Intent: 

A small wire reel that can be installed/removed and used with both ends of the cable still plugged in. 

Design Goals and Features: 

• Install, adjust length, or remove without unplugging either end of a wire 
• No aggressive bending of cables (like flat reels can do) 
• The sharpest bend in the wire is static (no repeated flexing) 
• Low profile 
• Will extend with wire pull 
• Reels in wire twice as much per rotation than a normal reel 
• No reduction in useful wire length even when installed 

This Spec: 

The attached files have been optimized to work with a 6m iPhone cable. 

• Maximum 4mm wire diameter 
• Minimum 20mm wire bend radius 
• 20mm assembled thickness 
• 103mm assembled  outer diameter

Parameters: 

I tried to parameterize this design but fusion 360 kept having bugs so did not continue trying to do so. It is mostly working in terms of parameters so feel free to adjust parameters at your own risk and look for any required post adjustment corrections. 
 

Printing: 

These pieces should be printed separately (can be at the same time but not assembled). The orientation should have the inner piece with the split down the middle facing up and the outer piece with the flat face on the build plate. 

I recommend printing with organic supports. Any other print settings are up to you as they should not limit functionality. 

Thanks 

Let me know if you try it and have any issues. I have tried it (in a few different dimensions) without any issues. 

There are many upgrades that can be done to this design, I just stopped where I was happy enough, so please have a go at improvements!