MAE2250 offers teams the option to use the department's 3D Printing services on an OBJET Polyjet system or FDM systems (Dimension or UP!). Basic properties and prices are listed below. Please append "_OBJ", "_Dimension". or "_UP" to your file to indicate which service you would like. Prices are per single part or multiple parts submitted simultaneously in a single zip file.
Note: 3D-Printed parts are NOT food-safe certified by the FDA, unless printed in ceramics. Do not use printed parts in conjunction with food or drink. Wash hands after handling parts (see MSDS). If you are interested in testing 3D printed parts in conjunction with food, contact head TA for suggestions.
To request a 3D print, follow the following steps:
Prepare your part(s) in SolidWorks and "Save As" in STL format.
When saving, there will be an "Option" button when you can set STL parameters. Make sure that you save in millimeters (not Inches, even if you are designing in Inches). Be sure also to save at a high resolution. Save in STL Binary (not ASCII/Text). If you want to save an entire assembly containing multiple parts, check the box "Save assembly as a single STL".
Make sure your parts will be easy to identify when tossed in a box full of parts from other groups, or when compared to earlier versions of your own prints. It is a good idea to include in your design some kind of embossing with a serial number, mark, or other unique identifier.
Avoid printing lots of small disconnected parts - this will increase your cost and risk some parts getting lost. If you have many small parts, consider printing them as a single connected unit, in such a way that they can be easily broken off later.
Be sure to round (fillet) external edges (this saves material and makes your part look nicer), and round (fillet) all internal corners (avoids stress concentrations and makes the part stronger). Use a large fillet - as large as possible without compromising functionality.
Reduce unnecessary print material (and cost) by hollowing out large volumes, and perforating large sheets.
Avoid printing very thin details. Objet print accuracy is about 100 microns, but smallest printable feature is about one millimeter. If your team requires a part made in ABS for strength or flexibility, we can print it using the FDM system but this limits the smallest feature size to about 1.5mm.
Think organic. For example, if you are printing a cantilevered beam, make it thicker near the root where stresses are high, and thinner near the edges where stresses are low. Don't just print a uniform rectangular cantilever. Manufacturing complexity is free - complex shapes are not more expensive to print than simple shapes.
3D Printing material has about half the strength of ABS plastic. If you need to print a thin part that needs to be stiff and strong, consider leaving a small hole in its center so that you can later insert a strengthening screw.
If you need to connect your printed part to other components, consider printing holes where you can later insert thermoplastic inserts.
If you are uncertain about some portion of your design, print just that portion for testing, before printing the entire part. This will save cost and time, and will allow you to iterate faster. For example, if you have a large mechanism with an interlocking snap-fit buckle connector, print just to connector first to make sure you got the dimensions right, before printing the whole thing. You might even print three connectors with slightly different sizes.
You CAN print moving mechanism as a single part. If you do so, be sure to leave a gap of at least 250 microns between surfaces. You will need to clean out the gel between the parts, so make sure the gap is accessible. The surfaces will create friction of plastic-on-plastic when moving.
Name your files SectionTeam_Month_Day_ID_TYPE.stl, where ID is an optional ID number for you to use in case you must submit multiple files at a time, and TYPE is either OBJ or DIM or UPP. Example: "2A_10_13_1_DIM.stl" and "2A_10_13_2_OBJ.stl". (see section numbers - top left of sheet). Do not zip files - put each part in a separate file in the Box. If you are submitting multiple parts together, combine them into a single zip file and use the above naming convention.
Upload your file to the the shared MAE 2250 3D-prints Dropbox Directory (If you have not received an invitation, request it from your TA). Note that files will be deleted after use. Please keep a copy.
Collect your parts from a basket in the design studio (check a day or two later).
Remember to count your prototyping cost against your project allowance (even if it didn't turn out as you had hoped or you didn't end up using the printed part in your final project). However, when costing your product, you only need to count the cost parts actually used in the final product (use Shapeways pricing with the actual final product material you would use if selling).