The project has been successfully completed! The SpiceRight spice dispenser is now a real thing and it works quite well.
The 3d print went really well, the gear pieces came out looking like this:
The only issues here were that the holes on the small gears were too small (I sanded them out) and the snap fit pieces didn’t work at all. This was initially a huge problem I faced, but I found a solution pretty quickly with some tinkering. I put some tape on the joint of the snap fit pieces and this allowed the gears to snugly fit on and turn smoothly.
The gear lids were glued to the spice container lids with no issue.
The servo motors were glued to the back of the arduino, along with some cardboard supports – the idea being that the motors and these supports create a middle section of the device so the motors can be better tucked away.
The housing went on nice and easy and looks great. It has a slight texture that makes it easy to grip.
As I suspected, I had to calibrate the motor turns a bit in Arduino to get them opening just the right amount for each spice to dispense decently well. Actually the pepper flakes still didn’t dispense really well – it’d be better if the motor could turn a bit more or if the gear ratio was altered.
From the physical standpoint, the only thing the device is lacking that I had really hoped to implement was an easy switch system for different spices. Based on how carefully the gears have to align I couldn’t figure this out in time and opted to instead secure these two spices to the device.
Also the cord gets in the way a bit… bluetooth communication would be better for a future model, but I didn’t really expect to get that working for this.
From the software side, there’s 214 lines of code running in Processing that creates the user interface and records the dispensing times. The G4P library I downloaded and used was essential. I initially found it just to be able to more easily implement buttons and other GUI features, but it also had a timer function that made it really easy to time the opening of each spice container. Writing the code so that it would accurately record these times and recreate them was a big challenge for me, but through trial and error I got it working eventually. Discovering the timer function within the G4P library was also a big saving grace.
The Arduino code is pretty straightforward. Its 58 lines of code that really just receives serial messages from Processing and opens/closes the lids accordingly.
Processing and G4P made designing the GUI quite easy, and I am very pleased with the result.
I was able to complete this project successfully and make it fully functioning. Having said that, there are some areas left dive in to with a future version – bluetooth and removable containers.
I learned a lot about 3d printing from this project as it was my first (successful) 3d print. The level of detail the printer can manage is less than I expected, which is why my snap fit design failed.
Both this course and this project also taught me a lot about what goes in to physical design. Creating something that looks good, properly houses the machine components, and is easy to use is a very difficult task.
Finally, here’s the SpiceRight in action:
eidophysicalcomputing 