3d model Syringe Servo Pump Injection

Remix of the original syringe pump. I liked the simplicity and robustness of the original design, but wanted to improve on some key aspects: -Unibody design. -Better sized for a standard Tower Pro MG 996R servo motor. -Twist lock for syringe, removes need for zip tie or other fasteners. -Reduced moment arm between rack and syringe piston. -Syringe piston bracket uses 3mm screw for improved strength/reliability. -Mounting holes/flanges to secure the assembly with some m3 fasteners Some areas that could still be improved in future iterations: -The pitch of the rack and pinion seems to make the travel for a 180 servo too long for a standard 10cc syringe. Ofc this can be accounted for in the software, but u leave some additional torque on the table as well as the possibility to overstress the parts if you don’t realize this and put the necessary software stops in there. -The Pinion gear could use a little more of a nuanced mating hole. Would prefer a blind hole to mate against the end of the shaft on the servo so that it can be locked into place with a fastener instead of just relying on a press fit essentially. To assemble: 1) Thread screw through rack hole and into syringe piston bracket. Don’t overtighten. but remove as much play as possible. I used a 10x3mm plastic screw for this. 2) Install syringe and lock flange into place with a 90deg CW motion. Then slide syringe piston into syringe bracket and allow rack to rest in the channel. 3) Slide the piston all the way to the end of the syringe so that the plunger is at the 0cc marker. 4) Install the pinion gear onto your servo and slide the servo into the bracket with the gear closest to the flanged side of the syringe. *Make sure that your servo is at the end of it’s travel in the correct direction. You can test this by rotating it by hand. The servo travel should roughly match the piston travel. 5) Screw in the 4 x m3 bolts (I like to use plastic screws for this) to secure the servo into position. You’re done! If you like the design or find it useful, tips (even small ones) are always appreciated! 🙂