What is it?

A modular fin system for slide-lock style SUP fins. 

Will it work with my SUP?

This was designed for my particular model year of Body Glove Performer 11. If the slot on your paddleboard is wide than ~20mm it will likely fit - but you can just print the Slide Lock and test it alone if you're unsure.

If you want this adapted to a particular fin mount type, feel free to comment below. I'd be happy give other mounting styles a shot if there is enough interest.

How is it assembled?

The Parts

1. Fin: The fin itself. There are 3 types included, more on this below.
2. Slide Lock: The base of the fin that slides into the paddleboard.
3. Clip: The clip that holds the fin, the slide lock, and the paddleboard together.
4. [Not printable]: Twine or rope for securing Clip to Fin
5. [Optional]: M2.5 x 20mm bolts can be screwed through the Slide Lock and into the Fin for added strength

Assembly

1. Remove all support structures, including the supports under the clip.

2. Align the 3 cleats on the fin with the 3 holes in the the Slide Lock. Press the fin down into the Slide lock firmly.

3. Slide the fin backwards. This should be slightly difficult, its intended to be a tight fit. 

4. Try pushing the clip through the hole. If it goes straight through without locking, you might not have seated the fin correctly in step 1. Remove the clip after testing.

5. Use a piece of twine or rope to connect the clip to the two holes in the side of the fin.

6. Slide the fin into the paddleboard and lock it in place with the clip.

What's the difference between the fins?

I will admit I am no expert in this field. The designs are based on some rules of thumb I found regarding manueverability, tracking, and stability. I'm sure there is room for improvement. The fin shape can be easily changed so let me know if your ideas in the comments below and I'll consider trying them out!

Tracking Fin

• Better at going in a straight line (tracking)
• More stable, less board wobble

Touring Fin

• Turns more easily
• Decent stability

River Fin

• Ideal for shallow areas, but at the cost of tracking & stability

Update: See A1_Tracking_Fin and A1_Touring_Fin stl's for Bambu A1-compatible variants

Print Settings

Originally I just printed these with 100% infill and water ingress wasn't an issue, but I wanted to try conserving filament so I've been experimenting with other settings. The settings below are the best I've found for watertightness, but please let me know in the comments if you have had better luck with different settings. 

• Material: PETG or another UV & Heat resistant filament
• Speed: Keep it slow to ensure proper bonding for waterproofing. I use 40mm/s for the outer wall, 150mm/s top surface, defaults for the rest.
• Layer height 0.16mm (this will help with waterproofing)
• Infill: 30% . Use 100% if you want it to be completely water tight.  
• Wall Loops: 5
• Top shell layers: 6
• Bottom shell layers: 6
• Support: Tree (auto), 30% threshold angle

Be sure to remove the support from the bottom of the clip before using it, otherwise you won't be able to get it out after locking the fin in place.