Gripper finger: six positions on the build plate
One part, one set of rules, six ways to put it on the build plate. The support it needs changes by a factor of almost eight.
The labels inside the chart are in Serbian. Every value in the chart is repeated in the table below.
What was compared
A gripper finger for an industrial gripper, printed in PA6-CF on an FDM printer. The shape came from topology optimisation, so its surface is stepped and not designed for printing. The check was run once for each position with identical rules: surfaces more than 45° from vertical need support.
Results
| Position | Support (cm³) | Height (mm) | Support contact area (cm²) |
|---|---|---|---|
| As in the file | 6.6 | 90 | 2.2 |
| Upside down (chosen) | 4.3 | 90 | 8.2 |
| On its side, +X | 12.4 | 40 | 5.3 |
| On its side, -X | 4.7 | 40 | 13.2 |
| On its side, +Y | 31.8 | 50 | 2.6 |
| On its side, -Y | 32.6 | 50 | 3.8 |
What the numbers say
- Support volume runs from 4.3 to 32.6 cm³. The worst position needs about 7.6 times as much as the best one.
- Lying on the +Y or -Y side is the worst choice for this part, with 31.8 and 32.6 cm³.
- The least support is not the whole story. Upside down needs the least (4.3 cm³), but the print is 90 mm tall and 8.2 cm² of the part touches support. Lying on the -X side needs almost as little (4.7 cm³) and is only 40 mm tall, but 13.2 cm² touch support. Which is better depends on how much print height matters against surface left to finish.
- The report frames the position with the least support that also stands stably: here, upside down.
- A topology optimised part has a stepped surface and should be smoothed before printing, otherwise support and steps meet on the same surface.
What to do with this
Do not pick the position by eye. Run every position with the same rules and compare three numbers: support volume, height and the area that touches support. Dokimion does this for your part and shows the three best positions with a picture, see the guide on part orientation.
These are calculated values from the check, not measurements of printed fingers. Shape optimisation of the finger itself is a separate topic.
Shape optimisation of the finger itself is coming to Dokimion as the DfAM Optimizer module.
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