This week, our team focused on adjusting build features and parameters in order to optimize the part build time while keeping the desired part strength, flex, and size. We brought the multiple CAD models into Cura and played around with different parameters to reduce build time as well as support material.
Updating Cura Parameters:
Changing infill densities of resistance bar at 55 mm/s and 0.2 layer height:
|
Infill Percentage |
Build Time |
|
20% |
31min |
|
15% |
30 min |
|
10% |
30 min |
|
5% |
30 min |
We found that changing the infill percentage below 20% negligibly affects the build time. Adjusting the infill percentage will be for the purpose of changing the strength needed to flex the bar. We now know that this property will have little effect on the build time so adjustments of infill can easily be made without affecting the build.
Changing print speed of resistance bar at 15% infill and layer height of 0.2 mm:
|
Print Speed (mm/s) |
Build Time (min) |
|
55 |
30 |
|
65 |
27 |
|
75 |
25 |
|
85 |
24 |
Increasing the print speed decreased the build time. This trend isn’t surprising but with each increase in print speed, the build time decreased by a smaller amount.
Changing Layer height at 15% infill with print speed of 55 mm/s
|
Layer Height (mm) |
Build Time (min) |
|
.15 |
40 |
|
.20 |
30 |
|
.25 |
26 |
|
.30 |
22 |
Changing the layer height had a significant effect on the build time as expected.
While the build time for each part will be different, the trends we observed here should be consistent. We will print the resistance bar at multiple infill densities to create a range of resistances but will print at 0.2mm layer height and 65mm/s so that the parts print at a reasonable rate while still having high resolution.
Optimized Geometry:
The resistance bar geometry was redesigned with a more triangular geometry in attempt to reduce build time while maintaining the part strength. With this new geometry, there is no overhang which will result in consistent builds with no support needed. The new geometry also removes a significant amount of material compared to the original resistance bar. Testing will be done next week to compare the strength of the new design compared to the original. However we can confidently say that the new geometry improves both build speed and build consistency.
Optimized orientation:
For the fingertip component we determined the optimal orientation to be as shown above. This way the amount of support material used will be minimized. While this may not be the quickest way to print the part we decided that minimizing support material is more important.