How to 3D Print with Resin: A Step by Step Guide

Curtis Satterfield, Ph.D.

Curtis Satterfield, Ph.D.

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In this article I am going to walk you through resin printing a 3D model step by step. I will show you and discuss all the important steps in detail.

In order to 3D print a resin model follow the steps below:

  1. Create or Download a Model to Print
  2. Use a Slicer to Prepare your Model
  3. Copy your Sliced File to the Printer
  4. Prepare the Printer
  5. Print your Model
  6. Remove the Model from the Build Plate
  7. Wash Your Print
  8. Remove Support Structures from Your Print
  9. Cure Your Print

In this guide I will walk you through the step by step process of obtaining, preparing, and printing a 3D object. For the article I will be using a tabletop miniature model to demonstrate prints that require supports and I will use a simple XYZ calibration cube to print an object with no supports.

For this guide I am assuming that you have access to a resin 3D printer and a computer in order to complete the steps. If you are reading this guide and haven’t yet decided on a 3D printer, I will link to recommendations for resin printers in the article. So, let’s get started!

Create or Download a Model to Print

The first step to 3D printing is having something to print. You can create your own models using software like Blender or AutoDesk Fusion360 or you can download premade models from the Internet. Today I’m being lazy and downloading some files for us to print!

The first model we will be printing today is a simple XYZ calibration cube that can be used to tune FDM printers. Why are we printing this on a resin printer? Because using the XYZ cube will allow us to print a simple geometric shape and examine the process of hollowing a model in resin printing. I want to use a simple model and a more complex model in this guide, so a 3D calibration cube fits the bill.

I will be using this XYZ cube from iDig3Dprinting on Thingiverse. The model is a simple 20 x 20 x20mm cube with the sides labelled to make measurements for calibration easier. If you are curious how this cube is used to calibrate FDM printers go read my guide about FDM printer calibration.

XYZ Calibration cube for 3D printer

3D Calibration Cube from Thingiverse. Source – iDig3DPrinting on Thingiverse

For the second model I will use a tabletop gaming miniature to demonstrate the use of supports in models. I will be using a Female dwarf warrior model by PollyGrimm on Thingiverse. This model looks great with a ton of detail and will require us to use supports.

Female Dwarf Warrior 3D Model

As I mentioned before you can also create your own models to 3D print using software such as Blender for models like our Dwarf above or Fusion360 for models such as the XYZ cube. Using that software is beyond the scope of this article so we will stick with downloading our models.

Ok. First step is to download the models. Find a model you want to print and download the corresponding files. On Thingiverse simply click the “Download All Files” button and you will download a zip file that contains the SLT files, images of the model, license and readme files. Below you can see the files I’ve extracted from the downloaded zip.

Extracted download of 3D Model files from Thingiverse
 

The files we need to print are in the “files” folder. Be sure that you extract your files to an easy to remember location on your computer. Now open the files folder to see the STL files. In the image below you can see one of my favorite 3D applications in action. Papa’s Best STL Thumbnail viewer. This windows extension generates a view of all STL files on windows to make looking through your STL files easier. I highly recommend downloading and installing it! You can download it here.

3D printable Female warrior stl viewed with papas best thumbnails

 

 I simply repeated the same process to download and extract the XYZ cube. Now we have our models saved to our computer so step one is complete. Next, we need to prepare it for 3D printing. For that we need to fire up our slicer which we will cover in the next section.

Use a Slicer to Prepare Your Model

First, let’s talk about slicing programs and why you need to use one for 3D printing. When you download or create a 3D model for printing it is stored in a common 3D file format such as an STL or OBJ file. These files allow your computer to read and interpret the information in the file to display the object on your computer screen. However, your 3D printer doesn’t understand how to turn the data from an STL file into a 3D printed object. For that you need to use a slicer to convert the information in your STL file into information readable by your resin printer.

Once the file has been generated by your slicer you can transfer it to your 3D printer and begin printing. That is the most basic assessment of what a slicer does and why you need it for 3D printing.

For resin printing we need to use a slicer designed for resin printing. We need G-Code commands that send images to an LCD screen and tell the printer how to turn the light on and off and how quickly or slowly to raise and lower the build plate. For this process we will use ChituBox which is a free slicing program. You can download ChituBox here.

Open ChituBox and import your model for printing. To save time and wear on my LCD screen I will be printing both models at the same time. But I will review how to prepare them one at a time. We will start by importing the XYZ cube and preparing it.

In ChituBox click the hamburger menu and select Open…

Open Files menu selected in ChituBox
Navigate to the file you want to import, select it, and click Open. ChituBox will place the model in the center of the build plate. Note, that if you import several models at once they will all be placed overlapping on the center of the build plate. To organize them click the auto layout button in the menu bar.
 

Now our XYZ cube is imported and on the build plate.

XYZ cube 3d printer calibration model imported in ChituBox
For the XYZ print I will be printing it flat on the build plate to demonstrate a print without supports. This method isn’t recommended for most prints as it can create issues. However, for our guide today it won’t be an issue.

Be careful when placing your models in ChituBox. If you end up moving the model off the build plate and slice it, your print will fail. If the model is sitting a few millimeters above the build plate in the slicer the printer will try to print it that way. You will end up with a mess in your resin vat that you need to clean up.

While I won’t be using supports, I will hollow out the model in order to use less resin. The downside to hollowing the model is that I will need to add drain holes to the model. If you create a hollow model and don’t make a way for the resin to escape, the uncured resin will eventually leak out of your model causing it to crack and split. The drain holes are a necessary evil for saving resin. If you are printing a highly detailed model, you may want to use the extra resin to avoid drain holes.

First, we need to hollow out our model by clicking on the Hollow button in ChituBox.

The hollow button in ChituBox
Set the desired wall thickness, the thicker the wall the stronger the print, but the more resin it will use. I will leave it at the default 1.2mm thickness. Click Start to hollow the model.

ChituBox will hollow the model and now if you drag the layer slider down you will see that the model has been hollowed out.

Hollowed cube cross section in ChituBox
It is always good to use the layer sliders and inspect what the hollowed model looks like. On complex models you may find that you need to thin your walls down for the model to be hollowed properly.

With the model hollowed we can move on to adding our drain holes.

We need to add holes at the bottom of the model and near the top. If we only add holes at the bottom the suction force of the resin will cause it to stay in the model and not drain out as expected. Drains holes also allow resin that is pushed up into the model during the print to flow back out.

 

To get started, click the Dig Hole button in ChituBox.

Dig Hole Button in Chitubox
The default setting is 2.0mm for the hole size but I find that 2mm can be too restrictive. Since I’m not worried about the surface finish of the cube, I set the size to 4mm. The cube is 20mm on all sides so I am not worried about drilling all the way through the model and can leave Depth set to 8mm. If you are trying to hollow a complex model, you may want to reduce the hole depth or you will end up digging a hole straight through the model.
 

Placing your mouse over the model will show a green cylinder where the hole will be dug.

Dig hole position in Chitubox
You want to place the holes in areas that are either inconspicuous or easy to repair. For the cube I don’t care about the looks so I will drill two holes on the top and four holes around the bottom.

 

A really important point to note is that the top of the model in ChituBox will be the bottom of the model while printing. The build plate is lowered down into the resin and the print hangs off the plate during printing. Always think about the printing orientation of the model when drilling drain holes!

Hollowed model with holes dug in Chitubox
ChituBox will take the part of the model it drilled and place it on the bed plate. If you leave them to print you can use them to fill the holes back in after curing. However, I’m not worried about looks and to save resin I will be removing all the hole plugs. Be careful when digging holes. If you click to close to the edge of the model you will get an error and won’t be able to create a hole. If you get the error, try moving the hole away from the edge of the model.
 

Ok, our XYZ cube is done and ready to go. I’m going to move it off to the side for now and work on preparing the miniature.

XYZ 3D printer calibration cube ready to go in Chitubox

Same process as before to open and import the model into ChituBox. Once the model is imported, we can begin preparing.

Female Dwarf 3D model imported into ChituBox
We need to orient and tilt the model to prepare it for supports.

There are many schools of thought on the best way to position and support miniatures. The main idea is that we want to avoid supports on the highly detailed areas. When removing supports from the print, inevitably you will have some damage. You don’t want to orient the front of the model facing down towards the build plate. Some people will simply lay the model on its back and support it in that orientation. The benefit to this approach is that you have fewer layers to print so the print takes less time. However, you end up with a lot more supports and areas that can be damaged from support removal.

My preference is to print the model upright tilted backwards around 15-20 degrees. This puts most of the supports on points under the model that won’t be as noticeable.

Dwarf 3D model tilted 15 degrees back in Chitubox ready for supporting
Now comes the tedious part, we need to add supports to the model. Supports server two purposes, to anchor the print to the build plate, and to connect any “islands” until they are joined to the model. You may be tempted to use the auto support feature to save time. Don’t do it! Auto supports will often end up with failed prints and you’ll waste more time and resin using them than if you do the supports manually.

Learning to manually support your models will take some time and effort but will be worth it for beautiful prints. You want to aim for the least amount of supports on your model that will still provide the structure needed for a successful print. Learning how to support models is a bit of an art form in addition to a science. I will demonstrate how I support the model for this guide, but it is not a thorough explanation of why I placed all the supports where I did. It is meant as a guide to get you started.

To begin you need to identify where supports are needed in your print. The easiest method in ChituBox is to look up through the build plate at the bottom of your print. Make sure you are on the supports tab as shown below.

Supports Tab in ChituBox

Now if you rotate your build plate view so that you are looking up through the build plate you will see areas of red on your model. Right click and drag around the build plate to rotate it in ChituBox.

Missing support areas highlighted red in Chitubox

Slowly drag your cursor up and you will see a line pass through the model. Look for the first points where the black line appears on the model. Those will be the places you want to anchor the model with heavy supports. ChituBox also suggests areas where there are islands. You can see small gray lines in the image above at various points on the model. These lines indicate areas with islands that need support

But don’t be complacent, ChituBox doesn’t always define all the islands, and you will need more supports to have a successful print.

First area of contact for support anchors in Chitubox

In the above image we can see the point of the model closest to the build plate. We want to start adding anchors in these areas to connect the model to the build plate.

Continue adding supports to the model using heavy for anchor points where the most force will be applied as the model prints. Because we are connecting to places that will have the least visual impact, don’t hold back on using the heavy supports. You want to ensure that your print will be anchored well and won’t fail while printing. Once you’ve got the model well anchored switch to medium and light to connect any small islands.

Island that needs support structure in Chitubox

Circled in yellow is an example of an island that needs support.

Islands are areas that are not connected to the current model and would print with nothing to connect with. Be sure to use supports to connect all the islands you find as you slowly drag the cursor up the model. Rotate the model and look for islands from many different angles.

When placing supports be sure support pillars are not too close to the model. Due to light leak from the LCD screen and inconsistencies during the print process your support may end up bonded to the model.

Supports too close to model in Chitubox

In the above image the red support is really close to the model. To avoid issues, use the edit support tool to move the support pillar away from the model.

After several minutes of examining the model and placing supports it’s ready to go.

3D dwarf miniature model supported in ChituBox
Most of our supports are on the underside of the model where damage from removal won’t be as evident. We’ve also created a nice solid base for the print to stick to the build plate.

Both the cube and our miniature are ready to print so I will arrange them on the build plate.

3D Models ready for slicing in ChituBox

Now it’s time to check our slicer settings before slicing the model.

Click the gear icon tab at the top left of ChituBox and then click Settings.

Settings button ChituBox

Your printer settings should be already configured from adding your Printer to ChituBox. The tab we are interested in is the print tab.

ChituBox print settings

The important settings here is the layer height. The exposure settings are dictated by the resin you are using. I highly encourage you to calibrate your resin with a test print to dial in the exposure. I covered how to do this in my guide to printing miniatures on a resin printer.

A layer height of .05 gives us a good balance of quality and printing speed. I encourage you to test print the same model at both .05 and .025 and see which you prefer. When lowering the layer height be sure to adjust your exposure accordingly. A good guideline is to reduce your exposure time by 25% if you reduce the layer height by half. Going from .05 to .025 reduce your exposure by 25%.

I’m happy with .05mm layer height for my prints today so I will stick with that. All the other numbers are calibrated to my printer and resin. After you have entered the appropriate settings on the print tab, click the X to close it.

Now on the main ChituBox Screen click Slice

Slice button ChituBox

ChituBox will now slice your models, this can take several minutes depending on the complexity of the model. Once done you will see the following screen:

Sliced models ready to save in Chitubox

Now click save to save the sliced file to your hard drive.

The file will be saved to your hard drive in the specified location. Once it finishes saving, click open the folder.

Sliced 3D model successfully saved to disk and ready to print Write successful Chitubox

Now you’re ready for the next step.

Copy Your Sliced File to the Printer

You will need to get the sliced file you created in the previous section onto the printer for printing. Your printer may use an SD card or a USB stick to read from. Simply copy the sliced file from your computer onto the memory card you use in your printer. Now take the drive and plug it into the printer.

That was an easy step.

Prepare the Printer

To prepare your resin printer you need to:

  1. Ensure the printer is level (only if first setting up or you just moved the printer)
  2. Ensure the build plate is clean
  3. Ensure the resin vat is installed properly
  4. Fill the vat with resin ( I recommend something like Elegoo standard Grey Resin)
  5. Wait for the resin to settle and the bubbles to pop
  6. Ready to go!

Put on your respirator and nitrile gloves! Resin is toxic and you don’t want to breath it or get it on your skin!

Your printer needs to be level so that the resin in your vat is level to the build plate. This only needs to be done when you are first setting up your printer or you’ve moved the printer. If you’ve bumped or moved the printer accidentally it doesn’t hurt to check. Grab a level and place it on top tour printer. Make sure that it is level from side to side and from front to back. Use the adjustable feet on your printer to level it properly.

Make sure your build plate is clean! I thoroughly clean the build plate after each print, so it is ready to go for the next print. It is always a good idea to check and make sure the plate is clean. Dirt and residue can cause your prints to fail.

Make sure the resin vat is seated correctly in the resin printer and that the screws holding it down are tight.

Fill your vat with resin. In the picture below I am using Elegoo Standard Grey Resin (Amazon Link) Some vats will have an indicator of minimum and maximum fill but not always. Refer to your printer’s documentation to ensure you have added enough resin. SHAKE YOUR RESIN bottle before pouring into the vat! Resin will settle out and you need to be sure that it is thoroughly mixed before pouring!

Filling a resin 3D printer's vat with resin

After pouring resin into the vat it will be loaded with bubbles from the vigorous shake you gave it. You did shake your resin, right? You need to let it sit long enough for the bubble to dissipate. I find that around 30 minutes does the trick.

3D Printer resin vat full of bubbles after filling

After waiting for the resin to settle you should have a nice smooth surface on the resin and be ready to print!

Elegoo Mars 3D printer ready to print

Print Your Model

Turn on your printer and locate your model. Your printer may vary on how to start a print. I will list the steps using my Elegoo Mars

Elegoo Mars resin 3D printer main menu

On the Elegoo Mars press the Print button to open the files on your USB drive.

Select the file you want to print.

Elegoo Mars 3D resin printer print file selected

On the following screen press the play button to start the print.

Elegoo Mars 3D resin printer menu print ready to start

The build plate will lower, and the printer will begin the printing process. The printer should also show you the estimated time remaining on the print. Set a timer and go do something else because this is going to take several hours.

Remove the Model from the Build Plate

Finally! The print is done! Now we get to take it off the build plate and prepare it for washing and curing. Here is a little trick I learned a couple years ago for removing prints from the build plate. Take a pair of flush cutters an “snip” under the edge of the print between it and the build plate. In many cases this will cause the print to pop right off. If not, it should at least give you clearance to get a plastic scraper underneath to finish separating the model from the plate.

Carefully place the flush cutters under the corner of the print.

Easily removing 3D resin print from build plate with flush cutters

After squeezing the flush cutters closed the print should pop right up. 

The next step is to wash your prints.

Wash Your Print

We need to remove the excess resin that is still clinging to the print. I have an ANYCUBIC Wash and Cure (Amazon Link) that I love so that is what I used. You can read about the Wash and Cure on my review here. I also have a plastic pickle serving jar (Amazon Link) that I used before getting the wash and cure so you can use something like that if you are just getting started. Either way the print needs to be washed. I use Mean Green cleaning solution (Amazon Link) instead of isopropyl alcohol as it’s cheaper and works well for me. If you are using Mean Green in your Wash and Cure DO NOT leave it in the basket. It will strip the grease from the impeller bearing over time!

Into the wash basket.

3d printed resin models in Anycubic Wash and Cure wash basket

And cycled twice at 6 minutes each.

3D printed resin models in Anycubic Wash and Cure

After the wash cycle the prints still have Mean Green on them so I will rinse them with hot water and give them a light scrub with a toothbrush. I will also remove supports at that time.

3D resin prints post wash

Remove Support Structures from Your Print

I prefer to remove the support structures after washing but before curing. With the right support settings and the warm water, the supports pop right off with almost no damage. If you’d like to learn more about removing supports read my article on removing supports from a resin print here.

Gently remove the supports from your models and give them a light scrub with a toothbrush. Let them air dry before curing to avoid white residue on your cured prints. Now they are ready to be cured.

Cure Your Print

The last step! Now that your prints have been washed and air dried, we can cure them. Once again, I will be using my wash and cure. If you don’t have a wash and cure you just need a UV light source that has a 405 nano meter light output. Something as simple as this UV nail dryer (Amazon Link) will do the trick!

Here are the prints on the turntable ready to be cured.

3D resin prints on cure plate of Anycubic Wash and Cure

I did two cure cycles of 6 minutes.

3D resin prints being cured in Anycubic Wash and Cure

And now the moment we’ve been waiting for. Time to finally see what our prints look like after curing!

3D resin prints post cure

 

Remember what I said about waiting for the prints to air dry? Well, I didn’t, I was in a rush and the result is the white residue on the cured prints. Not a big deal though. With a little primer and paint on the miniature you won’t see the discoloration anymore!

So, there you have it, how to do a resin print from start to finish! If you’re interested in purchasing your own resin printer after reading my guide, head over to my recommended resin printers page. I hope you found this article helpful