W5: 3D Scanning + Printing

3D Scannning

3D scanning seems like a pretty straightforward task, but like so many other things, it requires a thoughtful apporach. What you think is the whole task is actually just the beginnnig.

This is the device we have at the lab, an Artec 3D:

White surfaces work better than darker ones, so we tried something that we thought might be manageable, like a small remote clicker on an improvised stand.

We give it a go by scanning around the object. The software on the computer informs what the best scanning distance is, but the white table doesn't help, plus it's hard to scan the back.

The results are not very good, and we're not comfortable with the set-up, so we try something different. In the lab there's a bike helmet laying around, so we give that a try. To scan all sides, we improvise a rotating stand with a stool.

In this case, we keep the scanner mostly in the same positions, making sure we're keeping the recommended distance and angle by the sofrware.

The scanning process is fairly fast, so now we have to clean the mess[h]. The software makes it fairly easy with a range of 2D and 3D selection tools.

From there on, it's a reasonable wizard-style process with just a few parameters to configure.

Here's the "final" product. Of course, in a real case scenario, we would probably go back to tweak the cleaning and the closing of surfaces.

3D Printing: Design Rules

I tried three different printers to compare some of the design rules for this assignment:

A Snap-Maker that I had bought a couple of years ago to mess around and that was actually sitting in a box :(
A Zortrax M200
A Tiertime UP Plus 2. "Timeless reliability"... oh, well :D

Wall Thickness

Here's the Snap Maker

And here's the Zortrax

Clearance

In this case, the Snap Maker failed me... or maybe I failed her with not enough glue, heating and rafting. Everything was going smoothly but sadly the piece dettached halfway through.

The Zortrax did complete the job had also had better defaults for support, although the quality overall is a bit rough

Angle

Bridging

This is the only test we could ever complete on the Tiertime UP. Very, very unreliable machines... the lab has quite a few of them and there was always some issue. most tests just didn't run, the extruder wouldn't work, it would randomly stop half-way through, etc.

A big learning is that 3D printing amplifies frustration, as everything takes a lot of time and errors amount to a lot of wasted time.

Overhang

In this example we can see again a different approach to supports between the Snap Maker and the Zortrax

Surface finish

After the previous experience, I though I would do all the remaining tests in the same print, but that wasn't a good idea:

It takes WAY more time printing than doing them individually
If it fails, all of them fail

The other learning after stopping the process if that you can also do flexible strips in 3D priniting :)

Anyway, the print went fine. I'm again surprised at the quality and speed of the Snap Maker when compared to the other printers I've tried for this excercise.

Infill

In this case I paused the printing to take a picture, which I hadn't done previously

Dimensions

The outside is pretty much spot on:

On the inside, however, we need account for the difference.

Anisotropy

Thoughts on the different printers

I have to say I came surprisingly happy with my purchase of the Snap Maker. It has proven to almost always produce better results, faster and more reliably than the other ones that I tried for the assignment. I thought it'd be more of a hobbyist toy, but now I can see I can use it for more things, not to mention the eye-opening CNC carving of PCBs that I can also do with it!

3D Printing: Model

The idea is to do a a very simple proof of concept with two solids in a disposition that would be very complicated to achieve by substractive means. In this case, a sphere within a cube.

Fusion 360 likes to take its sweet little time to cloud-export to STL a simple file like this... as in MINUTES!

The first try is optimistic, with no supports. Perhaps unsurprisingly, it doesn't work:

Next try with light support for the sphere and the cube. I'm doubtful about the removal of all of it...

It turned out quite alright!

Final Project Designs

Fixture

In order to link the servo motor and gears to the spinning ring, I needed to create a piece that would both connect and hold them together. Here's the original sketch: