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Comprehensive 3d Printing Troubleshooting Guide- Part 8

Comprehensive 3d Printing Troubleshooting Guide- Part 8

More print quality issues

 

“Stepped” or Offset Layers in Print

What’s the problem?

The lower and top layers shifted, causing a stepping effect through the print.

Why is it happening?

Offset layers can be caused by many minor issues, such as knocking the printer during the print process. More complex causes can be bent or misaligned rods, or even the nozzle catching on the print and causing a slight shift in position of the platform.

Troubleshooting

Check Printer Base

Check the location of the printer to ensure it does not wobble or is not prone to being moved or touched during the print. Place the printer on a stable base in a location where it will not be jostled while printing.

Check that the Print Bed is Secure

Many 3D printers use detachable print beds. Over time, clips and screws can work loose. Ensure that when you reinstall the print platform, it has been clipped or bolted tightly in place to avoid any slip or movement.

Check for Warped Upper Layers

A print’s upper layers can easily warp if cooled too quickly. As the layers warp, they rise and can cause an obstruction to the nozzle as it moves. In most cases, the print will release from the platform, but if this does not happen, the stepper motors can move the print and platform. If your prints are suffering from warping in the upper layers, try reducing the speed of the fans slightly.

Reduce Print Speed

Increased temperature and flow can reduce print times. However, this may result in print consistency issues as the machine struggles to “keep up” with the rapidly extruding filament. If you hear any noise (like clicking) during the print, check that the filament is not slipping and slightly reduce the print speed before continuing.

Check the Belts

If layers are still shifting, check the belts. Check belts by pinching the two together. The tension in each belt should be the same. If not, adjust the belt position to ensure the belt tension is even. Over time, the rubber belts will stretch and can slip off the drive pulleys. If they remain loose after tightening, replace the belts.

 Check the Drive Couplers

Drive couplers can be found connected directly to a stepper motor and one of the main rods that drives the print head. Carefully rotating the coupler reveals a small grub screw. Hold the rod and the attached belt, then tug the belt and try to force the pulley to turn. You should find that there is no slip between the coupler and stepper or rod. If there is, tighten the grub screw and try again.

Clean and Oil the Rods

Wipe and oil the rods. Over time, debris can build up on the rods, increasing friction and impairing smooth movement.

Check for Deformed Rods

If you see the print head falter at certain points, one of the rods may have become slightly bent. To identify which rod is bent, turn off the machine and ensure no power is going to the steppers. Move the print head through the X- and Y- axes. If you feel resistance, something is wrong.

Check that the rods are aligned. If they are, remove the rods and roll them on a flat surface, which will show which is bent.

Bridges are Messy

What’s the problem?

The printer fails to successfully bridge gaps between 1 and 3 cm. The extrusion may be too thin, sagging, or flowing down the height of the bridge rather than across.

Why is it happening?

Most filament is surprisingly resilient to bridging, and well-calibrated printers can produce notable bridging span distances. However, many issues can lead to bridge failure.

Different slicer applications handle bridging in different ways; applications such as Simplify3D having a special bridge option for adjusting extrusion and cooling.

The most common related issue is gap size. The distance over which the printer can reliably print bridges will vary depending on model and material type.

Extrusion speed is critical because if the print head moves too quickly, the speed and vibrations will damage the filament before it has set.

High extrusion temperatures can also lead to sagging filament.

Troubleshooting

Check the bridging capabilities

Perform a test print with columns and bridges of different distances to check how far your printer will reliably print, beginning with a 5 cm gap. Anything between 5 and 10 cm is good, and 15 is considered excellent though somewhat rare.

Add supports

Add supports below the bridge structure.

Increase fan speeds

Increase extrusion fan speed to ensure that the filament cools quickly, which allows for larger bridges.

Decrease extrusion speed

Rapid extrusion causes more harm than good when bridging. Decrease the extrusion speed until the has time to set as the distance is bridged.

Use Simplify3D

This dedicated 3D print software features a bridging option that automatically recognizes any areas of the print that require greater cooling and slower extrusion speeds.

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TdrYDFMOB - September 29, 2020

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