Printing double the size ... I think

Hi guys, my first post about my first 3D printer!

I've just built my reprappro ormerod. As a test a created a 4mm cube in blender, exported the stl file, ran it through slicr and printed it, and its coming out as 7.78mm cubed ... Are there any scaling settings I should be applying, or some other method I should follow to create my prints??

Cheers

Try another calibration cube: [www.thingiverse.com]
That one is 10mm cubed.

Typically if your e-steps values are off you'll get prints that aren't scaled correctly.

You need to calibrate your motors. This works by tell the system how much it has moved after telling it to move, sort of like a manual feedback control.

Here is a very good video teaching calibration done by engineglue: [www.youtube.com]

Btw, how is the print quality? It should be pretty bad if the print it scaled up twice. If not it might be an issue with the slicer.