at that location. The build plate will then move up by the defined thickness and the LCD will again illuminate at the places where the print should form. This is repeated until the print is finished, whereby the build plate will wind itself to the top of the Z axis and the print will be suspended upside down waiting for removal. This is done with either or plastic scraper or more likely a steel one, depending on how well the print has stuck. The print is then sloshed in a container of Isopropyl Alcohol to wash off the remaining resin, then hardened with UV - either using a UV light or because I live in sunny Sydney, plonking outside for half an hour.

How long does a print take? This depends upon the LCD illumination time, the layer thickness, and the height of the print. My usual settings are 15 sec LCD on time and  0,05mm thickness so something an inch high will take just over 2 hours. The bright side is that if you have say 20 x  one inch high things, assuming you can put 20 of them onto the build plate at the same time, it will take no longer to print 20 than it takes to print one!
What about software? A slicer application is required in order to convert 3D format files into the .photon format that the printer reads. The OEM softare is the Anycubic slicer which does the job, plus allows you to rescale prints, copy and paste multiple copies of prints onto the build bed and create supports for prints that require them.  There is another package called Chitubox (also freeware) upon which the Slicer application is based which can be used as well.
Are there any problems? Yes there are. The usual one is you regularly open the printer after you've left it on all night to do an 8 hour print to find that there is nothing on the build plate and only a thin layer like a pancake in the resin vat. The usual cause of this is either incorrect settings (eg the time you chose to harden the initial layers – a separate setting from the LCD on  time – was too short, or more likely the build plate was not level.
The buildplate levelling process is a crucial but inexact step and is the first thing to do when setting up the printer. The official method is to slip a piece of paper onto the LCD screen, loosen the screw that locks the build plate to its swivel mount then lower the build plate down until it touches the paper so the paper can be pulled out evenly but not pushed, at which point the screw is tightened and the home location button on the printer display is pressed.  This defines the home position which is then stored in the printer. Since this is open to a users interpretation – how thick should the paper be, how easily should I be able to pull the paper etc, the levelling process does not always work  and is the source for the most frustration among users. Personally I find myself having to relevel after every half a dozen prints. I believe the way I handle the build plate when trying to remove the finished prints puts pressure on the swivel joint and might move it slightly.
Is it expensive? Compared to other printers, and considering what it can do, no it isn't. Amazon for example has frequent sales on  it where it can be got for around  $350 Us, other sites have similar prices at times . The resin is fairly dear,  however there are various brands that can be used in it apart from the Anycubic one so keeping an eye on sales sites will often popup specials on particular brands or colours and transparency.
The LCD should be considered a consumable since they do fail and in addition it is scarily easy to crack the glass if you press the 'down' arrow instead of the 'up' arrow when levelling the bed! (Yes, I have done this...). Additionally the clear base of the vat is a polycarbonate sheet called a FEP sheet. This also gets scratched and hazy and needs replacing at inervals. The more gently you treat it (eg only wipe with microfiber cloths, not paper towels) the longer you'll get between changes.
What are the good points?  Fantastic detail for a reasonable price, large helpful user community and a fairly responsive help network when things go wrong would be the main ones.
What are the bad points? Resin can be messy and should not be handled without protective gloves, some find the smell a bit strong (I personally don't). Cleaning up is a bit of a process and requires IPA, however the vat does not need to be emptied after every print session – it can be taken out with remaining resin still in it and stored in a cool dark drawer or cupboard it will last as long as if it was tipped back into the bottle. The post-processing of the prints can be messy also, prints need washing in IPA to remove excess resin, then cured with UV.
This is just a quick rundown to outline the printer basics, when I get a chance over the next few days I'll go into the actual prints themselves and my impressions of the job it does...

[Hydrostat]

Chris,

thank you very much - this is very informatove and helpful!

Volker

[Hauk]

Thanks for sharing!
This is very helpful for us who are thinking about getting a machine like this.

[Bill Gill]

Thanks, Chris. Good information. I have read that some resins used by Shapeways are intended for short term prototyping and they become very frail and brittle and do not hold up well over time. Do you know anything about the longevity and strength of resins used by the Anycubic Photon printer?

[finescalerr]

You are going to be busy here for a while, Chris. I think almost all of us are very interested in what you have written and will write, especially when your answers and descriptions can include a photo.

Your comments suggest 3-D printing is messy, cumbersome, and requires a lot of trial and error before the modeler is able to get good results. How long did it take you to become pretty good at printing?

A few minutes ago I signed Uwe Wettin, from Germany, into our forum and he probably will post on this thread pretty soon. Uwe worked with Volker to produce those tiny cups and saucers.

3-D printing may still be in the early stages of development but it is obvious an affordable printer like the Photon could become a very important scratchbuilding tool. The more we learn here, the better. Along with patience and steady hands, technology is becoming crucial to the future of modeling. I need to sharpen my SketchUp skills!

Russ

[Chris J]

G'day Russ,

I don't mind answering questions - in fact because down here it is around half a day in the future due to time zones I have usually read them before you have even posted them... Weekends I am usually pretty busy but during the week I will be able to take enough time here.

Firstly, the printing process is messy for me because I am just a naturally messy person. That bloke in 'Peanuts' with the dirt cloud around him - that is me. My desk has the coffee cup  rings all over it, and my printer and worktop is covered in sticky resin drops and smears. All the Photon youtubers in comparison look like they are in a heart surgery suite, everything spotless and white. I am getting better though, especially after discovering that you don't need to cleanout the resin vat after each print session but can leave the resin in it for days or weeks as long as it is covered. It was actually cleaning things out that was making a mess, eg slopping resin when trying to tip it back into the bottle.

I definitely wouldn't call myself an expert in any way, but the process of the actual printing is surprisingly easy so every user can look like one. You get a test file with the printer which is a kind of mesh cube tilted at an angle which is meant to test all the printers movements etc as it is printed and the process to get there is literally - unpack printer, level bed, pour in supplied resin, stick USB stick in and press print (File has all the settings already baked in) and 4 hours later you have a3D thing to hold in your hand! The main learning experience rests solely in getting the settings right and then learning about the best ways to orient the prints and when supports are required.

The real photon nerds hang out in a facebook group, unfortunately. I say unfortunately because instead of everything being in subjects like this forum so you can easily look up issues and so on, its just one long string of posts so if someone posts something of potential interest today, tomorrow its probably buried and lost 200 posts down the list, Unless I am using facebook wrong - its the first and only time I've ever been on there!
 https://www.facebook.com/groups/AnycubicPhoton/?ref=bookmarks

They do have some attached files with suggested printer settings for various resins etc which really help out, and also have a page of answers to the most common issues.


Hey Bill, as to your question about resin longevity, all I can say from my own experience is - everything is still good after 8 months! Seriously though there are a heap of resins available and currently being developed, some are really exciting such as clear ones and rubbery ones so you can print flexible tyres etc, or add it in various proportions to other resins to change the properties.  Again, the facebook group has all the resin info hidden there.


I'll try to get some photos and attach them over the next few days. ALso if anyone has a stl file of something they want to print to compare with shapeways etc, if they can get it to me I am happy to do it and post up pics. Has to be little though, resin is pretty expensive down here what with the Australia Tax we pay on everything for the privilege of living here.

In the mean time, this thread here on a model railway forum I'm on is a good intruduction and has pictures and questions and answers probably relevant to modellers:

https://www.rmweb.co.uk/community/index.php?/topic/142773-anycubic-photon-3d-dlp-printer/

[finescalerr]

Thank you for the answers and the links are excellent. Looks like this will be a very educational thread. -- Russ

[Chris J]

Although I'd been aware of 3D printing for a few years, two things had kept me away from dabbling in it – the quality of the output and the need to learn 3D modelling software. All 3D prints I'd seen had a rough gritty kind of look with very crude detail and 3D software appeared very daunting. The first of the two reasons disappeared about 12 months ago when I started to see output posted online produced on the Photon which seemed to meet my quality expectations given that I'd be using it for producing architectural details for 4mm and 7mm to the foot models.

Once the printer arrived I put off the learning 3D bit by trawling websites for free .stl files to print while I got more familiar with the dozens of 3D modelling packages out there. Doing this I stumbled upon the Scan the World website, a worldwide  project to scan the worlds artworks and cultural objects and make them available for download.

https://www.myminifactory.com/scantheworld/

At first glance I assumed there was some mysterious wealthy benefactor behind it all, maybe Charlies Angels style, with Charlie sending out teams of hotties with 3D scanners on scanning missions around the world. Once I got into it though I found it was community based whereby individuals can scan items and upload them. Again I'd just assumed that you required a 3D scanner for that purpose, something I'd thought of as a  "Maybe one day when they are cheaper" kind of thing but when I checked out the details of the uploaded files I found that many had been created with photogrammetry software, something I'd never heard of before. Now maybe I am the only one who has never heard of this before in which case this is all a bit redundant but for any others like me out there who might want to know more  continue reading.
If  you have a half decent camera and a half decent PC you can take a grid of photos of an object and the software will create a 3D model of it. Now there  are a number  of caveats – it won't work on reflective objects for instance but within the limitations  I've found it surprisingly good.

The one I've been using is 3Dflow Zephyr.  https://www.3dflow.net/3df-zephyr-pro-3d-models-from-photos/

There are 3 levels of licensing, a free version with the limitation that you can only process 50 photos, a licensed paid for copy with no limitations and a couple of extra options and the pro one, mainly aimed at satellite imagery and so on. I've got the paid for version but the free one would be sufficient for my needs.  You do need a pretty hefty PC/Laptop with  preferably an Nvidea graphics card since it uses that to offload some of the processing if you don't want the processing times to blow out to extremes.

Here's a youtube video that gives an overview of the process

https://www.youtube.com/watch?v=kdtLtBt9dJY

Not having any culturally significant art work in my area I settled on using  old headstones as my test subjects, since they are non-reflective and easily accessible. To my surprise I have found the process itself  strangely addicitive and my test subject count has blown out to around 260 different headstones processed with another dozen or so waiting processing, a new book purchased called "Field Guide To Sydney Cemeteries" and a list of five more cemeteries with interesting looking headstones  and statuary to visit in the near future. At some point I will have to stop considering myself as a railway modeller and more a monumental masonry modeller...

Included in the process between the photogrammetry output and holding a physical 3d model requires two other software packages, both also free – Flashprint to scale the model and Meshmixer for any editing that is required. I won't go in any depth here with these, this was just meant to be a mention of photogrammetery since I haven't seen it here in relation to 3D modelling before.

Ive attached some photos showing a typical project as an overview. The first is one of the original images that went into 3Dflow. The next 2 show 3D flow results after processing, then theres the resulting mesh  file combined and finally  the 3D print, with a quick and dirty  rough paint job just to compare to the original more easily.

Obviously it won't suit everyone and I'm not sure how 'scratchbuilt' a model made for it could be claimed to be but I'm thinking for smaller architectural details and scenic items at least it could be quite useful. More than happy to answer any more questions anyone might have.

[Chris J]

And heres the other pics in the process...

[Ray Dunakin]

That is amazing!

[SandiaPaul]

There is a giant 50+ page thread on this printer over at The Railwire if you want to drown in info:

https://www.therailwire.net/forum/index.php?topic=45736.0

[finescalerr]

I read about 25 pages about it over the weekend on a forum Chris linked to in his second post.

I also found a new, local, laser guy who does very clean, hi-res work. Please excuse the desaturated and distorted iPhone snapshot of his work. The parts will be for an On3 caboose.

Russ

[Chris J]

A couple more from my summer 2019 memorial collection, all created with the above process.

[finescalerr]

Impressive. -- Russ

[finescalerr]

Just for fun, here are some built-up 1:48 scale ratchet-pawl assemblies from yesterday's laser adventure. The material is 0.013-inch thick (100 lb.) Strathmore Bristol Smooth paper. They are tiny, especially the microscopic brake staff collar and the bolt on the pawl. -- Russ