6. 3D Scanning and printing¶
3D Printing week! Oh 3-D printers. Such a lovely idea, but overall, such a difficult technology to use.
Week’s Goals¶
Learning outcomes - Identify the advantages and limitations of 3D printing and scanning technology - Apply design methods and production processes to show your understanding.
Have you - Described what you learned by testing the 3D printers - Shown how you designed and made your object and explained why it could not be made subtractively - Scanned an object - Outlined problems and how you fixed them - Included your design files and ‘hero shot’ photos of the scan and the final object
Background¶
I got my first journey into 3-D printing when my then partner now wife won one at a conference! She had it in her classroom, and printed me off a 1.5 fl oz item of drinkware (winkyface). I thought they were cool!
When starting my job at MPTVHS, students obviously wanted to 3D print everything. I was approached by various teachers wanting to make scale models of salons, or start to make 3D printed limbs as a community service project, among others. It seemed great! All that stuff should be a breeze. Oh, was I ever a sweet summer child.
Enter actual 3D printers - they seem cool, but when you use them even a moderate amount, they tend to break all of the goddamn time.
The majority of the printers I have in my lab are FlashForge Creator Pros. I’d say they are a middle tier item, but perfectly suitable for what I need to do at the school. For the most part, the workflow is find or make a 3D file, slice it (I use the free FlashForge slicing software. If the .x3g format from Astroprint worked with my printers I would lean towards that, because free and cloud based. But alas!) Then export the .x3g files to an SD card, put them in the printer, load the appropriate plastic into the appropriate nozzle, and hope nothing goes wrong.
Printer Characterization¶
First, to characterize the printers! In addition to the FlashForges, I also set up an XYZ all in one with a printer and a scanner! Even cooler! The XYZ came with ABS, while I have PLA and ABS available for the others.
For testing, I used the All in one 3D printer test by majda107 on Thingiverse. Great file!
XYZ
Yeah, this came out bad. This printer, throughout everything, tends to have heat problems that leads to warping no matter what I try to do. The nozzle also gets clogged like this a bunch, and I’ve even cleaned it. Probably need to take apart the entire assembly, clean it, and reassemble, but I have other things to and other 3D printers to fix. The design of this (completely enclosed, tight-ish space for a large human such as myself) does not make it easy to fix. Hopefully it scans well?
FlashForge Creator Pro
ABS
Better! One thing from my experience, ABS is not as good at overhangs due to the heat required, and warps a lot more because of the same. Still works for a bunch of stuff though, but printers can be finicky and fail at low levels of things and do better at bigger ones. Go figure!
PLA
Great! PLA is an awesome material to work with, though can become brittle-ish if you leave it in a printer for a while.
Now that we know these things works, here’s a handy guide I have for troubleshooting. I don’t have pictures of these things, because the last thing that goes through my mind when I am trying to fix something is “Oh boy! I better take pictures of this so I can use it as documentation for a silly stupid website instead of fixing the actual problem!” because I have deadlines, dammit.
If it’s not sticking the bed: Check to see if the print bed is level. Are you using ABS? Adjust bed temperature or try a different material that doesn’t require a heated bed. Try changing the bed surface iif you need ABS (put down painter’s tape or something with some texture for it to adhere to.
Nothing coming out of the nozzle? Try to load and unload and load again the material. If that doesn’t work, clean the nozzle tip with a thin wire and clean it off with a brass brush (so you don’t scratch it). If THAT doesn’t work, or if the material is coming out of the nozzle in weird directions, there is probably a deeper clog that will require you to take apart the nozzle assembly, clean it, and put it back together. Get your screwdriver ready!
3D Modeling¶
Hmm…now to 3D print something that can’t be made subtractively. It took me a while to come up with something, because if you have enough patience, axes of motion, and precision, you can do anything subtractively - you just need to reposition it all. But I was thinking about it, and thought of overhangs and stuff like that. Eventually, I decided on making a mobius strip with a design in it, because that is definitely something that you can’t really do subtractively. As I am still relatively new to Fusion, and this can be a tricky thing to model, I consulted the all mighty google to see what it had. I found and followed this tutorial to figure out how to do it. Basically, make a circle, make a rectangle perpendicular to it, sweep the rectangle around the whole way and rotate it 180*(2n+1) degrees. Great!
Now let’s put some uniform holes in it. This had a bunch of problems trying to do a pattern on the surface, since Fusion was freaking out about the whole thing being one face anyways. Ok. First I tried to do something with a cylinder being subtractive, but yeah. Didn’t work. Next I decided to put point everywhere, make a plan tangent to the face of the mobius strip at those points (to get the rotation with the surface), then make a cylinder centered at every point there. Oh boy. It worked, but it took a long time.
But it worked! Here’s the print:
I decided to make it a bit fancier too. Add some ledges to it, really make it tough to do subtractively. While doing that, I also realized how I could do the faces a lot easier. Instead of trying to subtract cylinders, why not just take out spheres? They are symmetrical about all axes and can work! General flow: make one sphere centered at the center of the initial rectangle, cut it out of the strip, then do a circular pattern with the resulting face from the inside.
That was not infinitely easier (because let’s be real, infinity is a difficult concept to understand) but was definitely a more Alex-friendly way to do it.
I’m pretty satisfied with how it came out (Creator Forge Pro, blue PLA, with auto supports) and it is now used a talking piece at the school.
3D Scanning¶
Oh boy. Basically the whole way through this was a train wreck. I used an XYZ handheld 3D scanner on Windows. Tried to do a coffee mug, a dinosaur, and a dinosaur on a cup. Eventually, I figured out how to do it nice and slow and miserably. Maybe eventually I can build a lasy susan type deal for it with a motor so that it can work, but yeah. Some success, not a lot of it. I also tried to use the 3D scanner in that fancy XYZ printer, but it didn’t work great either and the software was giving me issues. But hey, I got a dinosaur standing on a generic blue cup scanned, so I’ll take it!
Scanning target - let’s see how the models come out!
The dinosaur - a little rounded, but not bad for a first try. I wanted to get more detail, so let’s try again!
Tried to do it slower and better-like, but my arm got tired and I would up with a bicephalic dinosaur. Cool concept, but not what I was trying to scan
I’ll take it! After a chance to rest and reflect, I managed to do this. I like how you can see some of the details in the teeth and such. Moral of the story: steady arm, good rotation, pay attention to how it looks on the screen as well.
Wrapping Up¶
Basically, 3D printing and scanning are cool concepts and when done right can be awesome tools, but a lot of the stuff behind the scenes getting it to that point could be better. Blergh. In the time of writing this, I probably have a couple more nozzles to clean.
Obligatory Dog Picture¶
