Design a 3D model of spice mill

Hi, I would like to find a designer to help me design a mechanism for a special simple spice mill, get a 3D model, and print it using a 3D printer. The idea: I would like to have a tube with diameter of around 2cm. Using servomotor (placed on top of the tubex), it should throw out a specific constant volume of spice for each full cycle made by the servomotor. This volume should be what is equivalent to quarter gram of mashed pepper. The spice should be already grounded. The challenge: Getting out the same constant volume is very important and precision is very important in this project. The mechanical movement should be done using servomotor and should be as simple as possible. The deliverables: 1. Very preliminary design of the tube, the mechanical movement to release the spice, a short describtion of how it should work. We make some modification and proceed to next step 2. First version of the full design, we could make some changes until we agree fully on the design 3. 3D print of the product, test it and send me a video of it working. (servo motor is not essential here, a hand movement is acceptable). I will pay for the printing of the product. 4. Deliver the 3D model in acceptable 3D file format.