Recommended Printing Parameters: Exposure Time, Lifting Height, & Lifting Speed2017-06-28T04:10:38+00:00

Recommended Printing Parameters: Exposure Time, Lifting Height, & Lifting Speed

Exposure Time Scale

Table 1: XY Resolution Conversion to Projected Area (with the projector)

XY ResolutionProjected Width (mm)Projected Length (mm)Projected Area (mm squared)*Scaling Factor for Exposure Time
26 microns2849.81,393.70.5
37 microns4071.12,844.41
50 microns54965,1841.8
75 microns8114411,6644.1
100 microns10819220,7367.3
* Exposure time is proportional to the projected area for the same layer thickness.
* You may need to increase the exposure time as your light bulb is aging.
* The normal exposure time for Optoma projectors is about twice the time listed here
* For pigmented resins with high viscosity or sitting for a long period of time, please shake them for at least one minute before printing.

Table 2: Suggested Exposure Time (in seconds) for Spot-HT Resin

Z Layer Thickness (in microns)
25 microns35 microns50 microns
37 microns0.711.5
XY Resolution (in microns)50 microns1.423
75 microns2.846

Table 3: Suggested Exposure Time (in seconds) for Spot-E Resin

Z Layer Thickness (in microns)
50 microns100 microns
37 microns2.43.0
XY Resolution (in microns)50 microns4.45.4
75 microns9.912.1
100 microns17.521.6

Table 4: Suggested Exposure Time (in seconds) for Spot S-PRO Resin

Z Layer Thickness (in microns)
30 microns50 microns75 microns100 microns
37 microns0.711.52
XY Resolution (in microns)50 microns1.4234
75 microns34.568
100 microns6.591215

Table 5: Suggested Exposure Time (in seconds) for 3DSR General (Black) Resin

Z Layer Thickness (in microns)
30 microns50 microns75 microns100 microns
37 microns0.611.52
XY Resolution (in microns)50 microns1.2234
75 microns2.5467.5
100 microns591215

Table 6: Suggested Exposure Time (in seconds) for 3DSR Cast Resin

Z Layer Thickness (in microns)
30 microns50 microns75 microns100 microns
37 microns44.268
XY Resolution (in microns)50 microns681115
75 microns10152025
100 microns16304050

Table 7: Suggested Exposure Time (in seconds) for 3DSR DX Resin

Z Layer Thickness (in microns)
15 microns25 microns50 microns75 microns100 microns
37 / 38 microns11234
XY Resolution (in microns)50 microns1.524610
75 microns2481012
100 microns48152025

These are the recommended base line exposure times. In general, the actual exposure time needed should be lower than these numbers. Each print requires a customized set of printing parameters. We normally define parameters for 5 printing zones in the “basic mode” of our software.

  1. First zone: First layer only.
    This layer is called attachment layer which is part of the base and is the most important layer. The exposure time for the first layer is at least 10 times the regular exposure time to make sure that any potential gap between the build platform and vat floor is fully cured and the first layer is attached to the platform firmly. The lifting height should be set to 7 mm when using the large build platform and 5 mm lifting height when using the small build platform, with a lifting speed of 10 mm/min.
  2. Second zone: Rest of the base layers.
    Normally, the base layers are before layers for supports. The total thickness of base should be about 0.3 mm. The exposure time for this zone is half of the exposure time for the first layer. The number of layers in this zone depends on the thickness of the layers. For example, if the base is 0.3mm and the layer thickness is 0.05mm then you have 5 or 6 layers for the base. The first layer is for attachment and the rest is specified in the second zone. The lifting height should be set to 7mm using the large build platform and 5mm using the small build platform, with a lifting speed of 10 mm/min.
  3. Third zone:
    Rest of the layers that make up the first 2 mm of a model using large platform or the first 1 mm using small platform under the influence of the vacuum force. Normally, this zone contains only supports. This zone is part of the foundation so it must be strong and stable. Exposure time is half of the second zone. The lifting height should be set to 5 mm when using the large build platform and 3.5 mm when using the small build platform, with a lifting speed of 15 mm/min. For example, if the layer thickness is 0.05mm then you have 40 layers for the first 2 mm of printing with a large build platform. If the base consists of 6 layers, the remaining 34 layers will be assigned to this zone.
  4. Fourth zone:
    This zone normally contain layers for supports plus a few layers of the model to make sure the adhesion for the tips is strong. This zone is also part of the foundation and the exposure time is the same as the third zone. If the model has fine supports or has supports near the inner edge of the build area, you need to increase the exposure time at least 2 times. The lifting height should be set to 3.5 mm with a lifting speed of 15mm/min.
  5. Fifth zone to Seventh zone:
    Layers for both supports and model. Gradually lower the exposure time from the 5th to 7th zone to avoid horizontal lines caused by non-uniform layer shrinkage. The lifting height depends on the cross-sectional area and ranges from 2mm to 5mm with a lifting speed of 15mm/min.
  6. Eighth zone: Layers for model only.
    These layers consist of pure model slices. Use the regular exposure time with a lifting height ranging from 2mm to 5mm and set the lifting speed to 15mm/min.

The exposure time is estimated from the baseline exposure time (Please refer to the table above). The lifting height should be set to 3 mm with a lifting speed of 15mm/min. Slower speeds are recommended for layers with larger exposure areas. Smaller models can print with faster speeds.

The lifting speed impacts the warpage on the resin container’s Teflon film. If the lifting speed is too fast, especially for layers with large exposure areas, it may stress or lift the Teflon film. Prints that have irregular shapes are less sensitive to the warpage. To reduce warpage, please use a slower lifting speed. For fine features, please increase the exposure time in the 5 to 8th zone to increase the strength of the cured resin for certain features, such as an overhanging angle and biomedical tissue scaffolds.