Fly Fishing Reel

To download the STL files and assembly instructions view the project on thingiverse: https://www.thingiverse.com/thing:4846834

Objective

A number of people have attempted to design 3D printed fly fishing reels. However, all of their designs share the same critical shortcoming: the drag system. The drag system is the most essential element of a fly reel. It is the mechanism that fishers rely on to fight the fish to the bank without breaking their line and losing the fish, particularly with larger fish. Having a shoddy fly reel therefore puts a fisher at risk of losing their best catches.

Other 3D printed fly reels rely on a “click and pawl” drag system. In this design, when the spool is counter-rotated in order to release line, a gear pushes a spring-loaded latch that applies some resistance or “drag.” This is a simple but outdated system that has a couple of major drawbacks. First and foremost, the drag is not adjustable. This means that regardless of if the fisher is catching a 6-pound fish with five-pound tippet or a one-pound fish with two-pound tippet, their fly reel will provide the same amount of drag. As a result, many of these 3D printed fly reels require the user to "palm" the reel, or create drag by pressing their palm against the spool of the reel. This is not the best solution.

My goal is to modernize 3D printed fly fishing reels by designing a reel that uses an adjustable disc-drag system. A disc drag uses a material that has high sliding friction (such as cork) to apply resistance between the spool and the frame of the reel. This type of drag is preferred by most fishers and is used in the majority of fly reels sold today. I also like this system because it is mechanically simple yet performs well.

On this page I will describe the process that went into designing and building the world's first ever 3D printed adjustable disc drag fly fishing reel.

The fly fishing reel that I designed.

Design Process

In order to reach the ultimate design I worked through many prototypes. Although my ultimate goal was to design a disc drag reel, when I started this project I did not know how to accomplish this. Therefore, I started by designing a “click and pawl” reel similar to the other 3D printed fly reels.

This reel did not work very well. Some components, especially the frame, were too flimsy. The click and pawl mechanism also did not work particularly well. Despite being poorly design, this prototype reel served as a good template that I improved upon for later versions.

My initial prototype which did not work very well.

A pile of prototypes between V1 and the current version.

I will discuss the prototyping that went into the various components of the fly reel In order to reach my current design. Subsection A) discusses the frame design, B) explains the drag mechanism, C) examines the spool design, D) covers the drag-set knob, and E) reviews the handle design.

A) Frame Design

The frame is the simplest yet most essential piece of the design. It holds all of the other sections of the reel together and connects the reel to the rod. Therefore, my primary concern in designing this piece is the strength. The first version was too flimsy which meant that the whole reel bent under pressure. In order to fix this problem I made the walls thicker and printed with higher infill.

I also fluted the spindle in order to reduce rotational friction of the spool around the spindle. An M5 bolt should be super-glued into the center hole of the frame. The drag-set knob tightens an M5 lock nut onto this bolt in order to adjust the drag.



Initial prototype of the frame.



Final version of the frame

with the M5 bolt installed.

B) Drag Mechanism

The most challenging part of the fly reel to design was the disc drag mechanism. Fly fishing reels apply drag in a single direction. Therefore, I needed to come up with a solution that would apply friction in one direction yet spin easily in the other. I tried several ideas to determine the best method.

My first idea was to use a one-way bearing as seen in this video. The unusual shape of this bearing means that it turns easily counter clockwise, but the points of rotation catch and do not turn clockwise.

This is a clever idea, but when I increased the drag, the downwards pressure prevented the bearing from spinning smoothly in the counterclockwise direction, so I moved on.

My next idea was to use a ratchet design. Cut pieces of zip tie (above in purple) allow the spool to spin freely counter clockwise and lock when rotated clockwise.

This design worked better than the one-way bearing, but I still had the problem that tightening the drag added too much pressure that prevented the plastic components from spinning smoothly, even when greased. However, this idea had potential.

I added ball bearings to the ratchet design and they worked perfectly.

Note that the drag mechanism now has ball bearings on one side to spin smoothly, and cork glued to the opposite side to add friction.

With the bearings in place the drag system spins smoothly in one direction.

In the opposite direction, the zip ties engage and the drag system applies smooth, even friction through the layer of cork.

C) Spool Design

The spool is the part of the fly fishing reel that holds the line. The spool is made of 3 components that are superglued together. The design remained largely the same from beginning to end, with only a couple of minor changes to help things to fit together perfectly.

I tried to get a little bit artistic with this part of the reel by adding some fun holes and patterns. These patterns are also functionally important because they help the line dry out after fishing.

D) Drag-set knob

This knob lets users tighten a lock nut by hand. This lock nut goes onto the M5 bolt inside of the frame and applies pressure through the spool, through the drag mechanism, and into cork. By adjusting this knob, the user can easily adjust the drag by changing how much friction the cork exerts.

E) Handle

The handle is a simple two-piece design. The inner piece (right) goes through the outside handle and is super-glued into the square hole in the spool. Then the handle spins freely around the inner piece.

Conclusion

Overall, I am extremely pleased with the performance of this fly fishing reel. This reel is strong, lightweight, and has a smooth, consistent drag. I am pleased that my 3D printed fly fishing reel has a comparable feel and performance to the $120 high-quality fly fishing reel that I normally use. The reel I designed costs about $10 to make ($5 for plastic and $5 for all of the other parts). The performance at that price is pretty remarkable.

I hope to continue improving this design, and I look forward to using this reel and hopefully catching some nice trout with it!

The reel that I designed side-by-side with my other reel.

Update: New Improvements

By fishing with this reel several times and asking all of my friends for feedback, I found 3 main things that needed to be improved:

  1. I added another bearing onto the top of the spool. This additional bearing makes the reel even smoother than before, and also makes it easier to adjust the drag-set knob.

  2. I improved the clearances of some parts so that everything fits together closer. This makes the reel a few millimeters slimmer.

  3. I accidentally dropped the reel and the handle broke, so I reinforced it with a screw. After several drops and many hours fishing this is the only component to break, but I will continue to reinforce the reel as is needed.

The additional bearing drastically improves the performance of the reel.

Improved clearances mean the reel looks cleaner and functions better.

This screw adds extra strength to the handle, and the rounded cap prevents the screw from catching on the line.

I am excited to continue to fish with and improve the design of this fishing reel!


Several people have asked about purchasing a reel. I will sell them for $50 each (including shipping). If you want to buy one please send me an email through the contact page.