Syringe pump

I was looking for an syringe pump to automate the fertilization of my nano cube. My first try with http://www.thingiverse.com/thing:539490 failed. The mechanical part was not sufficiently stable. There are many syringe pumps projects at thingiverse but I decided to use the thing http://www.thingiverse.com/thing:536373.
Cause my printer has only a 80x80mm print bed this thing was perfect becauseall parts fits on my print bed.

But I've did some modifications so make the syringe pump works fine for me. There are some issues in the original thing:
* The distance of holes for the NEMA17 stepper are not OK. It is not possible to mount the motor.
* Cause the original thing is made as an extruder for a printer the motor holder has no holes to mount the syringe pump to a plate or something like this.
* At the syringe slider the shaft of the syringe is now fixed to the slider. With this its possible to push and pull liquids. This was important because I have to load the fertilizer then th