First step is to download a slicer to convert your miniature files into a language your printer can understand. ChiTuBox is free and has been the most reliable in my experience.
Once your slicer is installed, you need to tell it which printer you are using and set your general settings. When you open the software, you will see a box marked Settings on the right hand side. Open it and choose the Add New Printer option. Once that is done, there are only two tabs here you really need to worry about – Print and Infill.
Infill is the simplest to set up. I set it to None and leave it be, as it gave me inconsistent printing when I hollowed larger miniatures.
Under the Print tab, you will need to change these based on the resin you are using. There are many resources online to get those settings, but it’s usually best to start with whatever the manufacturer of your resin recommends. The primary setting you will want to change is Layer Height.
The primary reason resin printers can print with such high detail is the ability to do so in very small layers. The most common layer height used is 0.05 mm, which is sufficient for the vast majority of prints. However, miniatures with fine details will benefit from a smaller layer height. You can go all the way down to 0.01, but it will drastically increase the print time. In my experience, I have found 0.03 to give the best results without taking several days for one print. If you find that tiny details like eyes, feathers or scars are obscured, you may want to try a lower layer height.
Exposure Bleed is another issue to consider when determining which layer height works for you.
Depending on the resin you are using, you will need to find the sweet spot for exposure time. You might be tempted to set this low, as it drastically speeds up print time. Resin shrinks while curing, however, so you need to find the sweet spot.
The vast majority of shrinkage happens during printing, but if your exposure times are too short some of that shrinkage will happen in post cure. Post cure shrinkage puts undue stress on the model, which can lead to cracking. If you set it too high, your exposure bleed will increase, resulting in prints with visible layer lines. Experimentation is the best way to find the best settings, but asking experienced printers what settings work best for them can be quicker.
You will probably hear discussion of “Magic Numbers”, which are important when using FDM printers. Resin printers still have those numbers, but they mean very little. Most resin printers use standard stepper motors with 200 steps per rotation and a single start lead screw with a 2 mm pitch. If we divide 2 mm by 200 steps, we get a “magic number” of 0.01 mm. Optimally, you would want to set your layer height to any increment of 0.01 mm to avoid layer inconsistency. That being said, the UV light will cure the entire layer regardless if it’s a microstep off.
Orientation & Support Placement
Orientation of your model is important, as you want to avoid long overhangs that might droop or unsupported islands that will leave cured resin bits floating in your vat. Understanding islands is best left to YouTube videos, as a visual aid is definitely needed to get a firm grasp. Here is a link to a great video explaining what islands are and how to deal with them: 3DPrintFarm
Beyond those tutorials on understanding why supports are necessary, I try to orient my miniatures in a way that the supports will be the easiest to clean up. It’s much easier to level off a flat area, or reshape a large section, than it is to carve in lost detail.
The image on the left is a standard dual-wielding barbarian on a horse. Not a particularly challenging print, but still a few things to keep in mind.
- The bottom of the shield is very close to the saddle, making it nearly impossible to add a support.
- Fine details, such as the braided beard and buckle under the horse would need to be supported, but adding a support would destroy the detail.
Both of these issues can be solved by simply printing the model upside down. Now the gap between the shield and the saddle is no longer an issue, as the shield is supported elsewhere. The beard no longer needs supports, because it’s printing straight up.
You will have the problem of needing to support the ears of the horse, but that is easily fixed after curing with a needle file. In this orientation, none of the details that would be ruined by supports will need them. The beard, the buckle under the horse, the studs on the shield, facial features of the Barbarian – all are support free and will print perfectly.
Supports will be needed on the horse’s mane, ears, and tail. The Barbarian will need multiple supports on each hammer and one or two supports on his bald head, and a few supports under the shield. All of these are easily filed off for a perfect miniature.
Alternatively, there is another option for those that might have trouble spotting those islands. This method isn’t my preference in general, but it’s great for models with a LOT of tiny details that need supported. Rather than go into detail here, I will include a video from 3D Printed Tabletop on YouTube.
Hollowing & Drainage Holes
Miniatures don’t need to be hollowed, but some bulky miniatures (Giants, Ogres, Etc) can use up a lot of resin if printed solid. I hollow mine with 2mm walls, as that is about the depth UVA can penetrate opaque resin easily and allow for even curing. If you print large miniatures solid with opaque resin, you will find that the resin can slowly seep out of the print and ruin your paint. If you use a translucent or transparent resin, the UVA can penetrate much deeper, so I would suggest using such resins for large solid models.
Once you have your miniature hollowed out, you will need to add drainage holes to remove the uncured resin from inside. I try to place these holes in areas where two pieces will be glued together or on the bottom of the model where they won’t be seen. Create two or more holes to allow cleaner to flow through the model. A single hole will take much longer to drain and fill. If there are no hidden areas to add holes, I try to put them on larger areas with less detail, so I can fill them with Plastic Putty later. Alternatively, you can simply use a pin vice and drill bit to make holes where you want them after the fact.
These are the support settings I use and very rarely have a failure. When I do have failures, it’s almost always caused by rushing through the process and missing something. You can give my settings a try or develop your own.
Below, I have listed two sets of settings for Heavy and Medium. I have best results mixing the two based on what I’m supporting. Use a few Heavy supports on bases or in areas where the support will be holding up a large island before it connects to the rest of the model. Use medium supports on the small sections that just need a little help. This makes it much easier to remove the supports without damaging the miniature.
As you can see in the sample above, the base is supported by heavy supports to ensure they don’t disconnect when pulling away from the FEP. Since they are located on the base, they will be easy to remove and file down.
Medium supports are used on the rest of the miniature. They look fairly large in the scale of Chitubox, but on the printed miniature they are tiny and simple to remove.