Why My Support Structures are partly missing or broken in SLA/DLP/LCD 3D Printing?
Adding support is always a headache when it comes to Stereolithography SLA/DLP/LCD 3D printing. A lot of times, there will be problems about support structures appearing in the 3D printing process more or less. A typical situation is that parts of the support structured are missing or even broken. How to solve this situation?
Most of the time, the missing or broken support structures are caused by improper parameters, mainly related to those following parameters.
Contact Depth of Top
The deeper the contact depth, the deeper the support tip inserts into the model. We need to confirm that the contact depth is deep enough to win the tug of war between the build plate and the FEP film in the bottom of the vat.
With luck, it may result in deformation or misrun in the joint part between 3D model and the broken supports. If you are unlucky, there is only the raft/bottom and support structures on the build plate while the model is not printed successfully at all. Also note that this operation will also leave more visible marks after removal.
The upper/lower diameter is like the "joint" of the support structures. If the joint is not well connected, it is prone to "fracture". Usually, the thicker the upper/lower diameter, the stronger the support is. It's helpful to reasonably adjust the upper/lower diameter to avoid that the middle part can’t afford the heavy top.
Diameter of Middle
As the "spine" of the support, when the diameter of the middle increases, the support is rougher. Obviously, if the "spine" is too thin, it will be easily broken or missing. Also you need to pay attention to the middle and the top in perfect proportion and harmony.
The support structures are also affected by the light power and the curing or exposure time. Exposure Time is the amount of time that the light source will expose each layer during printing. Different SLA/DLP/LCD 3D printers have different cure times for resins. However, the exposure time is not the more, the better. Excessive exposure will make the layers thicker than expected, resulting in distortion or even transformation.
In addition, besides parameter problems, the missing or broken support structures may also be affected by the 3D printing machine, such as insufficient light source, dirty FEP film, LED panel defects, etc.
To solve the problem of support missing or broken, we need to customize the printer and set the above parameters reasonably as well as add interconnected supports to increase the success rate of printing. When generating supports, it’s better to bridge supports together instead of placing them individually. In CHITUBOX, interconnected supports greatly reduces the chance of support deformation. This design allows the support structures to be held together more firmly, making it less vulnerable to failure. Even if some parts are missing or broken, other interconnected parts may play a supporting role and greatly improve the success rate of printing.
Model source: https://www.thingiverse.com/thing:3306294