How to Evaluate the 2015 Make: 3DP Test Probes

Want to see how your 3D printer stacks up to the competition? Download our test-print files and follow along.

Printing:

For evaluating overall system (machine, software, and materials) performance, print the following at default or “medium” settings. For most machines, this translates to a layer height of 0.2mm and default speeds and temperatures.

If evaluating multiple machines, it is imperative to use the same material, preferably from the same spool (unspooled lengths of filament can be used for individual prints to facilitate this). The Make: Magazine 3DP testing team used Ultimachine orange PLA for all PLA machines.

DOWNLOAD AND PARTICIPATE!

The 2015 3DP Test Geometries, created by Andreas Bastain, are available from Make:’s YouMagine and Thingiverse accounts. Print them yourself and report your settings and scores!

How Much Filament?

1. dimensional_accuracy_test.stl requires approximately 0.99m of filament
2. bridging_test.stl requires approximately 1.54m of filament
3. overhang_test.stl requires approximately 2.00m of filament
4. negative_space_tolerance_test.stl requires approximately 2.54m of filament
5. retraction_performance_test.stl requires approximately 0.52m of filament
6. XY_resonance_test.stl requires approximately 0.95m of filament (if your slicer cannot do 0.5mm walls, use XY_resonance_1.0mm_walls.stl)
7. Z_resonance_test.stl requires approximately 2.64m of filament 
8. The Maker Faire Robot Action Figure (with supports) requires approximately 3.58m of filament

Here’s how to evaluate and score your prints.

1. Dimensional Accuracy

Using digital calipers, measure the second from the bottom tier of the print (with a target diameter of 20mm) across the X and Y directions, following the guide on the bottom of the print. Differences between X and Y measurements indicate the magnitude of backlash present in the system.

• Assign the print a “1” if average deviations in X or Y are greater than 0.4mm.
• Assign the print a “2” if average deviations in X or Y are between 0.4 and 0.3mm.
• Assign the print a “3” if average deviations in X or Y are between 0.2 and 0.3mm.
• Assign the print a “4” if average deviations in X or Y are between 0.1 and 0.2mm.
• Assign the print a “5” if average deviations in X or Y are between 0 and 0.1mm.

2. Bridging Performance

Inspect the five bridges for dropped perimeters and infill.

• Assign a “1” if any bridge has dropped infill.
• Assign a “2”if only the longest two bridges have dropped infill.
• Assign a “3” if none of the bridges have dropped infill, but all have dropped perimeters.
• Assign a “4” if the shortest two bridges compiled without any dropped perimeters.
• Assign a “5” if all bridges compiled without any dropped perimeters (drooping of less that 2mm is acceptable).

3. Overhang Performance

Inspect the 30, 45, 60, and 70 degree overhangs, looking for drooping perimeters, wobbling extrusions, and infill hemorrhaging.

• Assign a “1” if the printer did not compile any of the individual overhangs. Assign a “2” if the printer compiled the geometry but dropped loops and infill on the 60 and 70 degree overhangs.
• Assign a “3” if the printer only dropped loops on the 70 degree overhang.
• Assign a “4” if the printer didn’t drop any perimeters and the surface of the 60 and 70 degree is only slightly different from the surface of the 30 and 45 degree overhangs.
• Assign a “5” if there is little distinguishable difference in surface structure between the four overhang angles.

4. Negative Space Tolerances

Remove the captive pins by hand without using tools.

• Assign the print a “0” if no pins can be removed.
• Assign the print a “1” if the 0.6mm radial tolerance pin can be removed.
• Assign the print a “2” if the 0.6mm and 0.5mm radial tolerance pins can be removed.
• Assign the print a “3” if the 0.6, 0.5, and 0.4mm radial tolerance pins can be removed.
• Assign the print a “4” if the 0.6, 0.5, 0.4 and 0.3mm pins can be removed.
• Assign the print a “5” if all pins can be removed.

5. Fine Positive Space Features Performance

Evaluate based on the quality of deposition composing the spires:

• Assign the print a “1” if the spires did not compile due to extruder jam/lack of material flow.
• Assign the print a “2” if the spires compiled but are densely connected by strands of material.
• Assign the print a “3” if the spires compiled and there are some connecting strands but the main deviation from target geometry is due to volume flow issues (under- or over-extrusion).
• Assign the print a “4” if the spires compiled, there are no connecting strands, but there are volume flow issues.
• Assign the print a “5” if the spires compiled and there are no connecting strands and no stepping or ridging due to volume flow issues.

6. Mechanical Resonance in XY

This test evaluates both resonance in the XY gantry, deposition control during linear extrusions, and deposition control at layer changes. As resonance is difficult to measure quantitatively, this is a binary test.

• If there is any rippling at the corners or at the midpoint of the print wall with the inset, assign the print a “fail” value of “0”.
• If there is no rippling, assign the print a “pass” value of “2”.

While expressly designed for evaluating resonance, the print can also be used to evaluate deposition control in a more qualitative manner (inconsistent extrusion width, standing wave effects).

7. Mechanical Resonance in Z

This test exposes resonance in the Z axis if present and is subject to a binary evaluation.

When illuminated from above, if there is a noticeable loss of layer registration in the top half of the print, manifesting as horizontal ridging, assign the print a “fail” value of “0”.

If there is no loss of layer registration with increasing Z height, assign the print a “pass” value of “2”. In addition to evaluating Z resonance and layer registration, this print can expose misalignment in the Z-axis if there are consistent ridges of the same pitch as the leadscrew.

To get the total mechanical resonance score, add the XY and Z scores.

Documentation and Sharing:

Please use the “I Made One” button on your file sharing site of choice to share your results! Make sure to include the following information with your photo(s) of your completed test prints:

• Machine make and model
• Slicer and slicing settings (layer height, number of shells, print temperature, extrusion multipliers, speeds)
• Print time – Start with a room temperature extruder and platform.  Begin timing when you start the print, and include the preheat sequence. Keep timing through any post-print sequence, like the extruder or platform returning to a homing position.
• Filament source