Curl Management Using Insight

Stratasys

24 Jan, 2018 04:22 PM

Curl is defined as the distortion of horizontal surfaces caused by the shrinkage of a new layer as it’s applied over the existing layers, causing those layers to deform. This can be a challenge with parts that have thick cross sections or large at areas. InsightTM software features several tools that can mitigate part curl even on the most challenging geometries.

1. Step 1: Options

   Base Layer Modifications

   Two non-invasive ways to reduce part curl are to increase the support Base oversize and Base layers values in the Insight software Support Parameters dialog box. Change one or both values as needed to achieve the best results. These two options are ideal when used with standard and engineering-grade thermoplastics because they won’t leave any residual marks on the part.

   
   

   Removing Perforations

   For materials with breakaway supports the default support parameters add perforations (single model layers incorporated in the support at predetermined intervals) for ease of support removal. For geometries where a large amount of stress may induce curling, failure may occur at the perforation layer. Typically, these geometries have large areas of support and curling can be avoided by eliminating perforations.

   
   

   Anchor Columns

   On large at parts (> 305 mm [12 in.] long and >12.7 mm [0.5 in.] thick) that have the potential to curl due to differential cooling, anchor columns may be used to secure the model to the base. The anchor column is made of model material and will need to be mechanically removed after the build. Placement and quantity will depend on the part’s geometry and any observed curl in previous builds.

   
   

   Anchor Profiles

   Anchor profiles offer the advantage of anchoring the part in a uniform manner around its perimeter. This manual process is typically used when anchor columns aren’t sufficient to secure the part.

   
   

   
   

2. Step 2: Software and Materials

   Software:

   Insight software

   Control Center software

   
   

   Materials:

   All Fortus Materials

   
   

   
   

3. Step 3: Base Layer Modifications

   STEP A: From the Support menu, select Setup

   STEP B: Click to access the Support Parameters

   STEP C: In the Base section, make sure the checkbox next to Contour Base is checked (Figure 1)

   

   STEP D: In the Base section, increase the value in the Base oversize field

   STEP E: In the Base section, increase the value in the Base Layers field to add additional layers

   STEP F: Click the green check mark to confirm the change

   STEP G: This completes the base layer modification procedure

4. Step 4: Removing Perforations (Large Areas of Support)

   STEP A: From the Support menu, select Setup

   STEP B: Click to access the Support Parameters

   STEP C In the Perforation section, clear the checkbox next to Interval height to remove all perforations (Figure 2)

   

   STEP D: Click the green check mark to confirm the change

   STEP E: This completes the procedure to remove perforations

5. Step 5: Anchor Columns

   STEP A: From the Support menu, select Anchor column

   STEP B: Specify the desired Top diameter and Bottom diameter

   STEP C: Find the bottom layer of the part feature that will be secured using the anchor column. The next step is best done from a top-down view.

   STEP D: Position the cursor on the location where you want to put the anchor column and left click. The center point of the selected location will populate (Figure 4).

   

   STEP E: Click OK to confirm the anchor column location

   STEP F: Repeat the procedure to place any additional anchor columns.

   STEP G: This completes the procedure for creating anchor columns.

6. Step 6: Anchor Profiles

   STEP A: Configure the modeler

   STEP B: Click and orient the STL

   STEP C: Click to create part curves using the current parameters

   STEP D: From the Support menu, select Setup

   STEP E: Click to access the Support Parameters

   STEP F: In the Support to create section, select Supports extended for base. In the Base section, make sure the checkbox next to Contour base is checked and change the Base oversize to 0.00000 (Figure 5)

   

   STEP G: Click to create supports for the current job

   STEP H: From the Edit menu, select Copy Curves Through Z to extend the outer perimeter model contour down to the build sheet. Change the Copy mode to Specify through Z coordinate. Enter the desired value into the Through Z height field (in this case: -0.0400). Change the Destination group to Same as selected (Figure 6).

   

   STEP I: From the Edit menu, select Offset Curves to offset the outer perimeter model contour inward. Change the Offset direction to Inside closed curve. Enter the desired value into the Offset distance field (in this case: 0.0200). Change the Destination group to Same as selected. Change Keep original to Yes (Figure 7).

   

   STEP J: From the Edit menu, select Copy Curves Through Z to extend the new inner perimeter model contour down to the build sheet. Change the Copy mode to Specify through Z coordinate. Specify the desired value into the Through Z height eld (in this case: -0.0400). Change the Destination group to Same as selected (Figure 8).

   

   STEP K: From the Edit menu, select Offset Curves to offset all of the support contours that are outside of the outer perimeter model contour so that they are inside the new inner perimeter model contour. Change the Offset direction to Inside closed curve. Specify the desired value into the Offset distance field (in this case: 0.0700). Change the Destination group to Same as selected. Change Keep original to No (Figure 9).

   

   STEP L: Generate toolpaths (Figure 10).

   

   STEP M: This completes the procedure for creating anchor profiles.