Sometimes 3D model parts need to be attached to each other for various reasons:
- Printing area not large enough.
- Visual effect alternative to printing in multiple colors, desired 'inlay effect'.
Of course, there is no reason that just one of these is used in one case. If two parts are designed for each other, they are likely already interlocking to some extent.
Such as magnet joints.
Stuff that clicks together, often with little pegs that bend a bit. Note(again) that really small stuff tends to be much weaker along the directions of print.
Disadvantage is that you need to put a clamp in the design.(But maybe you can choose an existing one) Plastic-based springs are okay, but not so good under constant tension, as they creep.
bolts and screws
metal bolts and screws
Most RepRaps and RepStraps use a bunch of metal nuts and bolts and threaded rod and washers to hold things together.
printed plastic bolts and screws
Large enough threads are printable, so things can be screwed together. You have to get both the positive&negative threads correct to have it hold on properly. Things like the ScrewTopPot. "Fully printable PCB vise"; "3D Print Any Nut or Washer"; "printing threaded things like screws, screwcaps"; "Nut, Bolt, Washer and Threaded Rod Factory"; etc.
More discussion about printed nuts and bolts: Wanted Objects; "Printing nuts, bolts & screws - Is it possible?"; "Nuts, bolts and other fasteners"; "Any experience with printing threaded parts?"; "Designing and 3D Printing Threaded Parts"; etc.
The wedge-together system used on the Holliger ...
Screws and nuts are a straightforward and easy-to-get-decent way of connecting things. Disadvantage is that the Vitamin 'screw' has different lengths and sizes, making it less convenient.
Advantage is that it is easy to control the tightness. (Many uses, for instance locked nut to set something at some particular distance)
A cable tie, also called a zip tie or a tie-wrap, is designed to hold cables and wires together.
Most RepRaps and RepStraps use lots of cable ties, also called zip ties or tie-wraps, to help manage the wiring. A few use cable ties for more critical parts of the structure.
Using (rigid)metal wire(See Roping for flexible wire), can sometimes be used when something was designed for screws.(But obviously much scrappier) Usually it is more convenient to lay the wires closely in parallel before twisting them together. Note that bends often dont pull out easily so it is better to have all the wire layed out nicely before putting it under tension.
Wire is usually a present vitamin, and you can easily cut off different lengths, and it is easier to fit into designs than screws. Disadvantage is that the wire may rust, and the methods are more tricky. Also, note that if there is any give and it wobbles, it will fail eventually!
Tightly interlocking parts
These can take quite a bit of force to compress together, in some cases needing a pipe wrench.
Advantage is that it doesnt take any vitamins, disadvantage is that it needs to be designed in.
See Glue.(It is rather too terse at the moment)
Also epoxy granite.