How to set up proper SLA resin supports for a successful resin print.

Index

Setting Up Support Settings

In today’s article, we will focus on customizing our settings to get the best results from our resin prints.

Orientation, size and surface area all play an important role in a successful print, but each of these often depend on the type of model you have and the resin being used. It’s very important to first establish proper exposure settings for the machine, since this affect the results of the calibration. I personally prefer to use Photonsters Validation Matrix 2 for my preliminary calibration, and I will include a link in the description below. It prints quite quickly and allows me to get results fast. If at all possible, it’s generally recommended to print with a colour that’s easily readable, since this makes it easy to gage the results. I generally always start with the manufacturer’s recommended settings, then incrementally increase these or decrease them until these two points are just barely touching. I will also aim to make sure that as many of these lines are printed as possible.

Some slicer’s offer a variety of saved settings for different use cases, and these will be important to set up properly before even adding them to your model. In Chitubox for instance, you can choose between your light, medium and heavy supports and these can vary quite a bit depending on the use case. In order to determine what settings to actually use, especially for the model contact points, you could do it the long way or use a model that’s similar to Amerlabs. This model is great for figuring out the support thickness for the smallest of supports, as well as their connection lengths. Amerlabs has included a great guide on how to use their calibration test, so I’ll include this link as well. Once you’ve figured out which dimensions worked best for your specific resin. You can then begin creating your custom support settings. Seeing as the most difficult settings tend to be for small miniatures, we’re going to focus on these for now.

To start things off, we’ll adjust the bottom exposure number, since this is quite often is too high. I’ve found that in most cases I only need to have one to two bottom layers, so long as I increase the bottom layer exposure time. To find out what this should be set to, you’re going to refer to that initial test where you printed the validation matrix. I normally add between 5 and 10 seconds to this initial bottom exposure time to help ensure proper adhesion. For the medium and heavy support settings, I’ll normally go with the standard recommendations since they require more rigidity.

We’re then going to take the number for the layer height and use this to calculate the platform touch shape thickness. For small prints this normally only needs to be a 1 layer, but for larger one’s I’ll use 2 to 3 times that initial thickness (layer height x bottom layer count). Generally, the heavier the support that I need, the thicker I’ll make this, so it remains rigid enough not to bend or break. You can see in this example the differences between my different types of support.

The connection point’s Upper diameter will depend on the results of the Amerlab’s test. I normally go slightly higher than the first successful pillar dimension, which is between 0.1 to 0.5 mm. The lower diameter for the connection point will be the same as the thickness of the pillar, however some users choose to reduce this number. I normally set the connection length just under the first successful test, just to be safe.

The pillar shapes have to support the model and remain rigid enough not to flex while printing, so in this case I normally air on the side of caution. I normally go slightly above double the thickness when compared to the “Upper diameter”. This helps ensure that the pillar will have a lower likelihood of flexing during the raising and lowering of the build plate. When setting up my heavy supports, I’ll set these fairly large, since I normally use those when I’m printing props. Models such as those tend to be quite heavy, and the last thing I want is for a print to fail or fall off.

When using automated supports, I’ll normally have these set to above 90% with an angle percentage of 35%. With the basic settings for your supports, it’s now time to implement these with your first prints, and you can see that process here.

Links to Calibration Files

Resources

SLA Printer Full Guide

How it all Works

If you’re new or interesting in starting 3D printing, you’ve probably heard that you needed to support your resins prints. But what is this, and how is it important? Today’s we’ll explain this core principle along with how it all works.

Resin prints are created using multiple layers of exposed resin and while this process can be relatively fast when compared to other’s, it does have some important considerations. Everything needs to be connected to the build plate in order for a successfully 3D print to occur. This is mainly due to the fact that the resin is only partially cured, requiring it to be attached to the remaining structure to prevent it from becoming stuck to the FEP sheet or floating freely within the vat. These stuck portions and floating particles can cause serious damage to the LCD screen if not taken care of. In a lot of cases, this will require their removal prior to continuing onto the next print, which results in lost resin as well as time.

Any portions of the print which aren’t connected to the remaining print structure or build plate are known as Islands. Examples of this can be clearly seen in the photon validator or on the layer preview for Chitubox. In this case, I’m showing you a supported and unsupported version, so you can get a better idea of what to look for.

When a print is completed, the material is only partially cured to ensure that all the details are present and not washed out from overexposure. This will often mean that it’s more flexible, therefore these regions need more support to prevent them from flexing or distorting. Portions which hang or extend outwards are known as overhangs. Take special care when dealing with these regions, since they will often need quite a few supports to ensure that the structure prints properly.

Another big consideration is that the print needs enough supports to keep it attached to the build plate. The main reason for this is that a large amount of suction is created when the FEP sheet separates from the build plate. My video on “How an SLA printer works” goes through this in more detail, but you need to know that adding supports is intended to overcome those forces. How a user orients their print, will often affect how many supports are needed, as well as the amount of suction that created within regions of the prints. In these two examples, there’s a large amount of suction created on one version while the second one has a lot less, which is due to their orientations.

The weight of the printed object will also contribute to the number and type of supports which are needed for a given 3d print. Since prints are done upside down, they have to contend with gravity as much as they do with the suction forces. This is often the leading reason why a print will be hallowed out prior to being sent to the printer. By removing any excessive or unwanted resin in the printing process, a user can save on material while maintaining great overall results.

Now that you understand the importance of supports in resin printing, we’ll go over how to set up basic supports.

Important Notes

  • Overhangs
  • Islands
  • Orientation
  • Weight

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