3D Printing
3D printing is a great way to prototype parts and perfect them before a production run, create ideal geometries that cannot be manufactured, make fixtures, patterns or molds and make parts with special material properties. Always assess whether you should make the parts using traditional manufacturing processes before 3D printing – for some designs subtractive manufacturing is preferred.
Our printers are available for use by the BU community.
There are currently two ways to 3D print at EPIC!
- Make a request through our web portal and we will print your project for you. We can help you choose a printer, material and settings as well as help catch features that might not be suitable for printing and slicing errors.
- For more experienced users on-demand FDM printing is available in person at EPC 101.
Frequently Asked Questions
What is an FDM printer?
Fused deposition modeling printers melt and extrude a filament of thermopolymer like ABS or PLA to build parts from the base up. Parts print on a raft, to help adhere to the print bed, and require dissolvable support or snap off support for any overhangs over 45°. Printers typically use a heated bed to improve adhesion and/or a heated enclosure to keep the temperature uniform while printing. Parts with dissolvable support will require a chemical bath after printing to remove support.
What is an SLA/LFSLA printer?
Stereolithography and Low Force Stereolithography printers use a basin of liquid photopolymer and a laser to cure each layer as the printer build parts from the base down. SLA parts require either snap off support or self supporting designs. A solvent bath after printing removes uncured polymer and a final cure in a UV light box completes the hardening process.
What materials can I print in?
FDM thermopolymers
Proprietary SLA resins from Formlabs
- Clear
- White
- Grey
- Grey Pro
- Durable
- Tough 1500
- Rigid 4000
- High Temp
- Flexible
- Elastic
What is the maximum build volume?
- SLA (Formlabs) 5.7×5.7×6.9 inches
- FDM (MakerGear) 8×9×8 inches
- FDM (Stratasys) 14×10×14 inches
What are the limitations of 3D Printing?
- In most cases the surface finish is not smooth. Even with LFSLA printers the snap off supports lead to surface defects.
- The parts will warp and shrink in ways that make the parts differ from your design.
- Printing is expensive and each person is limited in their budget for 3D printing.
- You cannot post-machine or modify 3D printed parts at EPIC. Specially designed fasteners may be glued into resin prints or heat set into FDM prints.
- SLA resin and FDM 3D printed parts are not recyclable and have a significant impact on the environment. PLA is biodegradable and may be composted by some commercial
composting facilities.
- Plastic 3D printing materials are not food safe.
- We cannot print parts to be used in devices that are subject to FDA regulations.
- You need to design your parts so they can be printed.
What tolerance should I use?
A comparison from best to worst…
- Computer Numerical Control (CNC), Machining – ±0.025mm to ±0.125mm
- Material Jetting/MultiJet (MJP)* – ±0.025mm to ±0.05mm per 2.54mm
- Material Jetting/PolyJet (PJ)* – varies with part size <100mm ±0.10mm, >100mm ±0.20mm, or ±0.06% of part length, whichever is greater
- Direct Metal Laser Melting (DMLM) / Selective Laser Melting (SLM) – ±0.08mm to ±0.10mm
- Stereolithography (SLA) – ±0.10mm
- Direct Metal Laser Sintering (DMLS) / Selective Laser Sintering (SLS)* – ±0.30mm
- Fused Deposition Modeling (FDM) – ±0.50mm
*EPIC does not have these, for comparison only
See also, Accuracy, Precision, and Tolerance Guide from Formlabs.com
How to prepare a part for 3D Printing?
Parts can be designed in any CAD software that can export to an STL file. Mechanical engineering students commonly use CAD software like SolidWorks, Creo or OnShape. Some designs may be more appropriate for FDM than SLA – FDM can print larger wall thicknesses in low infill and SLA always prints in solid so it requires thick parts be hollowed out or redesigned. All prints will be reviewed by a supervisor to check for appropriateness. We will send you back a message if we determine that we can’t support your request.
See also, video on how to use OnShape to optimize for 3D printing
How do I choose the best 3D printer for my part?
- Parts with volume over 150mL or wall thickness 1cm+ will be best on FDM. Exception being some geometries on the LFSLA Form3 may allow up to 350mL.
- Larger parts and parts requiring support along interiors that would make removal difficult are best on the Stratasys FDM printers with dissolvable support.
- Parts that require smooth (sandable) and/or watertight surfaces are best on the SLA printers. If parts have too much volume or cross-sectional area to print they can be hollowed out and a drain hole added (common for decorative items).
- Parts that require high temperature are best printed in High Temp SLA resin or PC-ABS on the Stratasys FDM F370 printer – or in some cases the high fire ceramic SLA resin.
- If we feel your print will work best on another printer than the one you’ve selected we will email you to discuss your options.
See also, Comparison of FDM to SLA from Formlabs.com
How do I choose the best FDM thermopolymer for my part?
How do I choose the best SLA photopolymer for my part?
- Clear: parts requiring transparency, fluidics, moldmaking, optics and lighting
- White/Grey: general purpose prototyping, presentation-ready pieces, very small features / intricate details, base for painted parts
- Grey Pro: Form and fit testing, mold masters for plastics and silicones, injection molded product prototypes, jigs and fixtures for manufacturing
- Draft: Rapid prototypes, initial design iterations, high throughput applications
- Durable: Squeezable prototypes, jigs and fixtures undergoing significant impacts, low friction assemblies and non-degrading surfaces, simulating the strength and stiffness of polyethylene (PE)
- Tough 1500: Prototypes that repeatedly bend and quickly return to shape, Jigs and fixtures requiring repeated deflection, simulating the strength and stiffness of polypropylene (PP), certified for permanent skin contact
- Rigid 4000: Mounts and brackets, thin-walled parts, jigs and fixtures, simulates stiffness of PEEK
- High Temp: Hot air, gas, and fluid flow, molds and inserts, heat resistant mounts, housings, and fixtures
- Flexible: Handles, grips, overmolds, cushioning, damping, shock absorption, seals, gaskets, masks, cartilage, tendon, and ligament anatomy (Note: we currently have the older version Flexible V1 not V2-80A)
- Elastic: Wearables such as straps, stretchable enclosures and casings, compressible buttons, soft tissue anatomy
Try the material selector tool from Formlabs https://formlabs.com/material-selector
How long will my 3D print take?
3D printing is a slow process the length of time the print will take is a function of the volume and number of parts, the infill and layer height selected for the print. Parts are queued with priority given to coursework. We recommend requesting your print at least 2 weeks before it is due wherever possible.
Please note we only have one PLA printer in the maximum build size (F370) so the queue will be longer for bulky parts that require our largest printer with the least expensive filament. Parts under 9″ in length will have a shorter wait.
Why was my print request rejected?
- The part could be more easily machined
- The parts are expensive to make
- The feature sizes are too small
- Requests that require large amounts of material ($50+)
- There are capacity constraints
- Parts are banned items (weapon related)
How can I scan an object for 3D printing?
We don’t currently have a high quality scanning method at EPIC so we suggest trying Photogrammetry! Read on for some software options to try…
- AutoDesk ReCap Photo, bundled with ReCap Pro. This is only available for Windows users.
- As an EDU user, you get ReCap Pro and ReCap Photo desktop apps free. You are, however, limited to 100 photos per project for cloud processing. Visit AutoDesk to make an EDU account and download ReCap Pro at autodesk.com/education/edu-software.
- When taking photos use a high resolution camera, keep your object stationary and move around the object as you take images of it from all angles. Select only images with good lighting and focus. Do not change the lighting on the object as you take the photos and do not use a flash on the camera. Shiny objects are difficult to scan.
- Meshroom Available for Windows and Linux users alicevision.org/#meshroom
- AI Scanner from MakerWord Check out the “shooting guide”, take a video and upload to the website https://makerworld.com/en/makerlab/ai-scanner
- LiDAR based scanning apps Available for Apple iPhone or iPad, check the app store.
After the data is processed (this may take a long time!) you will receive a mesh file to download. The mesh file usually needs some editing to get to a printable stage. There are several free software packages that you can use to edit mesh files.
For a fun app that turns a photo into a 3D Relief checkout MakerWorld-Relief Sculpture Maker
https://makerworld.com.cn/makerlab/reliefSculptureMaker