Making a turn fin

Bob English said:

And now for the worst part of making the fins. Cleaning up the mess! Holly crap, a fly cutter has to be the messiest milling machine tool there is. That thing throws metal shavings ten feet in every direction. And I have to keep the mess cleaned up. The mill is in my garage. The last thing you want is to track metal shavings into the house and have your wife step on them barefoot! Not good.

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My wife complains about that all the time.

Thanks for the pictures of your process Bob. I never thought of using a fly cutter to mill them. I use an end mill on a tilt table. I old make what I need for my hulls. I like the way you both them down that’s a great idea. Thanks again!

Now I go to the big belt sander. Start with a 80 grit belt and even out the bottom of the fin. You see it in the first photo. Next you can see the sanded fin compared to the one still off the fly cutter. Now I put on a 320 grit belt and smooth out all the big scratch marks from the 80 grit belt. It also takes out a lot of the swirl marks from the fly cutter. It is a lot easier to sand the marks out than to try to remove them with the buffer. Now I go to the small (prop) belt sander and round off the front and back of the bottom of the fin. Next step will be the buffing wheel. That is the dirty job! I hope when I'm done with these fins guys will see just how much work goes into a good turn fin and understand why I sell them for what I do. It is a lot more than just " a piece of bent aluminum".

Just did the first polish on the fins. I bounce back and forth between the buffer and small belt sander with a 600 grit belt so I can clean up the leading edge and polish it at the same time. After the bend is put into them they will have another sanding on the 320 grit belt. Then be polished again. Then a final polish on a different buffer with a vented wheel and finer compound for that mirror finish. Taking a break right now. That big buffer dose give the back a work out. Plus I need to wash up. My face looks like a coal miner! Very close to being done.

I now go to the machine to put the roll into the bottom of the fin. Get the fin lined up perfect with the marks on the dies the put the roll in it. After it comes out of the roll machine you can see the marks the dies leave in it. That is why it is sanded again.

FINISHED! Now after three days of chipping away at the fins, they are done. You can see the difference in the finish and shine from the second buffing wheel with a finer grit compound. Now you have a RTR turn fin that looks like "eye candy" on your hydro. Even after making at least seven hundred of these over the years, it is still a long process making them all from scratch. But doing something like this dose give you a good feeling knowing, I made this!

Thanks Bob. Being a manufacture also, some people don't realize how much work & time goes into make our stuff to sell then they want a discount

Alan Elzer said:

Thanks Bob. Being a manufacture also, some people don't realize how much work & time goes into make our stuff to sell then they want a discount

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AMEM BROTHER and we do it because we all love playing with our toy race boats. My bucket list is full and most of them have to do with boating.
Mike

Bob English said:

This is something I have made for years. They are a fin and bracket for hydro's and Thunder boats. I have showed the process of making them on a different web site. I know some of the guys here go to that site and have seen them being made. But a lot of guys here have not. So is there any interest of seeing it done and the process explained?

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Hi Bob,
do you sell your fins on here or elsewhere

thanks

Shane

I sell them all the time. It is just on another web site. I sell the fins for $65.00. Or I sell the fin and bracket set with hardware for $87.00. The brackets are a lot of work for me to make. They are not just a rough cut piece of 6061 aluminum. First, when I started making the fins, I wanted the best supporting bracket I could have. If you look at these the bracket is 3" long. All the other ones I have seen sold are 2 1/2". The extra 1/2" dose make for better support. The reason you see 2 1/2" ones is because of the angle available. The side the goes up on the bulkhead is 1 1/2". You can find 2 1/2" X 1 1/2" angle. But try to find 3' X 1 1/2". You can't find it. I have to buy 3" X 2" and cut down the 2" side and machine a new bullnose on it. Just one more step to go through. And if you look at them every side is machined in the mill. They are not just a rough cut piece of angle. Also the side that goes up to the bulkhead is machined so the bracket is perfectly square. If you get a big piece of angle and put it up to a good machinist's square, you will see it is never perfectly square. Mine Are! Again another step I go through. I make the brackets so my fins work as good as they can. They take so much work that buy the time I buy the aluminum and hardware and all the time to do them, there is no money in it for me. It is just for my fins. I have not seen any other guys make fins and then offer a Very good bracket for them like I do.
So when I sell the fins I always advise guys to get the fin and bracket set.