General guide

Introduction

So this page contains general tips for setting up 3D printers for working with HARZ Labs resins.

The page is divided into several sections, each section will vary from printer to printer (for example, whether the VAT is filled with PDMS, or the FEP film).



Each printer requires an individual adjustment
Even within a single model 3D printer various settings may be required (this is especially noticeable when working with DLP technology).

We have collected as much information on setting up the pair of 3D printer and resin for better user experience and to achieve the highest possible print quality.

Testing models

Any setup of a 3D printer must follow a certain technique, which is based on the testing model.

In our practice, we use two testing models to setup the printing parameters. The first one - a simple quick-print model is needed for a rough tuning, and the second one for fine tuning.

Of course, you can use your own models for setting up your printer.

Layer thickness

Depending on the level of the printer you are using, the thickness of the layer may vary from 4 μm to 300 μm. However, the most commonly used layer thicknesses values range from 20 μm to 100 μm.

In addition to the printer resolution, it is also necessary to take into account the properties of resins. Resins designed for printing with layers of 100 μm and 20 μm differ and have different critical depths of curing.

Color	Accuracy	Minimal layer thickness
Red	Accurate	up to 40 μm
Cherry	High-precision	up to 4 μm
Transparent	Accurate	up to 40 μm
White	Accurate	up to 40 μm
Gray	Accurate	up to 40 μm
black	High-precision	up to 20 μm

Curing time

Curing time depends primarily on the type of UV-source and its emission power. Secondly, curing time also depends on resin activity.

A more active resins requires less time for curing the layer, which means that the model will grow faster. Contrastingly, a less active resin would not behave aggressively and is ideal for PDMS and FEP. The goal of our developments is to find a balance between these two sides.

The bottom layers require additional exposure. Our general recommendation is that their exposure time is 3-4 times longer than the main layers.

Z lifting height

Z lifting height of the table depends on many factors. However, a determining factor is the printer type.

In other words, do you have a horizontal movement of the VAT or not, is there a tilt, what kind of VAT material is used, what length of exposure you have set and etc.

If the VAT is with a FEP film, the minimum table adjustment height depends on the area of the model. On the FEP film the resin fully cures the layer and possibly stretches the FEP film behind the model (in contrast to PDMS).

Type of VAT	Lifting height
PDMS	0-3mm
FEP	2-6mm

Time for relaxation

The first depends on the mechanics of the printer. Time is needed for raising and lowering the table, as described in the first paragraph, affects.

The second depends on the viscosity of the resin. Less viscosity - less relaxation time after lowering the table.

Viscosity	Relaxation time
Low viscosity	0.2-0.5 s
Medium viscosity	0.5-1.5 s
High viscosity	1,5-10 s