Pattern Quality Troubleshooting

p/n 31-D095 Rev B

 

Issue

Example Photo

Root Cause

Remedy

Dents/Dings/Scuffs IMG_3462a.jpg Handling during IPA bath or during de-bulking.
  1. Use coated wire racks (PVC) to help mitigate dents and dings from fixtures. Use care and caution when moving patterns.
  2. Reduce need to handle patterns by de-bulking less, rotating less often, and inspecting less.
Bumps of build material IMG_3464a.jpg Print Configuration Re-orient portions of geometry which saw bumps to be less horizontal. Tilt patterns 5 to 10 degrees on both the x and y axis.
Cracks IMG_3436.JPG

Thermal Stresses

Mechanical Stresses

  1. Avoid quick temperature changes. Typically this is seen during movement from the bulk removal bath to the rinse bath, or during the drying process. Make sure to rinse your patterns with water to slow the evaporative cooling of the patterns.
  2. Only use the rack to move patterns and do not remove patterns from rack until they have thoroughly dried.
Feature warp/sag IMG_9251a.JPG

Thermal Stresses

Mechanical Stresses

  1. Avoid over-exposure to high temperature environments. Typically this is seen during transport in a hot container (van, airplane, etc)
  2. Be careful not to let flat geometries overheat when de-plating. Move heat source around plate frequently and remove patterns quickly from plate.
  3. Don’t rest pattern on its smallest, weakest structures
White Surface IMG_3376.JPG Excess Amount of Time in IPA bath
  1. This will not affect the final quality of the cast.
  2. If you find this visually objectionable, you can follow the show patterns guide for removal of the white surface.
Build and Support Delamination 1.png Thermal Stresses
  1. Rotate flat geometries 10 degrees in x and y axes. For more information see: Pattern Orientation for Printing.
Overhanging features breaking during post processing

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Large mass of suspended feature
  1. Add struts or runners to printed geometry to support overhanging or cantilevered features. These can be removed after the pattern has been gated and attached to the sprue if they interfere with metal flow.  Or they can be cut off after casting.
  2. Avoid manually handling while in IPA bath and immediately after removing from bath.  Use a support cradle or carrying basket to move patterns in and out of the baths.
Thin blades or features breaking during handling

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Long thin sections are very fragile and easily cracked/broken.
  1. Handle geometries by the most robust sections. Avoid contact with small features.
  2. Add auxiliary bars across thin features to support pattern. This will give a convenient place to handle the pattern while it is in the bath or transporting. These bars will be removed after casting. See Pattern Orientation for Printing for more information.
  3. Place patterns on soft surfaces, such as foam, or bubble wrap, or layers of paper towels during transport.