Surfboard fins

Has anyone used the x-carve to cut surfboard fins?

I’m looking for a CNC that would be able to do this.


I have not seen that yet, but there should be no reason why you should not be able to do it.

There is the thread below where the X-CARVE is being used to make molds for carbon fiber hydrofoil wings.

Hydrofoil project

Do you plan to carve the fins out directly or make molds to make fins? Either one is definitely doable …


Brandon Parker

The Xcarve wil do that fine.
Easel (free CAD/CAM/Gcode sender all-in-one) however wont allow you to design curved shapes, but will happily carve it (send gcode) generated in other software like Fusion360 (which also is free for start-ups/students)

At what kind of scale do you want to carve surfboard fins? Personal use or larger scale?

Are you planning on simply carving them out of G10? Someone provided a link to my hydrofoil projects. I have found that the connection between the base of the mast and the fuselage has to be really hard and strong, so I have made that out of G10. You have to carve one side, flip the work piece over very precisely, then carve the other side with a mirror image file.

I am using Google Sketchup to design the foils, and its not that hard. Its getting the precise alignment that’s difficult.

I’ll post images of some of my results when I get home. I am willing to share my experience.

Someone else was looking into using an X-Carve for hydrofoils, but found it just couldn’t handle G10 in that size. Surfboard fins are much smaller, so should work fine. I would suggest the smallest size machine. If your fins are going to be smaller than 11.5 inches, I might even suggest the Carvey instead.

I’ve made a few surfboard fins on my fairly stock Shapeoko 2, so I suspect it wouldn’t be a problem with an x-carve. Fins for a longboard are fairly large, and although I made a few, one I designed was too big to be made on the Shapeoko (I’m about to upgrade my machine, and then it will be able to make larger fins). Most of my fins were made of wood, but some of layered fiberglass, and the first ones were plywood. I used Fusion360 to design the fins, and for center fins had a process whereby I’d flip the fin over to do the other side. I made several passes and went slowly, and the final result was very good. It took a very long time to carve each fin (but with my upgrade it should go faster), but the results were great.

I spent a lot of time thinking about how I wanted to do the halo, and the process I ended up with is a bit different from the way most people do it. It is more complicated, but I think the results were worth it. You can read about it here:

That page also has several pictures of the fin and my Shapeoko, as well as a picture of the finished fin.

Once I made some fins out of layered fiberglass, and you can read about it here:

That page also has a photo of the finished fins. It was MUCH easier and quicker to make the fins out of fiberglass, but I didn’t like making the layered fiberglass panels.

I am really bad at CAD and the hardest part of the whole process for me was figuring out how to do what I wanted to do in Fusion360 (mostly because of my halo process). But it was a very good learning experience.

Making surfboard fins on a CNC is a lot of fun, and I made some for friends. But I certainly wouldn’t do it as a money-making venture.

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Yes, I’m using G10 panels. What kind of bits work best?

I use Sketchup for Architecture, mostly straight lines, but haven’t attempted complex curved surfaces before. May have to watch some tutorials…

I haven’t used G10, but I made all my cuts with a 1/8" ball end bit. I tried some other shapes, but the ball end worked best. At present, my Shapeoko only has a 1/8" collet, so I was pretty limited in what I could do. Soon I will upgrade and be able to use 1/4" or 1/2" bits, and that would make things go a lot faster.

I think G10 will work well; I was thinking about making some fins from it, and hope to do so some day.

I designed my fins in FinFoil; I highly recommend it. I wouldn’t have known where to start if I was designing from scratch. Although I finished up with Fusion360, that was mostly for CAM, and all the real work was done by FinFoil.

Thanks for the info and links to Swaylocks, I haven’t been on that site in a long time. Halo looks great!

I’ve been playing around with Finfoil program, having touble getting Meshcam to make toolpaths though. I’ll check out Fusion360 too.

I use a 1/4 inch bit. Because a hydrofoil or fin doesn’t have much detail, a larger bit allows for a larger stepover, which saves a lot of time.

I make foil shapes by importing an image file from an airfoil database web page.

Import the .gif file into Sketchup, trace the outline, then use the Push/Pull function to make a 3D shape. You can resize the end of the shape you just made, then Push/Pull again, and repeat till you have your fin completed.

Using a 1/4" bit is definitely the way to go! That’s why I’m upgrading.

Kevin, if you do decide to use Fusion360, let me know and I could send you a Fusion360 project file; it would have the design as well as the CAM settings I used. It’s actually pretty easy, but the first time you do it, it can seem intimidating. I’ve had no trouble at all with the gcode Fusion360 generates.

Just ran across this post on surfboard fins and thought I would share a photo of one of mine. I’ve made dozens of fins of all shapes and sizes. Depending on what they want. Used to make base of solid layered fiberglass, but if you hit it hard enough, you would crack or break the front off at the hold down screw hole. I now use G10 material exclusively for the base section. This stuff is unbelievably strong! Never had a break since.

Cut on CNC at 60 ipm, with 1/8 downcut bit and .05 doc. I also extended the wood below the surface which increased the horizontal strength considerably. The fins are glassed with 2 layers of 6oz glass on both sides and halo edges. Extremely strong and only .375" thick.

This fin is 9" and made from curly Koa and one or my favorite longboard fins designs.

Thanks, downloaded Fushion360 and am watching some tutorials.

Thanks for the info Jeff, and nice fin. I started putting G10 in the base of my fins awhile back, stuff is great.

That fin looks great!

How did you connect the wood to the G10 base? Is it just epoxied and held together by the fiberglass, or is there some sort of tongue and groove, or something else?

The weak spot in my wooden fins was always the base. For most of my fins I would glass the wooden part with a layer of 4oz, then put this into a mold, and then fill the gaps with chopped up glass and resin, and when that was dry, put another layer of 4oz glass over it. There was a definite weak spot up where the screw goes through. I was trying to keep the finished thickness to about .3".

And then did you just sand the fiberglass and make the halos by hand? (that would be a lot quicker and easier than the way I did it, having the machine create the halo).

As I understand, you molded the base with chopped glass and resin? Chopped glass is very weak with very little structural strength compared to cloth fiberglass. If you still want to use glass for base, I would make a panel of multiple layers of cloth ( 6oz) to end up with aprox. .25" thickness. This may take 15 layers to achieve. I used to use 2 plates of window glass and sandwich the layup materials between them. Cut rough shape of your base (with base cutout to extend into base and glue together. Something like my G10 base. Hand shape fin and base. Glass 2 layers on both sides. With only one layer connecting fin to base, you will snap fin at base on a hard turn.
Extending the fin below the surface has greatly strengthened the fins. I have yet to have one break at the base, or anywhere else for that matter.

Halos are made by cutting cloth bigger than fin, and with each layer overlapping edge. When all dry, then I shape final edge to halo thickness. If I want a very wide halo, I would use fiberglass rope to forn halo.

Here are a couple of my earlier fins, before G10 and extension below surface. These were solid glass (cloth layers) bases. With the use of G10, I now never have a problem with the screw holes breaking.

Good luck and have fun making your fins…Jeff

PS: Yes, the holes are filled with resin…lol

Hey Richard, did you have any trouble with your FinFoil design when you opened it in Fusion360? I exported my fin as an STL file and opened in Fushion360, but the size is tiny, only 0.01" in length…

Am I missing something?



I sometimes had this problem, and if I remember correctly, it was caused by using the wrong units. I think you need to have your Fusion360 project in mm (you have the option). Once you do that, it should be close. I did use the measure function to check that everything is right; if not, it is easy enough to make it larger or smaller. I eventually figured this out, but can’t right now remember exactly what I did.
If you send me your email address, I’ll send you a sample Fusion360 project file (but maybe you don’t need it).

Thanks for the detailed info; I really like the fin with the holes. With my fins, they actually had 2 layers of glass go from the wood into the base: first I glassed the wood, and inserted that into the mold. I then added chopped up fiberglass and resin to make the base. Then I put another layer of glass over all of that. Luckily I’ve never had one break, but I am confident this is not as strong as what you’re doing, since as you say, the weak spot is the tab where the screw goes through. Here are a couple of photos:


Thanks Richard, still having some trouble with this. If you don’t mind it could help to see your file; my email address is

Hello, Im am fresh behind the ears but I love to surf. We recently moved to a new area and have much smaller waves can I make these on Easel. Fusion 360 do I need to use this program and if so whats the price and come anyone send me the file?

You could google “surfboard fin template” and pick one and import it into easel and make changes as necessary.