Drafting with printing in mind part 1: Tolerances

If you draft the model for viz only and are then asked to get a print of it, there are likely going to be a variety of problems with getting your model in to a printer, but it is doable. The conversation on "how to adjust my model" is unfortunately fairly specific to the model at hand, but there are helpful best practices that can be found in many of the Books for the software you are using.

If you are starting with a blank slate and draft the model with printing in mind, you are in a much better situation and can save considerable time. I would suggest, if your office frequently prints models, you draw every model with printing tips in mind. The following are my suggestions for drafting with 3D printing in mind.

Step one:

Determine the minimum thickness needed for fragile (unsupported) parts. To do this I suggest contacting whoever will be in charge of running the machine you are printing on. For our Z Corp 510s I use a min thickness of .05". Next we need to back out a "real world" dimension by choosing the most likely scale we will print at. I do a ton of 16th scale pieces so I will use that as our example.

.05" (min thickness) X 12 (feet to inches) X 16 (chosen scale) = 9.6"

So all of my freestanding posts, columns, roof overhangs, trusses, etc. will be drawn at 10" (always round up to be safe and save time)

Obviously you can not render your model with oversized detail pieces so this is where drafting with 3D printing in mind deviates from drafting for viz alone. You can draw your accurate detailed part, a roof for example, and then draw over the roof with a de-featured and oversized roof. Place the oversized roof part on a new layer "3DP roof". You can then turn off the oversized roof and continue to work normally without having to make any significant changes when the boss-man suddenly wants a print.

After you have adjusted your model's details to meet 3D printer tolerances, see Drafting with printing in mind part 2: Holes and Gaps