Lego© compatible 2x4 Block

FINAL UPDATE / Statement (18/01/2017 17:00): Three white 2x4 reference blocks just came out of my printer:
- Base
- +0.25
- +0.5
It works like that: you print ALL three blocks in your desired color, resolution and
density. Than you drive in the knobs with an original circular single brick.
Next you check various blocks and positions. Than you choose your desired flavour
which is 'engraved' in blocks

All my further designs you will find all three flavours for your choice. If no flavour fits, give me a feedback. The clip holes should be no problem as you can open them up with a 4.8 mm drill if too narrow.

Last but not least I would to thank 'snewpy' for his feedback to develope this latest version of a 2x4 Block! http://www.thingiverse.com/make:288389

About printing Lego blocks, you have to deal with a couple of challenges:

[1)There are 4 different Lego clip types:
- Tube clip => will brake
- Rod clip => will brake
- Square clip => well...
- Hole clip = my cho