Thanks to the help I’ve got here and a combination of openSCAD and the Wikipedia article on Legos, I can now safely say that this printer gets all dimension right. The full-height pieces printed reasonably without support and have a good enough fit that I can lift this contraption holding any of the white pieces.
Oh, and now I don’t have any more reason to avoid certain shapes of roofs on my Lego buildings, with a 3D printer and a parameterized .scad for single and double slope bricks 
We couldn’t get LEGO-compatible blocks to print that well with a low-end Stratasys. Good work!
Links?
@Hannes_Lilliefeldt That link doesn’t work for me - is it because I don’t have a youmagine account?
@Patrick_Ryan
Sorry, I hadn’t figured out I had to press the “Publish” button after uploading and pressing the “Save” button. I’m new to youmagine, just a few hours ago I promised @ThantiK to take a look.
@Hannes_Lilliefeldt Thanks, that’s done it. I’ll have to try that out when I get home on Sunday!
Cool Lego upgrade pieces. Good luck with things if they ever decide to harass you about it. Oh wait…“Since the expiration of the last standing Lego patent in 1989…”
You may be perfectly safe unless they decide to harass you about saying “Lego” on a page or not having a “TM” next to it or some crap like that.
Will the design be on Thingiverse and any (list please?) alternatives?
@NathanielStenzel there are already so many commercially available compatible clones that Lego has stopped using the knobbly pieces in their technic sets. My .scad source is on youmagine. There are enough Lego bricks on thingiverse, as mentioned above.
