Most Common Parts that remain missing from LDraw

[Chris Böhnke]

This is a very interesting discussion, and I want to thank everyone for sharing their insights.  It does seem like the key concerns that impact a lot of parts are the issues of origin (I think this means the location of 0,0,0 center position) and the issue of orientation.  

I wouldn't be surprised if a predictable transformation gives a more acceptable orientation and origin, but I do now understand why this is a bit more manual than I would have hoped.  Perhaps a simple online tool where we could crowdsource the right origin and orientation might reduce friction for full integration into the collection at a later date?

---Tom

Whilst this should "mostly" not be an issue, I think orientation is more complicated than that. Orientation in LDraw is typically based on the concept of "part category" which can in some cases create a bit of disconsens.

Lego themselves don't help much here, as the category system they publish in things like LDD is an utter mess. Example?

Part 4266 ("Technic Hub Ø30.4 x 20") is listed as "Brick, Round" in LDD, despite clearly being a wheel.
Why?
4266's matching tyre got discontinued around 1994, however the hub was kept in use - mainly as motor housing for propeller planes up until 2004. LDDs database was likely made after that date, so they listed it as a round part (though it's not a brick either by any definition...)

Part 6797 (Technic Engine Air Scoop  4 x  4 x  1.333) is actually a Scala part, where it was used as a bin with an entirely different orientation.
Why?
Only few AFOLs around 1997-2003 were aware of the exact contents of Scala sets due to lack of interest. So when the part surprisingly appeared as a very visible decoration in a larger Technic set in 2001, many people assumed it was made for this Technic set.

Part catgories are often a very subjective thing and orientation is to a degree linked to it, just keep that in mind.