Rounding or Knife Edging G12 Fins

[Mark Avrech]

Has anyone had any luck Rounding or Knife Edging G12 Fins using a router table and bit?? Is the G12 too brittle for this?

thanks
Mark

 

[dhbarr]

https://www.rocketryforum.com/index.php?posts/1888286

 

[rfjustin]

You can knife edge G10, no issues at all. The issue is, it will retain its sharpness and will cut. The only reason I have ever knife edged G10 or carbon plate was for minimum diameter builds that were going to receive carbon or glass tip to tip. This lamination process will "thicken" the edge and it will be rounded out a bit once the laminations are complete.

 

[pondman]

Has anyone had any luck Rounding or Knife Edging G12 Fins using a router table and bit?? Is the G12 too brittle for this?

thanks
Mark

Done rounding with a router, no table, with excellent results.

 

[rewilfert]

G10 or G12? I've only seen G10 sheet.

I've used a carbide round over bit in a router and the finish comes out nice and smooth.

 

[Mugs914]

Maybe Im a glutton for punishment, but Ive always just rounded G-10 fins with sandpaper.

I start with something like 120 grit and work my way down to finer grits. You can just about polish the things, though I usually leave 'em a little rough for paint adhesion purposes.

It actually goes pretty quick, though if you are trying to round a 1/2" thick G-10 fins I would grab a power tool of some sort.

Oh, and wear a mask regardless...

 

[kbRocket]

I like to do most of the work with a file. It keeps the cut flat. Sand paper rounds more.

 

[JohnCoker]

There are a couple of different techniques on this page:
jcrocket.com/finbevels.shtml

 

[Chris_H]

If you have a router table with a fence, one of these burrs is an excellent way to bevel fins. The fin is pushed between the fence and the bit. The fence is set so that the bevel almost meets the centter of the G10 thickness, leaving a micro flat on the edge. You could set it to razor, but you will be sanding these afterwards anyway, and you can choose your radius at that stage. This is safe, and does not have the same level of kickback danger as standard router bits. Proceed with caution as always, however. Safety glasses, respiratory protection, maybe a thick shop apron, etc.


There is also a shallowr bit, maybe 7 degrees? I do not recall exactly. I have not used it, yet.

CJ shared this technique, it is awesome. Quick to set up, easy. Problem solved.



https://www.mscdirect.com/browse/tn...MI5rj0hqeN6AIVWxitBh01oA70EAYYASABEgIgKvD_BwE

 

[kbRocket]

John's fin bevel page shows a great idea for using a sanding disk on a table saw.

Instead of making a fancy jig for the table saw, consider purchasing a jig. It can precisely set both tilt and offset from a table saw blade.
Here is the low cost version I own: https://www.grizzly.com/products/Grizzly-Tenoning-Jig/H7583. You can get it from Amazon and other places.

I haven't tried it yet, but I am now intrigued to buy a 10" sanding disk.

It might be possible to use the tenoning jig on a router table. You would need to check how far it is from the miter slot to the router bit to know.

 

[Rocketjunkie]

If spending some time supersonic, knife edge the fins. Otherwise, round them.