Colorado Mesa University

Engineering Specifications

Customer Requiremetns

  • Printer must be able to print chocolate lettering for cakes. - 30%
  • Lettering should be easy to input and have a variety of fonts. - 20%
  • Must be easy to sanitize. - 30%
  • Should handle one print job without being reloaded. - 10%
  • Font must be appropriate size for cakes. - 10%

Customer requirements were generated by speaking to a client in the baking industry.
All weights were determined by the client and used in the evaluation process to design the final product.

Updated Requirements

This comes from the customer There were no updates made to the original requirements. The requirements were kept the same as the customer was happy and content. The overall project as it stands meets the basic needs of the consumer. However our group always strives to improve upon its projects and go beyond the customer's requirements so future models and improvements are already being discussed.

Customer Requirements Met

  • Prints in chocolate
  • Has a variety of decoration applications
  • Easy to sanitize
  • Adequate chocolate volume and build area
  • Low cost

Engineering Specifications

  • Create a device similar to a conventional Fused Deposition Material (FDM) printer
  • Must have an extruder head that can properly position material on a print bed
  • The extruder must lay down molten chocolate in desired shapes such as lettering that is 1-3 inches in height and a width of half the overall height.
  • Will take conventional text files and convert it to machine code.
  • Chocolate will be stored in a clear 16 oz nutrient sterile reusable kitchen syringe

Specifications were generated by quantifying customer requirements.

Test Plan Outline

  1. How accurately can the print bed be moved around?
  2. Is the amount of backlash minimal?
  3. Can the syringe maintain a constant temperature?
  4. Is the printer dispensing a reasonable amount of material?
  5. How much chocolate can the syringe hold before weight becomes an issue?
  6. Can the printer produce shapes and letters that are within an acceptable range of error?

Tests to be Completed

  1. Move bed 1 inch and pause. Measure actual distance. Repeat for entrie build area.
  2. Move bed 1 inch. Place dial indicator on table. Move back .25 in and measure actual movement. Repeat 4 times.
  3. Temperature gauge will be set on syringe and measured for variation throughout the extrusion process.
  4. Volume per second will be measured as the feed rate. It will be evaluated for the jog speed of 10 mm/s.
  5. Head will be loaded with maximum chocolate capacity and measured for speed difference from being emptied. It will be in an acceptable range if it is within 1 mm/s difference in speed.
  6. The printer will be tested to an accuracy of 3mm.
  7. The chocolate will be tested to be at the correct temperature where it does not run onto the bed.
  8. The team will attempt to clean the printer after use to see the level of ease.

Testing Results


The image above is a link to the pdf version of our testing results for each axis