LDraw.org Discussion Forums

Full Version: Comprehensive guide to brick sizes
You're currently viewing a stripped down version of our content. View the full version with proper formatting.

I am aware that this message should probably go to a different address, but it seemed the easiest to find.

You may be interested in inspecting two pages I just produced:




especially the bottom part of the second page as it refers to LDraw.
I hope it sounds more positive than critical.

There are also pages on Duplo
but they are not connected to this subject.

Best regards,

Robert Cailliau
Note the section on technic hole offsets which clearly illustrates the fact that our technic holes are in the wrong place, even according to our rounding.

An interesting dissertation, but Agh!!! - the old 0.4 mm vs. 1/64 inch discussion, yet again.

Robert Callliau Wrote:However, the remark on real world approximations given on that page is wrong: at room temperature 1LDU is certainly exactly 0.4mm, and the value 1/64 inch is certainly wrong. The LDraw brick models will nevertheless work fine between themselves. They are approximations of the real bricks, as I argue below, and in the C4D models I make for myself I also use some approximations.

The original (British) design by H H Fisher Page for Kiddicraft used imperial measurements.
I like the guy's methodology! Thanks for showing us.
1. That article is hard to read on 1080p monitors. Sad
2. I would have preferred to see Imperial measurements next to his metric ones.
3. Are we supposed to switch over now that he has posted his article? 1/64" is so much simpler.
4. What measurements does LDD use?
The difference between 0.4mm and 1/64 inch is 0.008 LDU. The ostensible tolerance on bricks is 0.06 LDU. It doesn't matter.

This has always struck me as an attempt by the two countries that have kept a patently stupid measurement system for historic reasons (OK there are others, but they barely have internet) to assert some claim on measurements. Why don't we follow the language rules and declare that everything uses Australian units (since Australia is not on of those two countries, that means metric).


P.S. Tongue slightly in cheek here. But slightly not.

edit: that should have read "mostly in cheek"
"The ostensible tolerance on bricks is 0.06 LDU. It doesn't matter."
A BIG +1 !!! And I agree to use Autralian units...
I plead for the Swiss unit system ... fortunately it is the same as in Australia :-)
I just loved reading this.
I loved the appreciation for LEGO's engineering which shined through the whole text.
And I loved the love for the Duplo trains, coming from an adult perspective.