Assembly of multi-part prints in 3D Printing - Mini Project: Build & Apply

Assembly of Multi-Part Prints

📖 Scenario: You have designed a complex object that is too large to print in one piece on your 3D printer. To solve this, you split the design into smaller parts that will be printed separately and then assembled together.This project will guide you through the basic steps of preparing, printing, and assembling multi-part 3D prints.

🎯 Goal: Build a clear understanding of how to organize and assemble multiple 3D printed parts into a final complete object.

📋 What You'll Learn

Create a list of part names representing the pieces to print

Add a configuration variable for the assembly order

Use a loop to simulate the printing process for each part

Add a final step to confirm the assembly is complete

💡 Why This Matters

🌍 Real World

Large or complex 3D models often need to be printed in parts and assembled later to fit the printer size and improve print quality.

💼 Career

Understanding multi-part assembly is important for 3D printing technicians, product designers, and engineers working with additive manufacturing.

1

Create the list of parts to print

Create a list called parts with these exact strings: 'base', 'arm', 'claw', 'cover'.

3D Printing

# Create the list of parts to print
# Your code here

Hint

Use square brackets to create a list and separate items with commas.

2

Define the assembly order

Create a list called assembly_order that contains the parts in the order they should be assembled: 'base', 'arm', 'claw', 'cover'.

3D Printing

parts = ['base', 'arm', 'claw', 'cover']
# Define the assembly order list
# Your code here

Hint

The assembly order list should have the same parts in the order they will be put together.

3

Simulate printing each part

Use a for loop with the variable part to go through each item in the parts list and simulate printing by adding a comment inside the loop: # Printing {part}.

3D Printing

parts = ['base', 'arm', 'claw', 'cover']
assembly_order = ['base', 'arm', 'claw', 'cover']
# Use a for loop to simulate printing each part
# Your code here

Hint

Use a for loop to go through each part and add a comment inside the loop to represent printing.

4

Confirm assembly completion

Add a final comment after the loop that says # Assembly of all parts is complete to indicate the project is finished.

3D Printing

parts = ['base', 'arm', 'claw', 'cover']
assembly_order = ['base', 'arm', 'claw', 'cover']
for part in parts:
    # Printing {part}
# Add a comment to confirm assembly completion
# Your code here

Hint

Simply add a comment after the loop to show the assembly is done.

Practice

1. Why do people print large 3D models in multiple parts instead of one piece?

easy

A. Because single-piece prints are always weaker

B. Because printing in one piece is always cheaper

C. Because multi-part prints use less material overall

D. Because printers have size limits and parts can be joined later

Solution

1. Step 1: Understand printer size limits

   Most 3D printers have a limited build volume, so large models cannot fit in one print.

2. Step 2: Recognize the benefit of multi-part printing

   Printing in parts allows assembling a large model that exceeds printer size, making it possible to create bigger objects.

3. Final Answer:

   Because printers have size limits and parts can be joined later -> Option D

4. Quick Check:

   Printer size limits = print in parts [OK]

Hint: Large models need splitting due to printer size limits [OK]

Common Mistakes:

• Thinking multi-part prints always save material
• Believing single-piece prints are always weaker
• Assuming multi-part prints are cheaper

2. Which of the following is the correct way to prepare parts for assembly after printing?

easy

A. Remove support material and smooth joining surfaces

B. Leave parts as-is without cleaning

C. Paint parts before removing supports

D. Heat parts until they melt slightly before joining

Solution

1. Step 1: Identify necessary post-processing

   Removing support material and smoothing joining surfaces ensures parts fit well and bond strongly.

2. Step 2: Avoid incorrect preparation methods

   Leaving supports or painting before cleaning can weaken the joint; melting parts risks damage.

3. Final Answer:

   Remove support material and smooth joining surfaces -> Option A

4. Quick Check:

   Clean and smooth parts before assembly [OK]

Hint: Clean and smooth parts before joining [OK]

Common Mistakes:

• Joining parts with supports still attached
• Painting before cleaning parts
• Using heat to melt parts without control

3. Consider you printed two parts with flat edges to be glued. Which factor most affects the strength of the joint?

medium

A. The surface area of the joining edges

B. The color of the filament used

C. The print speed of the parts

D. The brand of the 3D printer

Solution

1. Step 1: Understand what affects joint strength

   Joint strength depends on how well parts stick together, which relates to the contact surface area.

2. Step 2: Eliminate unrelated factors

   Color, print speed, and printer brand do not directly affect how strong the glued joint is.

3. Final Answer:

   The surface area of the joining edges -> Option A

4. Quick Check:

   More contact area = stronger joint [OK]

Hint: More surface contact means stronger glue bond [OK]

Common Mistakes:

• Thinking filament color affects strength
• Assuming print speed changes joint strength
• Believing printer brand impacts glue adhesion

4. You printed parts with interlocking joints but they do not fit together tightly. What is the most likely cause?

medium

A. The parts were printed with too high infill percentage

B. The parts shrank slightly after cooling causing tightness issues

C. The filament color caused the parts to expand

D. The printer layer height was too small

Solution

1. Step 1: Identify common printing issues affecting fit

   Plastic parts often shrink slightly after cooling, which can cause joints to become loose or tight.

2. Step 2: Rule out unrelated factors

   Infill percentage and layer height affect strength and detail but not usually fit tightness; filament color does not affect size.

3. Final Answer:

   The parts shrank slightly after cooling causing tightness issues -> Option B

4. Quick Check:

   Cooling shrinkage affects part fit [OK]

Hint: Shrinkage after cooling can loosen joints [OK]

Common Mistakes:

• Blaming infill for fit problems
• Assuming layer height affects joint tightness
• Thinking filament color changes part size

5. You want to print a multi-part model with different colors on each part and assemble them seamlessly. Which approach is best?

hard

A. Print the whole model in one color and paint later

B. Print parts in different colors but glue them without surface preparation

C. Print each part separately in desired colors and use precise joining methods

D. Print parts in one color and swap filament mid-print for color changes

Solution

1. Step 1: Understand multi-color printing limits

   Most printers print one color at a time; printing parts separately allows different colors easily.

2. Step 2: Recognize importance of joining quality

   Precise joining and surface preparation ensure a seamless final assembly without gaps or weak spots.

3. Step 3: Evaluate other options

   Painting later can be uneven; gluing without prep weakens joints; mid-print filament swaps are complex and less reliable.

4. Final Answer:

   Print each part separately in desired colors and use precise joining methods -> Option C

5. Quick Check:

   Separate color parts + good joining = seamless model [OK]

Hint: Print parts in colors separately, join carefully [OK]

Common Mistakes:

• Ignoring surface prep before gluing
• Relying on painting for color instead of printing
• Attempting complex filament swaps mid-print