Hey all,
I built a 5’8" x 20 1/2 x diamond tail fish type of board and I’m having hard time wrapping my head around the fin placement. I tried my normal quad placement and the diamond cut outs really give the apperance that he fins a re too far back towards the tail… The cutouts are 1 inch from tip of the tail. Should I reset my measurements from cutouts and not the tail tip? Or split the difference? Idk… Or, if anyone just has better placement ideas please let me know.
Quad Setup
Front Side Fins: 11" From tip of diamond tail and 1 1/4" from Rail
Back Side Fins: 5" From tip of diamond tail and 1" from Rail
Lets see a pic. I have never heard of “cutouts” in reference to a diamond tail. Five inches doesn’t sound right. But I’m no expert on quads and would have to get out my notebook or take a look at a Quad I have shaped to say for sure.
5" up from the tip of the tail is right in the zone. some people would even go back a hair. Id go 10 7/8 on your sides and put those rears at like 4 7/8 or 5 up from the tip and 2" off the rail with your shapers dot. With quads its all about understanding the cluster and how moving the placement of those rears around can make a board feel so many different ways. The closer your rears are to the rail and the side fins the more they feel like twin. The farther off the rail or closer together theyre placed they feel more like a thruster. The closer you put them together vertically the more pivoty and the farther apart they feel more stiff/ tracky. But either way measure from the tip of your tail, the whole point with diamond tails is to shorten the rail line.
. PS—- 4 1/2” and 11 1/2” FSC Thruster trailing edge. Grouped tighter, with a single tab trailer gives you some adjustment. Get rid of the single tab rail fins add a two tab rear and you’re a Thruster. Yes you can fin all day long and by doing so you will learn the basics of where The average shaper marks his fins. But the shaper who experiments, designs or has something different in mind, is not the average shaper.
No I didn’t break out the tape or my notebook. Didn’t have time today for a tutorial. Manana perhaps. PS— 5” and 13” to the tips of the swallow from the back of a standard FCS Thruster fin.
Fins placement and shape could be a subject of controversy. I never be at ease with it. I measured placement on many boards, read here and there, listen to old time experienced shaper and find my “happy medium” and stay conservative with it. I do same with board shape. Never too disapointed.
The categorization of “blind” is relative.
Depends on your frame of reference.
For the most part, the tone and content at Sways has become civil, useful and tolerant — creating a solid DIY forum.
The quality information available to those willing to search old threads is extensive.
Mike has also made additional useful resources available to those who might be interested.
There are more than a few active, knowledgeable members who contribute to that data base (with tolerance) from a variety of frames of reference…
If I get a chance tomorrow, I’ll check the measurements on the boards I posted pics of. Pics of a board from the tail always look exaggerated. My bet is that the rear fins to the trailing edge are somewhere very close to five inches. I was also looking at a CI Flyer that I am working on. The “dot” is at the trailing edge of a stock FCS fin. Not at the rear of the box slot.
Thats correct, when your using a standard thruster or quad set where the fins base is 4.5” the rear of the fin will be the dot with both fcs and futures. When I answered that guys question he was specifically asking about Twin Keels in Futures boxes where depending on the fin it can hang Way past the box. That’s where you need to account for the overhang because you always mark for the fin tab route. That’s what he was asking. I was a finner, sander and shaper in a production shop and routed fins for numerous labels. If I don’t know the answer I won’t be posting
Completely understood. I never shape anything that would require keels. Rarely shape Twins or Fish. There’s another shaper 20 miles up 101 that does a nice job on both and buys all of his materials from me. I send ‘em to him.
