Frequent issues with SLA 3D printing – troubleshooting guide

Frequent issues with SLA 3D printing – troubleshooting guide makenica.com/frequent-issues-with-sla-3d-printing-troubleshooting-guide February 25, 2021

The possible problems with SLA 3D printing Nothing is Printing After hours of trial and error, no print is quite right. The Print does not begin in the first place, or after hours of exaggerated attempts, the final Print does not conform to the plate and loses its structural integrity.

Cold resin What's the problem?

Like many FDM 3D printing filaments, the ambient temperature can significantly affect whether the photopolymer resin is set during the SLA 3D printing process.

If the resin is too cold, it is unlikely to be set and, if it does, maybe set inconsistently, resulting in partial prints and low adhesion of the plate.

Why is this happening?

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Unfortunately, for those in the material science niche, this is not readily explained. Simply stated, certain materials require a temperature equilibrium to ensure stability. Check out any scholarly articles if you want more info.

Some resins can require temperatures as high as 25–30 °C. Troubleshooting: Shift your printer to a warmer location The choice to do so depends on the location of your home or store. However, for those who do not live in very cold climates, shifting the printer to a somewhat warmer spot might be sufficient for taking the material to a "green" state in which it is very solid but not yet cured.

Invest in a chamber heating Few products are designed for 3D printer heating, but some dynamic manufacturers have looked to the fledgeling culture surrounding home incubators for a solution. If possible, consider investing in an incubator heater package that includes a heater, fan, thermostat and power supply.

Printing too fast What's the problem?

In SLA 3D printing bangalore, a UV light source—usually a laser—hardens photopolymers' resin. The resin must be subjected to enough light before solidification to ensure proper curing.

What causes this problem?

If the laser runs too rapidly or the laser is under powered, underexposure can result in nothing printing or printing turning out fragile and brittle.

Troubleshooting: Decrease print speed Verify that the resin is heated to the recommended temperature. Then reduce the printing speed. Depending on the printer, the printing speed in the slicer settings can be slowed down.

Under powered Laser What's the problem?

Like printing too rapidly, an under powered laser may underexpose the resin to UV light, resulting in poor print quality or inaccurate printing.

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What causes this problem?

If the laser is in good condition, it is possible that the laser power settings are to blame.

Troubleshooting: Increase the strength of the laser If your printer settings allow, increase the laser power in small increments to determine the correct settings for reliable and efficient printing for your particular resin form and printing speed.

Do not merely raise the laser power to the maximum possible setting, as this will result in a sloppy surface finish and destroy the interface layer within your printer's resin vat.

Print failure Prints that do not conform to the print plate What's the problem?

Printing does not adhere to the printing plate and peeling, or complete destabilization is observed.

What causes this problem?

Specific SLA 3D custom printers can be repositioned to the next printing layer in a way that produces more peel force than the model can manage. For the top-down SLA 3D printers, the peel force is the suction effect applied to prints any time the print plate and the bottom of the resin vat are removed for repositioning. Depending on the process by which this happens, there are some tricks. These, you can do to eliminate or at least mitigate this force.

Preparation of the print plate can also impact this problem. Bottom-up SLA printers on a flat metal plate hold well whether the plate is finely textured or rough. Ghosting on the interface layer in the resin vat can also affect how the laser sets the resin.

Alternatively, the resin could not be warm enough. As Print progresses and the resin level decreases, minor temperature variations can affect the resin environment.

Troubleshooting: Repositioning the Print If your printer uses a tilting resin vat, a gradient is formed over the print plate.

Positioning the Print in a print plate region with less peel force will guarantee successful bonding to the Print while reducing stress on larger sections free-standing or dependent on thinner supports.

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Level Vat Level the bed and the vat according to the directions of the maker. If this cannot be achieved in isolation, re-calibrate the printer from scratch.

Check the temperature If the resin is too cold, it may not be well enough and may have low adhesion.

Heat the resin and printing chamber (maybe by repositioning the printer in a warmer room) before trying to print again.

Check for the resin vat interface layer.

Check for the resin vat interface layer for ghosting and overall wear. If the damage is detected, substitute the interface layer with your own (such as Solaris Silicone), purchase a new interface layer, or add a new vat.

Filter the resin If there are small bits of resin floating within the vat, this can impede continuity in the printing process, leading to troublesome adhesion.

Comb through the vat after each Print. This is to trap and clear these particles and dislodge any resin stuck to the bottom.

Remix the resin If you have taken the above step and filtered the resin to print disruptive particles but then left the printer alone for a few days, there is a risk. The resin will settle, with the heavier pigment of coloured resins settled into their layer, which will print inconsistently as the Print continues.

Sand the print plate Perhaps the factory-made plate is too slick for most prints to adhere correctly.

Gently sand the print plate with medium-grit sandpaper. Clean the plate carefully afterwards to prevent contaminants' entry into the resin that would interfere with the printing process.

Detached or Moving Print Segments/Supports What's the problem?

A piece of hardened resin moved, either entirely separating or shifting enough to interfere with other parts of the Print.

What causes this problem?

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Vat conditions and print orientation are two common factors in this dilemma. Printing can be improperly directed to withstand peel forces, resulting in distorting motions that allow parts or supports to separate.

Such movement in the component would contribute to creating subsequent layers on the vat interface rather than the Print itself.

Inadequate support structures can also trigger this problem.

Troubleshooting: Hollow large prints Consider hollowing and inserting drainage holes where possible for prints with broad surface areas at either position. Instead of causing a wide, flat surface to pull away from the bottom of the resin vat with each shift of layer, the thinner model form detaches each time.

This requires even less force and is less likely to contribute to layer separation, but this works well when drainage holes are added using modelling or slicing software.

Without drainage holes, a pool of unset resin would be stuck within the Print, which is expensive and unsustainable.

Stronger supports Peel force may be the cause for a failure print; consider strengthening your support.

Increase the width of the tips on which the supports meet the model's printed portion by a fraction of a millimetre and add the struts between them.

If this is not adequate, consider adding more support. Notice that this can increase the post-printing time and effort needed for the creation of a clean print.

Check/Secure Printing Network Check that your 3d printing online platform is adequately protected, as a slight difference in the printer's location can lead to misaligned or separate layers.

Reorient the Print Check the print orientation. Print alignment problems may be compounded as Print progresses, leading to shifting of layers and curing issues. The following factors are essential to the verification of print orientation: Positioning: Many bottom-up SLA 3D printers have a peeling mechanism that removes the print plate from the bottom of the resin vat while repositioning the next layer on the Z-axis. Depending on the printer, this peel force's intensity can vary in various areas of your Print. If this is a known issue for your printer, you can maximize the chance that printing can resolve these problems by placing it in an area subjected to week peel force.

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Support overhangs: Like FDM 3D printing, extreme overhangs require some form of support for successful printing. With some 3D models, you can reduce the need for support by angling your model or decreasing overhang angles.

Minimum Points (Minima): Minimum Points are isolated portions of the prints that are not directly linked to the main body. Such minima require support, as they are highly likely to break away and float free in your resin vat. Alternatively, you may eliminate the need to support a tactical model orientation minima, such as flipping a body model to print the head first as the body taps the arms and legs without far extrusions.

Cupping: This occurs when a hollowed area has a high suction effect on the print surface. If the "cup" is shallow, to minimize the cupping effect, angling the Print may be sufficient.

Using the modelling software, drainage holes can be added to the model, enabling the resin to flow freely with each layer's change.

Print quality issues No sound, shaking, or print-process issues have been identified, but the Print produced ends up being of low quality.

Layers have been separated (Delamination) What's the problem?

Print layers are not uniformly bonding or separating in certain sections.

Why is this happening?

Delamination—separation or problematic bonding between print layers—may be caused by many underlying issues.

Print orientation can be deactivated, resulting in pieces being printed in isolation. Poorly mixed resin and ghosting on the vat itself may also do this. Besides, delamination can occur after successful printing during the post-processing step. If the material has an especially poor bonding layer, washing the part in IPA for too long can further weaken the layers, allowing the part to break apart or collapse.

Troubleshooting: Suppose portions of the print show poor layer bonding, over-washing in IPA will further weaken it. Restrict the IPA wash cycle to a minimum and stir the unsettled resin softly and rapidly before rinsing with water.

Support Minima in your prints can lead to stability problems in SLA prints where they are not adequately supported. Generate supports all extreme angles and points that are not directly related to the main Print at its highest point.

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Clear the path of the laser Check that the resin is debris-free and well blended. Then examine the interface layer for ghosting, which can obstruct the direction of the laser. If extreme ghosting is detected, replace the Interfacing layer or whole vat, if required.

Small Fins and Disks attached to Print (Ragging) What's the problem?

The dried resin flakes have been combined with the settling resin, resulting in a lowquality surface finish with extruded portions that are not part of the model.

Why is this happening?

This problem also emerges because of a vague optical direction. The laser may be diffused, creating leakage outside the original casting location.

Settled resin, resin clouded with large particles from previous prints, or smudged planes may also add to this issue.

Troubleshooting: Filter Resin Filter resin to clear the residual clumps or particles from past prints. Many 3D printing shops carry paper and mesh filters designed to trap large particles that would otherwise fog the resin throughout the printing process.

Mix the resin If the resin has not been used for several days, it may have settled, allowing the pigments to break in dense layers. Mix the resin to ensure that the pigment and the photopolymer are uniformly spread, and no streaks exist.

Checking/Clean Optical Path Some machines allow users to access the transparent internal barrier protecting the laser/galvanometer. Check that everything is free from dust, fingerprints, oils, and residues that can prevent it from passing through cleanly.

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