Using CAD to create 3D-printable objects

While modeling, keep in mind the limitations of the printer. Try to avoid very shallow slopes, as the printer will have to support anything shallower than 45 degrees. Also remember that the top surface will have the nicest finish, while the bottom surface will have a rough finish due to the raft that gets printed underneath the part. Large, flat areas have the highest tendency to warp, and the larger the overall part is, the more likely it is to warp / peel at the edges.

thin, overhanging features will not print easily, or may fail entirely. Remember that there is a minimum width that the printers use (typically 0.4mm), typically you shouldn’t make things that are less than Four Times the size of the extruder (1.2mm).

Prints will often fail at sharp edges, or where a part transitions from wide, flat layers to skinny layers. use chamfers and fillets to reduce the chance of breakage.

comparison
Left: original part. Right: strengthened part for 3d printing

After modeling your part, ask someone knowledgeable in printing to look over the design. There are often small changes that can be made which will make printing / finishing easier, and it provides another chance to catch any errors.

Check out this PowerPoint for some more in-depth info