Beveling G10 and carbon and plywood fins - what do you want to know?

rfjustin

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I was thinking about 1/8" FG fins the same way, and how do you not end up with a sharp knife edge after beveling?
Is this all worth the extra 10 feet in altitude you would gain?:questions:
I bevel primary for aesthetics/cool factor, but you do gain some performance.

I avoid a knife edge bevel by taking progressive cuts, and taking my time.

I have done knife edge bevels before, primarily if the fins were going to receive carbon or glass fin to fin after. Adding composite layers over a knife edge bevel "softens" the edge quite a bit.
 

Dave A

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I bevel primary for aesthetics/cool factor, but you do gain some performance.

I avoid a knife edge bevel by taking progressive cuts, and taking my time.

I have done knife edge bevels before, primarily if the fins were going to receive carbon or glass fin to fin after. Adding composite layers over a knife edge bevel "softens" the edge quite a bit.

That's some fine beveling👍
 

rfjustin

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Thanks for sharing your thoughts & experience. Forgive me please, I haven't seen your work up close (or anyone's with that kind of bit) -- how deep are those groves in the bevels? Are they really shallow & easy to clean up? It's tough to tell from the photos.

Thanks!
Very easy to clean up, I hit it with a bar sander at the same angle, within a few passes, its good to go.
 

FlyBy01

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Yes, please bits and speed discussion.

I use the Dremel Router with a 'cone' bit to bevel fins. Must go slow and only take off a little at a time but do end up with uniform bevels. Set speed to just under mid setting.
care to post a picture of your setup?
 

Cherrywaves89

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Guys, setting the bit is not that hard. I like to set the bit so it will take a light cut. Run the fin through on one side, then flip it over and run it on the other side. Look at how thick the leading edge is. It will be way too thick. Move the fence back a smidge on one side and repeat. You will
cut off more the next pass. Keep going until you get the profile you are after. I don’t take my fins to a knife point as they are too fragile. I like to leave a good 1/16” on thin fins, more on thicker fins. It’s really personal preference.

Once you have the profile you like, repeat for all the fins. I do like to run all my fins at each setting as the lighter cut you take, the less tear out.

Some pics of my set up which is home brewed but has served me well. Keep your fingers back and use some scrap stock to keep your fingers away from the bit.

View attachment 508193
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May I ask why you guys have even built a jig in the first place? Why not just run your fins across the fence as it is? What’s wrong with this. . .?
 

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May I ask why you guys have even built a jig in the first place? Why not just run your fins across the fence as it is? What’s wrong with this. . .?
This method would tend to take a larger cut when it goes wrong. With the fence completely over the cutter only the outer edge is exposed. If it grabs at all it pushes the fin away taking a smaller cut which can be fixed with a second pass at the same setting. This is also friendlier to smaller objects.
 

rfjustin

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May I ask why you guys have even built a jig in the first place? Why not just run your fins across the fence as it is? What’s wrong with this. . .?
For my Ryobi tables, I found that plastic insert was not flush enough with the top of the table, and the G10 would "snag" a bit. Likely a limitation of the router table/set-up I chose many moons ago. Since I was able to make mine work to suite my needs/preferences, I have not been inclined to fix what isn't broken. Good question for sure...
 
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For my Ryobi tables, I found that plastic insert was not flush enough with the top of the table, and the G10 would "snag" a bit. Likely a limitation of the router table/set-up I chose many moons ago. Since I was able to make mine work to suite my needs/preferences, I have not been inclined to fix what isn't broken. Good question for sure...
The plastic inserts are a liability when you're routing anything small. The extra rigidity an aluminium insert gives is massive. That said not all plastic inserts are equal. Some are not as bad as others....
 

Buckeye

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May I ask why you guys have even built a jig in the first place? Why not just run your fins across the fence as it is? What’s wrong with this. . .?

1. The router bit should be buried in the fence for safety. Your method (which I did at first until somebody corrected me) will grab the fin and launch it from the table like a baseball pitching machine.

2. Your fingers are close to the bit. Too close for me. I use a push block.

3. The plastic inserts are too big and not flush with the table. I made a better insert from a piece of 3/32" fiberglass.

Pics here:

 

Zbench

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May I ask why you guys have even built a jig in the first place? Why not just run your fins across the fence as it is? What’s wrong with this. . .?
I didn’t build a jig to do rocket fins. I do use my router table for rocket fins when the need arises. As other state below, placing the work between the fence and the bit is not safe and hard to control. There is no way you can press the fin completely up against the fence like you can when the bit is buried in the fence and you press against it directly.
 

Cherrywaves89

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1. The router bit should be buried in the fence for safety. Your method (which I did at first until somebody corrected me) will grab the fin and launch it from the table like a baseball pitching machine.

2. Your fingers are close to the bit. Too close for me. I use a push block.

3. The plastic inserts are too big and not flush with the table. I made a better insert from a piece of 3/32" fiberglass.

Pics here:

Awesome. I actually went ahead and did a few dry runs with the router off yesterday because I suspected it was probably unsafe, and in the process, I too found that the insert was not flush enough. I built the jig, and voila. The fins are now perfectly beveled with a little meat left on the top for rigidity.
 

Buckeye

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Awesome. I actually went ahead and did a few dry runs with the router off yesterday because I suspected it was probably unsafe, and in the process, I too found that the insert was not flush enough. I built the jig, and voila. The fins are now perfectly beveled with a little meat left on the top for rigidity.

What is the jig of which you speak? I looked at all the posts in this thread and I don't see it.
 
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