The layer bonding is important and many materials are not so easy in this case. ABS, Nylon and some more can make problems if the temperature is low or too much part cooling is applied. This easy part is just based a two thin walls and shows you:
The small base between the cylinders help to keep it on the build plate, I do not adding any brim to my tests. This part is optimized for 0.4mm nozzles, for other sizes you have probably to scale it.
Have you seen my other easy material calibration part http://www.thingiverse.com/thing:1023717, downloaded more than 1,000 times so far?
Enjoy!
LayerCalib.stl | 287.4KB |