Photocentric UV resin compatibility guide
Our high-performance resins have been formulated to be compatible with a wide range of 3rd party 385nm or 405nm 3D printers. To review the available resins, please visit our materials page
UV Resin Layer Exposure
Overview
This guide will assist you in establishing a layer exposure time for a desired resin and layer thickness based on the characteristics of Photocentric’s UV Resin range and your UV 3D printer.
Each resin requires a specific energy to cure a certain layer thickness. ‘Energy’ is defined by multiplying ‘light output intensity’ of your printer and a ‘given time of exposure’. The equation below simply explains the matter:
Energy [mJ/cm²]= Light Output Intensity [mW/cm²] x Exposure Time [s]
Your UV 3D printer manufacturer will provide you with light output intensity value.
Example
For this example, we will look to establish the exposure time for a 100 µm layer with Durable UV80. The energy required for this is 12.1 mJ/cm². and the chosen UV 3D printer has a light output intensity of 6.2 mW/cm².
So, to calculate the exposure time, divide the Energy by the light output intensity:
12.1 ÷ 6.2 ≈ 2.0 s
Information on required energy for Photocentric’s UV Resin range can be found here >
Post Processing
All printed parts will need to be exposed to UV light to obtain the mechanical properties found in the technical data sheet for that material. Some resins require difference post exposures therefore please refer to individual technical data sheets for post processing instructions which can be found here >
How to achieve a crystal clear finish with Durable UV SuperClear?
For a Matt effect, parts can be finished with wet sanding to achieve a smooth surface. It is recommended to start sanding the clear post-cured parts with 320-360 grit sandpaper to remove layer lines from the print process, moving to higher grit sandpaper for polishing. A suitable polishing compound can also be used. Care should be taken to determine not to over-polish, which may result in a glossier finish. Once the surface is ready, the part should be cleaned well with soap and water and fully dried to reveal a frosted glass-like appearance.
For a Gloss effect, parts can be finished with wet sanding to achieve a very smooth surface. It is recommended to start sanding the clear post-cured parts with 320-360 grit sandpaper to remove layer lines from the print process, moving to higher grit sandpaper for polishing. A suitable polishing compound can also be used. Once the surface is as smooth as desired, the part should be cleaned well with soap and water and fully dried. An appropriate gloss clear acrylic spray lacquer can then be applied to reveal a glass-like finish.
Print Troubleshooting
Casting Issues
If you are having issues casting using the castable resins please refer to the instructions here.
Holes appearing in the side of prints
Holes in the sides are often caused by blowouts due to air cupping. This is caused by either hollow parts or parts where a large air gap is present in the print and there is no air gap for the air to release through. Please refer to hollowing prints below for more information if you are still experiencing difficulties.
Hollowing Prints
It is possible to hollow out prints using software such as Meshmixer or Tinkercad but this can also be done using Photocentric Studio. Always keep in mind that there needs to be drain holes to allow the flow of air throughout any hollow structure. It will form a cupping effect if the air has nowhere to go which leads to failures in the prints called “blowouts”. Adding an air release hole into a print will help stop this.
Platform adhesion issues
If the print is removing itself from the print bed and remaining within the vat after a print, try increasing the base layer time (also known as the burn in time). This will aid in forming a strong bond between parts and the build platform.
If you are experiencing adhesion issues on a Formlabs printer, try reducing the platform z height by following the instructions found on Formlabs website here
Lack of details on prints
If you are finding that your prints are not coming out as well defined when using our resin, it is possible that the cure time you are using is incorrect. Try printing using our test piece here using your time. If the text is coming out very thin and there are many poles missing, increase the cure time and print again. If the text is coming out thick and blurred, all the poles are present but a large number of holes are filled in, the cure time is too high. Try reducing it.
My printer doesn’t have variable settings
When settings on the printer can’t be varied, we advise using the standard settings that the printer comes with such as the Clear and Black settings on the Formlabs printers.
Print failing on supports
It is important to ensure that enough supports are being used to print your part. Try increasing the number of the supports and the diameter of the poles. If they are still breaking around the point that connects the support to part, try increasing tip diameter. Certain resins, such as Flexible and Ultraflex, will need larger supports diameters and tip size due to the lower strength in the green state.
Prints cracking
Parts can crack if not enough supports are added to the part. Increase the number of supports to avoid the parts from moving too much during the print and stop cracks.