Robust Doctoral Hat Mortarboard Doktorhut

In Germany there is a tradition of decorating mortarboards for the defense of a doctoral candidate:

When a doctoral candidate successfully defends their thesis and is awarded the doctoral degree, they have the privilege of wearing the "Doktorhut." The Doktorhut is a special version of the mortarboard, usually made by colleagues of the research group. It is not only distinct in its appearance but also holds playful and personalized decorations on top.

There is a unique tradition of decorating the Doktorhut with playful elements, such as Playmobil figures or other small objects. This tradition allows colleagues or friends of the doctoral candidate to contribute to the celebration by adding decorations that represent the candidate's interests, achievements, or funny stories. These decorations are carefully selected and added to the Doktorhut after the successful defense of the doctoral thesis, symbolizing the completion of the academic journey.

The personalized decorations can include small figures, symbols, or objects that hold special significance to the candidate. They are often representative of the candidate's hobbies, notable achievements during their research, or other memorable aspects of their academic journey. The added playful elements contribute to the festive and lighthearted atmosphere surrounding the achievement of earning a doctoral degree.

As these decorations can get too heavy for a velvet mortarboard, often more robust doctoral hats are built by collegues and friends. As I worked in a group with many doctoral candidates for some time plus having a 3D printer, I came up with a sophisticated and comfortable design.

BOM:

• Special Parts:
  • https://www.schacht-berufsbekleidung.de/p/delta-plus-ersatzgurt-harness-v-fuer-bauhelm-diamond-v 
• Printed parts:
  • 6x stange
  • 1x Base
  • 1x top inner
  • 1x top outer
• Hardware Store:
  • 1x M5 Nut
  • 1x M5 Countersunk bolt (M5x14 to M5x20)
  • 3mm MDF plate (e.g. 33x33cm)
  • Superglue (Cyanacrylate)
  • Double sided sticky tape.
  • Construction paper, black (Tonpapier) with 500x700mm

Instructions: 

1. Assembly of the Base:
   1. Begin by printing all the parts. Use a layer height of 0.2 or 0.15 for the six "Stange" parts, and 0.3mm layer height for the rest of the parts.
   2. Once the parts are printed, assemble them according to the provided photo. This involves combining six "Stange" parts, one base, and one top inner part. Use a small amount of glue to secure the connections.
   3. 
   4. Prepare a piece of paper measuring 700x155mm. Attach sticky tape to one end of the paper.
   5. 
   6. Place the paper into the gap on the base part, ensuring that the overlap is positioned at the back. The front of the hat should align with a small recess on top of the ring. Push the paper all the way into the gap.
   7. Attach the top-outer ring to the assembly. Apply a small drop of glue through the holes or use small screws for additional stability.
   8. 
2. Assembly of the top plate:
   1. Now, take the MDF plate and apply sticky tape to the edges.
   2. Drill a 5mm countersink hole through the center of the MDF plate.
   3. 
   4. Use the sticky tape to mount the paper onto the MDF plate.
   5. Cut the paper around the edges using a knife. The OLFA knife from Prusa is recommended for this task.
   6. 
   7. Open the paper at the location of the hole, using the knife.
   8. You could now mount the top plate to the base with an M5 Coutnersunk screw and the M5 Nut, However, it might be easier to do that as a last step, after decorating the rest of the hat
3. Insertion of the Harness
   1. Assemble the Helmet Harness so that it looks like in the following photo. Pay attention to the exact position of the bolts to the holes( the bolts should be clicked into the lower of the two holes in all 6 parts
   2. 
   3. There is a small piece of plastic in the very front. Just remove it using a knife or a side-cutter:
   4. 
   5. Now, you can place the harness in the base. The part with the fabric around it is the front :)
   6. 
   7. The clips should be a tight fit in the base. If neccessary, you can apply a small amount of glue on the harness clips. I would recommend hot-glue (not super glue). This way, the harness can be removed again for a better stand of the hat (in the end it will only be worn for a few minutes at the defense ceremony)