Fin Boxes with futures

Hey Everyone,

I’ve got a gaggle of boards now and they are looking SICK! 

However. I have run into a problem that I don’t think is necessarily a problem 

I am using a home made jig for futures fins. The fin box is 5 inches long. My shapers square only has markings for a 4.5 inch and 4 inch base. So if I want to toe in my fins 1/4" can I just select a marking that is slightly less than that to acount for the fact with my longer fin boxes the toe in will be slightly larger?

What I did instead was much harder. I basically drew a line perpindicular to the stringer extending to rails. Marked the bottom of the fin boxes that I wanted with a dot. Then I draw a right angle line upwards from this point, measured out 5 inches and measured my toe in from that line. 

However, I am having some trouble making sure the angle is exactly the same on both sides.

Do you guys have any tricks? 

Thanks,

Adam

Use the back edge of a Futures fin for your frame of reference, not the outside edge at the rear of the box flange.  Most fin bases are 4" or 4.5" base length.  You can set and toe fins from the rail at trailing edge and lead edge.  It is very easy though(and more common) to set placement and cant by determining and using the center of the blank.  For instance a common Thruster might have a 3" or 3.5" to the rear edge of the center fin.  With that starting point marked with a pencil dot,   From that mark’ measure a fin base(4" or4 1/2") forward and make another dot.  By doing this you have established front and back of your center fin.    From the lead or front edge of the fin box go another full fin base (4" or 4 1/2") and make another mark at center.  Using your Shapers Square, center it on that mark.  Then come out to the rail and make another dot 1 1/2" or so off the rail on both sides.  This dot on each rail establishes the rear inside edge of the side fins.  Using your Shapers Square again measure 4 or 4 1/2" forward of the last dot on the stringer.  Got to rail and make a dot at where the lead edge of your side fin would be.  Only this time make the dot 1/4"closer to the stringer.  This will give you 1/4" toe.

I understand the concept but the application hasnt been perfect.

I measured my futures fin box length but it measured exactly 5 inches. Is the length actually determines by the channel? I think that would make sense. 

If that is the case and they are 4.5 inches my shapers square has spots for marking toe in which should hypothetically work. 

I tried to do it with a grid on the test board and here is what it looked like 


I thought I told you to not use the overall length of the box.  Use the length of the slot and the inside edge of the the slot.  I guess my telling you to not use the back edge of the flange got lost in my explanation.  I made reference to 4" and 4.5", but never referenced five inches nor the overall length of the box.  The overall length of the box(5") has nothing to do with it.

Haha yeah I didnt know what a flange was. But I still understood your meaning so I went and measured just the slit and it was bang on 4.5 inches so I used all of your other advice.

Got the other fins in with no problems but I think I’ll invest in the futures kit when it’s available because my jig isnt very user friendly.

 

When you get the jig look it over carefully.  You will see on the clear plastic insert used for aligning the jig a mark for Right rail and Left rail.  Use the appropriate mark for offset fins.  Center is the center line.  

Using my ghetto jig I managed to very tediously get the boxes in properly. 

Thanks for all of your help. I have learned that paying 200 bucks for a jig is probably worth it in the end especially if you are doing 20 fins…

 

Are you guys all using the official jig kit for FCS II and futures for example. Or have you guys also been forced into the home-made jig game? 

Now on to glassing. I am optimistic this will be easier given that I have at least used epoxy in repairs. How much different can it be?