3D Printing 3D Printed leading edge

[MikeyDSlagle]

Has anyone ever done 3D printed bevels on fins before? When I was building my Mega Magg my fin beveling jig slipped, after all was said and done I ending up losing about 5/8" from the leading edge. It is slightly less stable without the extra surface area but not overly so. I had previously thought about gluing some half-round moulding to the fins.
Having never done that, and now being the proud owner of an Ender 3, I am looking at maybe printing me some rounded/beveled leading edges.
This will be for a Mega Magg and she isn't even going transonic, much less supersonic.

One problem I may have would be adhesion. My thoughts are to rough up the mating surfaces of course, then use epoxy and possibly screws or dowels. A jig for proper alignment will be easy enough to design.

And also, PETG or PLA? That is currently my only two options.
I have good days and bad days with PETG and it takes a bit to dial it in. PLA is easy peasy on my machine.

Would love to hear everyone's thoughts.

Michael

 

[dr wogz]

I would go with wood half-rounds. cheap & easy. No need to design anything, no need to print anything, And standard glues work

PLA can be hard to glue to, and can become soft in the sun or in a hot car.
PETG can be a pain to get dialed in right. (you might waste the whole roll getting your printer 'dialed in' to print it)
and plastics can be a pain to sand, fill, & paint..

 

[MikeyDSlagle]

I agree completely.
I currently have PETG loaded and dialed in fairly well. It's annoying. I can do a simple test print and it work great. Print the exact same thing immediately after, same code and all, and it not stick.

On something like this there shouldn't be a big issue with stringing, which I haven't had many issues with that so far, only because of simple prints I'm sure.

 

[Dugway]

I print PETG almost exclusively. I've printed both leading and trailing edges for a number of Cluster Ducks (six fins!), as well as skins for an Honest John and a Nike ASP. I haven't had any of them fail yet and it sure beats the heck out of trying to sand six fins to exactly the same profile!

 

[PedroTheRocketNerd]

I actually just saw a new product on Apogee, not what you are describing, but your idea reminded me of it. They are 3d printed angle jigs you put sandpaper in to sand a bevel into your fin.

 

[rocketlabdelta]

They are 3d printed angle jigs you put sandpaper in to sand a bevel into your fin.

NCR Airfoil Assistants, I presume:
https://northcoastrocketry.com/collections/accessories/products/airfoil-assistantshttps://www.apogeerockets.com/index.php?main_page=product_info&cPath=42_161&products_id=2689
I can't speak to 3D printed leading and trailing edges on thick fin stock, but @JohnCoker has glued 3D printed airfoil profiles to a solid core on projects like this one:
https://jcrocket.com/boosted-arcas.shtml

 

[PedroTheRocketNerd]

The Airfoil Assistants are what I was thinking of. I wonder if there is a free 3D-printable model out there for something like that.

 

[MikeyDSlagle]

I actually just saw a new product on Apogee, not what you are describing, but your idea reminded me of it. They are 3d printed angle jigs you put sandpaper in to sand a bevel into your fin.

The Airfoil Assistants are what I was thinking of. I wonder if there is a free 3D-printable model out there for something like that.

Something like that should be fairly easy to design. Fins in question are 3/8" ply, and I already lost some fin due to a jig slipping. They may be good for smaller builds.