- This machine should not be operated without induction.
- This machine should not be left unattended during operation.
This 3D printer is an Ultimaker 2+ that belongs to South London Makerspace. It is a Fused Deposition Modeling (FDM) machine used for Additive Manufacturing/Rapid Prototyping. This machine should not be left unattended during operation.
- Manufacturer: Ultimaker
- Build volume: 223 x 223 x 205 mm (considering the clip holding the glass the maximum depth usable is around 210mm)
- Resolution: up to 20 micron, lower resolution 320 micron
- Nozzle temperature: 180ºC – 260ºC
- Bed temperature: 50ºC – 100ºC
- Nozzle diameter: 0.4mm
- Filament diameter: 2.85mm
Donated in new condition November 2014.
- PLA, PLA+ / Tough PLA
- TPU allowed but not recommended because of Bowden extruder.
PETGshould not be used because it can damage the glass bed.
Description of task
Making three dimensional objects from a digital file. The creation of a 3D printed object achieved using additive processes. The object is created by laying down successive layers of filament plastic material until the entire object is created.
Identification of hazards and risks
- Harmful or toxic fumes – Low
- Burns to fingers or hands – Low
- Fire – Low
- Entrapment in moving machinery – Low
- The SDS for the filament material used in the 3D printing process states that there is no harmful levels of chemicals in the fumes, and the fumes are not considered an irritant. General ventilation is however advised. This should be reviewed for each new material used.
- The risk of burns is reduced because exposed hot area is small. The temperature of the hot end is typically around 210ºC, which can cause an unpleasant burn, but does not pose an extreme risk.
- To reduce the risk of fire the Ultimaker should only be operated when an inducted member is present in the area and aware of it’s ongoing operation.
- The motors in the Ultimaker are relatively low power, and unlikely to cause serious injury, however long hair or loose clothing could be pulled in, although the machine is not likely to cause serious injury and operates relatively slowly, leaving time to react and turn it off. Also there is signage on the machine and the wall next to the machine indicating the presence of this risk.
- Ensure machine is clear of any debris from previous prints or dust collection.
- Ensure Cura slicer machine setting are setup to an Ultimaker 2+
- Machine should not be left unattended for long periods of time.
- Machine should only be used with Material listed within the Approved Material list
- Do not change the default material settings on the machine but do it in slicing software.
- Remove your filament using unload procedure.
- If you used any other material than the recommended PLA you’ll need to flush the nozzle.
- Ensure machine has been switched off and unplugged.
- Clean any waste material up.
- Put back the machine cover.
To use this machine you should undertake a short induction held by @3dtechs.
These members may choose to charge a small fee for their time and materials of up to £5 per user, and the induction will only cover the operation of the machine, further assistance on how to use 3D software, or do other tasks is not covered in the normal induction.
What the induction will cover:
- Introduction to who you are your interests/expertise.
- Explain the core concepts of how a 3D printer works and it’s limitations (overhangs, tolerance, circles/holes).
- Discuss risks. Highlight the possible ways an accident could happen and what to do.
- Explain about different filament types, highlight that we only use PLA at the moment in the space. What to buy, and where to buy it.
- Demonstrate how to load and unload filament from the machine from the menu.
- Demonstrate how to slice files using Cura and load them onto an SD card.
- Test the inductee by asking the user to print a small part.
Part 1, Risks:
- Burns – Indicate the hot areas (nozzle, bed and motors) of the machine and their typical working temperatures (220ºC/60ºC respectively). Advise if a burn does happen to immediately put the burned area under cold running water for 15 minutes and seek assistance from another member immediately.
- Entanglement – Highlight the risk of getting hair, fingers, or clothing caught in the belts, motors and other moving parts in the machine. Advise of the location where the switch is.
- Fire – Advise not to leave the machine unattended while in operation, such as leaving it over night, or going out for food. Ask someone else to take responsibility for monitoring it, or pause the print. Advise the use of a CO2 fire extinguisher if a situation arises as the machine is an electrical device.
- Respiratory – Advise that the fumes from PLA are not anticipated to cause any respiratory issues, but that before using it is worth advising other members you are going to use it so they may move, or ensure they have medication for their condition (asthma).
Part 2, How FDM printing works
Fused Deposition Modeling (FDM) works by melting a thermoplastic, such as PETG or PLA, through a nozzle and depositing it layer by layer to create a 3D object. The material is fed through a heated extruder, which melts it to a semi-liquid state, and then drawn onto a build plate according to the 3D model’s specifications. The build plate moves down by a fraction of a millimeter (layer height) after each layer is printed, and the process repeats until the object is complete. The printed object is allowed to cool and shrink before it can be removed from the build plate (important!).
Tips for easy printing:
- Lay your model on it’s largest surface area (and call it the bottom surface). A large, smooth, round shaped surface is best.
- You might have to rotate and cut downloaded models to create a good bottom surface. This is possible in the slicer or CAD software.
- Avoid sharp corners on the bottom surface, when the plastic shrinks slightly they will detach from the build plate.
- Avoid long and narrow objects unless both ends have enough surface area to keep them attached to the build plate. Otherwise as the parts cool and shrink, they will pull the ends upwards and separate from the bed.
- Walls can print well vertically down to an angle of 30 degrees from horizontal (overhangs). Any more horizontal and the plastic will droop, and will need to be supported.
- Bridges (printing horizontally between 2 parts of the model) up to 40mm work well, longer bridges will have noticeable plastic lines or might fail.
Tolerances for printed parts are usually±0.1 millimetres. You should offset or push outward the surface around bearings or other parts by 0.1mm for an easier time assembling. There are options in the slicer software to automatically expand holes by a certain amount in the XY plane.
Many functional prints require assembly, there are a few options to join parts together:
- Pegs. Some slicer software allow you to slice large 3D models and add holes and pegs for easy fastening (like Ikea furniture).
- Snap joints. You’re using plastic so you might as well use all its properties! You will likely need to design snap joints specifically for each part. This is a good guide for designing buckles and snaps.
- Nuts and bolts. Extrude cut a small hexagonal pocket for a nut (M3 size works well) and fasten it from the other side with a bolt.
- Heat set inserts and bolts. These are an elegant way of adding threads to the faces of parts, especially if accessible from only 1 side. You can use a soldering iron to heat a threaded insert and push it into the part, it will remain rigidly embedded in the part when it cools down.
Part 3, Filaments
PLA is the easiest plastic to print with and modern formulations have good strength, particularly PLA+ or PLA tough variants.
- + Easiest to print. Good bridges, good on overhangs.
- + Somewhat biodegradable.
- - Melts in the sun.
- - Degrades over time.
- - Shatters when it breaks.
PETG (PET glycol) is an alternative to PLA, but ideally printed on a PEI plate (use the Flashforge dreamer).
- + Higher temperature resistance.
- + Slightly elastic; yields before breaking.
- - Pain to print sometimes.
TPU, or flexible filament, for your bendy needs. You shouldn’t print this with a bowden extruder (use Flashforge dreamer).
- + Really bendy.
- - Difficult to print and leaves a lot of stringy residue from retractions.
- Beware that TPU is not rubber, it’s still slippery.
Part 4, How to Print
- Get STL or 3mf file from you CAD software, or 3d model website like printables.com.
- Open slicer software (Cura for Ultimaker, flashprint for Flashforge). Ensure you select the settings for the machine you intend to use (top left corner of the screen in Cura).
- Drag and drop, or open 3d model in slicer.
- Arrange model orientation (in Cura you can use the Rotate submenu located on the left side of the screen).
- Slice, and preview (in Cura the Slice button is bottom right side, and Preview is located in the top menu).
- Preview using the layer slider on the right side of the screen and check if you need to enable supports.
- Save to disk. Save .gcode file directly to the SD card, via the USB card adaptor.
- Turn printer on, insert SD card, check there is enough filament.
- Select Print from the printer menu using the round button, then select your file.
- Wait until the first layer is printed, carry on if it looks smooth and flat, restart the print otherwise.
- Wait for printer to finish and a few minutes for the print bed to cool down.
- Part will detach when print bed cools down, use the bed scraper gently to help it release.
Part 5, Common errors
- If the first layer doesn’t stick well, try printing again. It usually fixes itself because the residue from the previous try helps with adherence.
- On the 3rd try, clean the bed with IPA alcohol and tissue, or wash with dish soap.
- Re-level the bed if one side prints fine but the other doesn’t, also do this is if you removed the glass surface from the printer for washing. Follow the instructions from the printer menu.
- If you hear creaking noises from the back, the filament might be stuck! Pull out the filament to untangle it and put it back in by following instructions to change filament from the printer menu. You might have to cut out the damaged part of the filament and discard.
- Tall and thin prints might topple over at a certain height. The nozzle drags on the surface of the part as it prints, if there isn’t enough surface area sticking to the bed, it’s easy to detach. Consider enabling a brim, or adding a thin base to your model. In Cura the setting is called Adherence.
That’s it, Happy Printing!
The induction giver should post the names of the inductees in the tool access control thread.