For a future project, i'll need accurate 3D prints.
To test outside dimensions I printed the 20mm hollow box from: http://www.thingiverse.com/thing:52946
Seems good to me!
A few settings were changed: reduced temps to 195° and flow rate to 70%
The default values are a bit too high.

The upper end of the z-axis threaded rod is not really clamped on the Vertex K8400 3D printer.
To improve this I printed a design from thingiverse and ordered a 608 bearing.
This mod should reduce vibrating sounds coming from the z-axis and improve print quality.

3D printer demo day. Pictures and video.
Mostly Velleman Vertex K8400 printers.
Also homemade 3D scanner present.

After spending severals hours a day building, I finished this kit in about 7 days.
I did not timed it exactly, but I think i've spend close to 30hrs from unpacking over building and calibrating to the first print.
Didn't encountered many difficulties, thanks to the good manual.
A few remarks:
Some places were a bit difficult to reach, but with a little patience everything works out.
I also had to adjust the X and Y clamps a bit to make the movement really smooth, some extra oil helped also.

Yesterday my 3D printer arrived.
There are many parts in the box and it's a lot of work to build it, but I like that!
You can watch a live stream of the build on http://www.twitch.tv/bgprojectz
Hope to see you there!