3D printers
FDM Printers
How FDM 3D Printing Works.
For this example we’ll use a Dimension ___ , manufactured by Stratasys. It is a Fused-Deposition Modeling system, and this is how it works: After a 3D model has been designed and exported to an STL, a special program slices it up into cross-sections thick. It looks at each cross-section and generates a set of instructions on how to build it. When this information is sent to the printer, it starts with the bottom-most layer, laying down plastic in the shape of the cross-section. When it finishes the first layer, it moves up a slice to start on the next layer. Take a close look at a 3D-printed model and you’ll notice that it is actually stepped. The machine consists of a moving bed (Z-axis) and a print head (X-axis and Y-axis). The print head has a heating element in it; thermoplastic is forced into the print head, melts, and is squeezed out, not unlike toothpaste. The print head is calibrated in such a way that the molten plastic coming out of it is almost always the same thickness. In order to form complex shapes, overhangs, and hinges/joints/free-moving objects, the plastic needs to be held up by something. The machine prints using a second material, which we call the ‘support.’ When the print is done, it is put in a bath of solution that dissolves away the support material, leaving only the finished model. Some machines do not have a second support material an instead have supports generated in the model material when sliced.
Dimension
The Dimension SST 1200es I operated at UArts was a lemon. Material was the main culprit, but it was also an abused machine before I got to operate it. The 170 is okay, but when you print you’re literally burning money.
Ultimaker
2+ Connect
Quite a good machine. From my own experience with various printers, this is the buy. I’d get one for myself if I needed one!
Lulzbot
Overview
Great printers.
- Lead Screws Lubricated (December 2019)
- Need firmware updates.
- Material Sample Test for Tolerance
- Benchy off of each printer
Printer Quirks @ NVD
Printer 1
- Y Belt Issues
- Has some nozzle contact issues on calibration.
- Needs new PEI.
Tolerances for 1x1x1 cube test: X Y Z
Printer 2
- Y Belt Issues
- Has some nozzle contact issues on calibration.
- Needs new PEI.
Tolerances for 1x1x1 cube test: X Y Z
Printer 3
- Y Belt Issues
- Has some nozzle contact issues on calibration.
- Needs new PEI.
Tolerances for 1x1x1 cube test: X Y Z
Printer 4
- Y Belt Issues
- Has some nozzle contact issues on calibration.
- Needs new PEI.
Tolerances for 1x1x1 cube test: X Y Z
Monoprice Maker Mini V2
Decent printer that I use at home directly off my PC with CURA. May set up Octoprint once I have a good location for the printer.
Monoprice Maker Select
Run away from these fire-hazards. Even after fixing the thermistor…
Makerbot
Replicator
Solid machine, likes loose extrusion, hard to keep consistent temp. Once it gets gremlins they stay.
Replicator 2
Horrible machine, all I have interacted with have had ribbon cable gremlins. Run away.
Replicator 2X
Really decent when they work. Can be very temper-mental. Does two materials well.
Plastic Recycling Research
- Recycle Bot
- Precious Plastics
Materials Review
- NGEN is great, but fractures, super shiny.
- PLA, good-old standard. Watch for moisture and dust.
- ABS, only for enclosed dimension, very susceptible to moisture damage.
- Ninjaflex, only used once. Can’t use at home.
- TPU, want to try.
SLA Printing
Form 2?
Super interesting printer, not student friendly. I spent 2 months servicing one that a student almost broke the year before I got to NVD. Definitely get a good UV box or clean sunny space. There is actually a horrible design flaw in the spring connectors between the printer and the resin basin…
- Inventory Material
- Write up checklist for proper handling
Shapeways Printing
Sandstone Printing
Done through shape-ways, link image from minecraft!
Ceramic Printing
Done through shape-ways, link image from Ryans gift!
Notes that need to get added into above or gcode…
Working with Tolerance and Support Material.
There are a few basic guidelines to follow when developing a model for printing. These won’t help you edit a model; these are things to keep in mind when designing it.
Wall Thickness - The printer can print walls as thin as ~0.01”, however these will not be structurally sound. Keep walls to a minimum of 0.04” for rigid structure.
Suspended Parts - It is possible to make joints by leaving some space between two interlocking parts; leave at least 0.02” or the printer may connect the two parts. If a part is threaded or must fit snugly, it is best to print it separately (when possible).
Model Interior settings:
Solid: fills any interior space with 100% plastic. Strongest and most expensive option.
Sparse High Density: fills interior space with a grid pattern. Very strong and cheaper than Solid fill.
Sparse Low Density: fills interior space with a grid pattern using less plastic than Sparse High Density. Uses the least plastic and is therefore the cheapest.
Support Fill settings:
Minimal: uses the least amount of material and is therefore the cheapest option.
Sparse: uses more material than Minimal. Only necessary when printing complex overhangs or objects that require a high tolerance.
Printer Capabilities: