3D Printing

We have many 3D printers. All of them are fused filament fabrication (FFF) printers. A variety of thermoplastic filament materials can be printed, but not all available printers are capable of these.

All of Fat Cat Fab Lab's 3D printers were graciously donated or found. Special thanks to Matt Griffin of Ultimaker, 3D Hubs, SeeMeCNC, Emily Chapman, and Smooth Technology!!!

Certifications
There is no certification to use these machines. However, our 3D Print 101 class is recommended for first time users.

Materials
Members are encouraged to bring their own filaments for printing and store them in their bins when done. Below and above the main 3D printing table are various spools of 1.75mm and 2.85mm filament donated by others which are free to use. Any members who leave their spools out, by default, consents other members to use them at will.

Build Plate Preparation
Make sure build plate glass is clean and free of any oils or excessive glue stick by washing with warm water in the sink.

For best results for most materials, apply a thin and even layer of gluestick (two passes, cross-hatched, 0% overlap). Gluestick acts as both an adhesive and release agent (for thick layers) and the amount required is material dependent. For PLA and similar plastics, use two passes--too much is not good. For CPE & PETG, apply 4 layers for better adhesion and release.

Certain high temp materials will stick strongly to glass and can crack it. For those, it's better to remove the prints before the glass cools fully to prevent this (ex: PC).

Changing Nozzles
Ultimaker printers equipped with Olsson blocks can have their nozzles easily changed. Default for all applicable printers is 0.4mm (excludes Z-Unlimited). Please return printers back to 0.4mm after use or leave a note of what size nozzle is installed--nozzle size indicators are on the printers for this purpose.

The hot end must be fully heated and material removed prior to changing a nozzle, otherwise damange to the hotend and printhead will occur. The following directions must be followed for nozzle changing.

Directions:
 * 1) Select 'Material' > 'Change'.
 * 2) Once the material is removed, use the provided printed torque wrench and socket to unscrew the nozzle. The nozzle is hot so be careful removing it from the socket and place it on the table.
 * 3) Be sure the nozzle installed is debris free around the seat and threads.
 * 4) Install your selected nozzle only finger-tight at first. Wait 10 seconds until the nozzle heats up. This allows time for the threads of the nozzle to push through any residual filament in the threads for proper seating in the next step.
 * 5) Using the printed torque wrench and socket, fully tighten the nozzle into the heater block until you hear clicking (clutch slipping).
 * 6) Next, either load your filament normally or cancel the material change cycle.
 * 7) Level the bed. Bed leveling required after a nozzle change since all nozzles are different heights based on aperture diameter and/or wear.

Nozzle Sizes

 * 0.25mm - Greatest resolution, slowest speed.
 * 0.4mm - Best balance of speed and resolution.
 * 0.6mm - Faster speed, moderate resolution.
 * 0.8mm - Fastest speed, lowest resolution.

Ultimaker Nozzle Dimple Codes
Ultimaker nozzles are labeled with nozzle size and/or have dimples to indicate size. The following list only applies to Ultimaker brand nozzles. Other brands may use a different system.
 * 0.25mm - 0 dimples.
 * 0.4mm - 1 dimple.
 * 0.6mm - 2 dimples.
 * 0.8mm - 3 dimples.

Bed Leveling
Correct bed leveling is the most critical part to ensure successful print adhesion to bed. Adjust bed level and nozzle distance to thickness of Post-It paper (0.1mm). Dragging paper between bed and clean nozzle should have the pressure of "pencil on paper."

Ultimaker Instructions

Slicing
Ultimaker Cura is recommended for slicing files. It's a free and open-source slicing software developed by Ultimaker and is compatible with a wide range of printers from other manufacturers to custom builds.

Tips for Successful Prints
Watch the first layer or two before walking away from the printer. Check soon after that initial layers are adhering well before leaving printer alone.

Removing Prints

 * "3d Print Removal Tool" wood block. Slide along glass to knock print off glass.
 * Scraper. Can be used to peel up edge of print. Good for prints using Brim or Raft.
 * Tiny printed mallet. Similar to wood block for knocking print off glass.

Troubleshooting
For mechanical and electrical failures of the machines, please stop using the machine and notify the #3dprinting Slack channel with the issue.

Using the Z-Unlimited Printer
The Feral Printer was found on the streets of Brooklyn. It's found a new home with us and has been modified into the XXL Z-Unlimited.

Open Ultimaker Cura and go to "Settings" > "Printer" > "Add Printer" > "Add a non-networked printer" > "Custom" > "Custom FFF Printer". Give it a name, and click “Add”.

In the Machine Settings panel that opens, set these printer parameters:
 * X (Width) = 190mm
 * Y (Depth) = 190mm
 * Z (Height) = 1500mm

Do not enable heated bed.

Next, click the “Extrude” tab and set these parameters:
 * Nozzle Size = 0.8mm (or whatever is installed)
 * Compatible Material Diameter = 2.85mm

Important Information

 * It's not recommended to print anything other than PLA in the machine because it has no heated bed.
 * Make sure your filament does not have knots in the spool and that it is securely mounted on the spool holder.
 * Pausing a job before the extruder has cleared the bed-clamps will cause a collision.

Slicing Information

 * Try to keep the print hollow with 0% infill for really tall parts. But if you need to add infill, you usually don’t need more than 10% infill since the nozzle is a much bigger size

Maintenance
Some regular maintenance is required over time. Below are listed roughly in order by descending frequency of required maintenance/adjustment.

Nozzle Cleaning
Nozzles should be kept as clean as possible for best results. Outer edges of nozzle tip can be cleaned by wiping with PLA while the nozzle is hot. Innards of nozzle should be cleaned whenever there is blockage.

Axis Rod Oiling
All smooth rod axes should be and feel lightly oiled--never dry. Oil when nearly dry. Use light sewing machine oil. Never use grease! After oiling, with the printer off, move the print head slowly in circles across the full range of motion to distribute oil across rods. Don't forget to oil the smooth Z axis rods.

Lead Screw Greasing
This doesn't need to be done often. When the Z axis leadscrew is dirty or needs regreasing, wipe the lead screw with a paper towel to remove old grease. Lead screw should be re-greased (green grease, Magnalube). Spread a few drops of grease along the length of the Z axis leadscrew travel. It helps to use the advanced settings to ask the printer to move the bed up and down the Z axis to work grease into the threads.

Belt Tensioning
Belts should be taught. Loose belts will cause parts to be dimensionally inaccurate in one or more axes (X,Y). This can be viewed easily by printing a cylidrical shape with its axis in the Z-direction. Generally, the belts that need retightening will be the short belts from the X,Y motors. First pluck the belt and remember it's feel and sound. Loosen the 4 motor mount screws and push down on the top of the motor very hard as you retighten the screws in a star pattern. Pluck the belt and it should twang higher pitched when tightened.