Syringe dosing unit

Almost completed design. Will be modified in future to solve notices below

14.11.2017 - were uploaded new models. Fixed some small issues
15.11.2017 - successful test with mine Arduino code. There are some future changes planned - syringe can be inserted from side, add sliding elements to middle part because printed one has some movement resistance, sometimes coupling is disconnected in way back- could be protected by small dowel (0.8mm) or purchased metal coupling from eBay
Good think is that arduino, motor driver and motor can be powered from USB only. So with that you can make a simple dosing unit powered just from USB or powerbank ;-)

Partlist
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- 3 printed parts + 1 printed motor coupling
- syringe , i.e. "BD" syringe, volume 20mL
- stepper motor 28BYJ-48 and driver electronics
- 2x M3 screw and nuts
- about 60-65mm M5 screw
- 3x sliding rods 175mm
- cca 60mm aluminium tube diameter 12mm , wall 1mm
- M5 nut is glued into aluminium tube, i.e. by