Summary: The Owl Pellet Discovery Kit is a realistic, durable, reusable and multi-use owl pellet model for student dissection. It acts as a base for a larger project where students design additional bones and pieces. The 3-D models in this kit include a mouse skull, rib bone and a femur. Typical owl pellets can also contain beaks, talons and many different bones that are held together by undigested fur which is simulated by a dryer-lint formula in this project.
Print Settings: Printer Brand: MakerBot Printer: MakerBot Replicator 2 Rafts: Yes Supports: No
How I Designed This/Design Tips: Based on dissection of an owl pellet with real bones, I designed these models using 123D Design and 123D Catch. I recommend putting a base under any bones that are lopsided or unbalanced. If you have some portion that overhangs, add a support which you can later snip off after printing. Flipping a bone upside down for printing can also eliminate overhangs. If you use 123D Catch you need to take a sufficient number of photographs to create your model - Catch will prompt you if more photos are required to generate the mesh. 123D Design's capabilities allow you to add intricate parts to your design and manipulate them, but you can also work with basic shapes.
For the skull model included here, after completion of the design I inverted the piece to ensure printing would have a steady base. A raft was added for printing of the very thin, small rib bone and femur - the rafts easily snapped off after printing but gave a solid foundation during printing and until cool.
Overview & Background: Students will learn to dissect owl pellets and identify bones; advanced students or higher grade levels will also design a new replica piece, modeled upon a picture of a small rodent bone or bird skeleton, for inclusion in the dissection pellet.Dissection of a real Owl Pellet takes extreme care to reveal many fragile bones and non-digestible peices
Objectives: Students in 4th-8th grade will be expected to 3-D print the bones included here as well as creating one new bone/piece of their own (this can be done individually or in small groups). Students can use a photo of a bone to design a replica. They are expected to print their newly designed bone for inclusion in the pellet, thus the collection of bones available for future pellet dissections continues to increase and becomes varied. Students will then create an owl pellet (recipe provided) including the 3-D printed items and then through dissection identify the pieces they discover. If students are given random assortments of 3-D printed items each group or individual will have a unique set of pellet contents. Students in 2nd-4th grade can also complete this project with focus being on the dissection and identification process; teachers can prepare pellets ahead of time for this lesson. AudiencesGrades 4-8 are able to complete this entire project. For younger audiences it can be simplified and design of a new piece may be excluded or completed as a class. In more advanced Design, Biology or Anatomy classes the quantity or skill level of bone selection for design can be increased.
Subjects: Science Animal Studies Biology Design/CAD Skills Learned (Standards) Dissection/Fine Motor Coordination Identifying/Scientific Reasoning Following Instructions Deductive Reasoning/Making an Educated Guess 3-D Design - 123D Design, TinkerCAD or similar Creative Thinking Using a 3-D printer
Materials: Dissection probe, tweezers, magnifying glass, 3-D printer, CAD software, replica pellet bones, replica pellet ingredients (see References), skeleton charts or pictures for reference (see pdf Thing file).
Step-by-Step Overview: 3-D Print the 3 bone models provided in this project. Each student pellet or pellet dissection group should have a full set of these 3 models. Creation of a new or unique bone or non-digestible part of the student's choosing (grades 4-8) This can be done individually or in small groups depending on design skill level of students and accessibility of computers. 3-D Print student's newly designed bones, talons or beaks. Prepare Owl Pellet "recipe" (found under References). Assemble replica Owl Pellets using printed pieces and pellet recipe. Teacher could hand out random sets of 3-D printed bones (approx 4 per pellet) for each pellet or students could assemble pellets with the 3 provided here plus their own new creation. Allow for drying time of at least 48 hours, possibly 60-72 for pellets to be ready for dissection. Dissection of Pellet including Identification of contents. It is suggested that students be given pellets randomly so they do not know what bones they will discover and can then identify them from the charts provided. Examples of actual owl pellet bone and non-digestible parts for additional design insiprationDurationThis project could take 5 hours of classroom time and should be incorporated and interwoven with lecture and discussion within the Animal Studies or Biology curriculum :
1 hour Printing (for 3 bone models provided here) 2 hours Design (new pellet creations) 20-25 minutes to print new creation (per item) 30-45 minutes (preparation of multiple pellets) up to 1 hour Dissection. There is also a drying time for pellet mixture of 48-60 hours - leaving pellets to dry over a weekend would be ideal.