Site Information


 Loading... Please wait...


Scanning Electron Microscope Imagery of 3D Printed Plastic Traces

Posted by Alex R English on

Some time ago we were helping out the Biology Department at Walla Walla University get a printer dialed in for some work they wanted to do. In our work with them, they gave us these images they took with the help of Whitman College, using their scanning electron microscope and gave us permission to publish. It's been a while, but we ran onto those files again and thought the community might find them interesting.

All of the prints are done with the 4043D PLA we were selling at the time, and printed on a modified MakerBot Thing-O-Matic. The flat surfaces with the white lines, streaks, fuzz, or lightning-like patterns are where the plastic was parted with a razor blade to take the images of the infill.

This image was of particular interest, notice the twisting on the traces caused (presumably) by the changing directions of travel of the print-head and friction and bonding of the traces to prior layers. This was a grid / rectangular infill pattern at 45 degrees, cut on what we believe was the ZY plane.

Scanning Electron Image of PLA traces

Here is a closer view of the same piece. Here we get a much better view of the twisting in the traces, which is most pronounced near its interfaces with other traces. The lighting marks on the cut surface appear to be some combination of loose fibers of resin (seen better in a later photo) and embossed patterns we believe were created by the internal stresses of the traces formed during printing, cooling, and subsequent cutting.

Scanning Electron Image of PLA traces - note the twisting near the interface

In this next image we see the interface between the perimeter traces and infill traces. It is good to see that level of bonding between the traces toward the interior, but it looks like the outermost perimeter traces weren't very well bonded to the adjacent perimeter.

Scanning Electron Image of PLA traces where infill meets perimeters

Here is another view of the infill that shows off the interface between opposing layers of the grid infill very well. Notice the twisting seen here as well as the distortion (smooshing) in the trace where it was laid down on the prior layer (oriented in on the perpendicular).

Scanning Electron Image of PLA traces - another view of deformation and twisting at inter-layer trace interfaces

This last image was of the same design, printed with linear infill. For whatever reason we see less twisting in the traces, and less extreme deformation at the trace interfaces (which where there is less adherence when molten may actually mean a weaker part if there isn't as much of a mechanical bond from the deformation where the traces meet). The fibrous bits on the ends of the cut traces are just that - fibers of PLA resin smeared when the part was cut open. The fibers in this image are more numerous and larger than on other photos, possibly because of differences in the sharpness of the blade used, differences in printing conditions, or other uncontrolled factors.

View Comments

Accuracy vs Precision and Threaded Rod vs Leadscrews in 3D Printers

Many Personal 3D Printers use threaded rod as a drive mechanism, usually just for the Z-axis, most of the rest use precision leadscrews. We've seen debate in multiple forums about which is better, and about how much of a difference it actually makes. We've even heard the argument that leadscrews are a waste of money, [...]

Read More »

Vapor Smoothing and Polishing PLA with Tetrahydrofuran (THF)

Acetone has been used for some time to treat ABS parts, either by polishing, vapor smoothing, or even using it to stick parts together. Likewise, Methyl ethyl ketone (MEK) has been used to the same effect with ABS. We found Tetrahydrofuran (THF) to be the best option in our assessment, but be warned that there [...]

Read More »

Weathering of 3D Printed PLA Objects

We've received questions about how 3D Printed parts handle weather and exposure. It's been just over a year since my post about the 3D Printed Garden Tools. The slug trap in that post received the most attention, and was also the most structurally interesting. When spring was over and the great slug war abated, I [...]

Read More »

Recharging Reusable Indicating Silica Desiccants

Keeping your plastic dry is critical. It greatly improves both printer reliability and print quality. A week ago, we announced our reusable indicating silica gel desiccants, along with some other products. While we mentioned in the product description that you can dry these out in a microwave to reuse them, we thought we'd give a [...]

Read More »

Thing-O-Matic Mk7 PLA Set-up and Troubleshooting (Likely Mk8)

While a vast improvement over previous extruders, the MK7 can still prove challenging for those wanting to get started with PLA. However, while PLA is more picky in the settings surrounding how it is printed, its benefits over other printing materials make getting over the calibration hurdle well worth it. It has little to no [...]

Read More »

Investigating Flash Breaker Tape

We're always working to find better ways to do things.  We feel it's important to report on the things that don't work out as well as on the successes.A while back we decided to try using Flash Breaker Tape as a print surface material, seeing if it had any advantages over Polyimide Tape (also known [...]

Read More »

What to do With a 3D Printer: Make a Custom Microscope Adapter

I had an old Nikon medical laboratory microscope and really wanted to find a way to take photos through it so I could share what I was seeing with others. After looking around online and discovering that my only likely option was to have one custom made at great expense, I decided to build one. Here [...]

Read More »

Filament Tolerances and Print Quality

Filament Tolerances is a subject that doesn't get much discussion, yet is arguably the most important quality to look for when choosing a plastic supplier. Hobby Printers use what is traditionally known as Plastic Welding Rod. In the application of welding and the like, maximum precision is not necessary; when it comes to 3d printers however, precision [...]

Read More »

Makerbot Thing-O-Matic Power Consumption

IN BRIEF Makerbot Thing-O-Matic with MK7, Gen 4 Electronics, 1/8" Aluminum Heated Print Bed ( Polyimide Covered) Printing ABS: ~108 Watts Printing PLA: ~76 Watts Idle: ~10 Watts 8 Hr. Print in ABS @ 7cents per kwh: ~$0.06 Forgetting to disable stepper motors over the weekend: ~$0.23POWER USAGE STATISTICS This data is applicable to the currently shipping (Oct 2011) Makerbot Thing-O-Matic (Power for a [...]

Read More »