fin alignment jigs.....

hey all, so ive hotcoated my first baord, lookin smooth, and went to do my plugs. of course i was arrogant enough to think i could do this without (in hindsight) proper research.

one of my rail fins came out great, but the other didnt so well. i used a sidebite fin and stablilized it in place (with tape)…

im sure you pros can imagine the results. well i have resigned myself to realizing i need an alignment jig (which i didnt know existed until searching the sways archives). does anyone have a link for specs where i can make one, or hell even buy one. ive googled the hell out of it and cant find anyplace selling fin jigs.

thanks AGAIN.

get some wood. cut it at the angle you want to set your fins.

yep… I have two identical blocks of wood, with different angles cut on each corner… 2, 4, and 6 degrees. That’s all I need, personally, but you could do half degree increments and keep sets of blocks on the self.

I set the angle with the blocks, and stablize them with plumbers putty. After I pour the resin, I double check using the blocks, and make any adjustments. Then I secure them with tape. A final check and you’re done.

ok, well i am a bit confused.

ive got my lines in (under the glass), by eye they look right where they should be. i take my whole saw and get that spacing right. now the fcs plugs have those two little tabs that stick out (somewhat) paralell to the stringer. those tabs i had resting on the board in line with my pencil line.

now im lost on what your two pieces of wood are doing. making a sandwhich with the fin in the middle with the bottom edge cut to your desired degree? and using putty to hold them there? then tape?

see, im thinkin of making a device that would have two tabs just like the fin tabs, then have a piece of wood perpendicular ot those tabs that would have set-screws through it touching the board. the angle could then be set by simply adjusting each screw. of course i think of this NOW.

and for my fin thats jammed up? should i whole-saw it outta there and start over?

All I do is have one block of wood for each fin. I put the plugs on the jig (or in your case, the fin), put the plugs in the holes, and put the block up against the inside of the jig (the flat side of the fin) to set the angle. Then I stabilize the jig (fin) with putty, and remove the block.

I’d definately drill out the bad plug and start over.

helpful as always my fellow jersey-ite.

and ur jig is just a piece of woood shaped like the bottom of a fin?

Here’s what I do and it works well. I set the angle with a carpenters locking bevel, (a cheap tool, see attachment ), with this you can very easily copy other peoples fin angles or set your own using a protactor.

To start with I align the fin jig on the marks drawn on the board and use a blob of putty at the front and back of it to keep it in this position. Fin jig here means the dummy or setting fin such as the one you get from fcs that the plugs are placed on. You don’t need to buy them though as they are a piece of piss to make out of MDF) At this point the fin jigs base can’t move back, forward or side to side but I find the angle is best held with tape.

I set the angle with the bevel and use tape to keep this angle set, by using both the tape and putty you know FOR SURE that the fin jig won’t move.

Check against an even background or a grid to make sure everything looks OK, adjust if the angles don’t look the same, you usually don’t need to adjust unless the tail bottom shape is a little out. I always use my eye as the final say, if it looks right, it is right in my book.

Hope thats of some help.

Hey surfer,

I wrote you this, first look at my very bad drawing.

  • The tangus of FIN CANT (â for Beta) = Length opposite side divided by length adjacent side (in inch). On condition there is one straight corner of 90 degrees in the triangle. Please do not ask why, I learned it in school, and it comes in handy.
  • Length opposite side = Tangus of Fin Cant (â)* Adjacent side
  • Adjacent side = 11,00 inch = length of paper, or somewhat.
  • Tangus of Fin Cant, 6,000 degrees = (use calculator, or Windows Scientific calculator) 0,1051042
  • â = O / A, so to get O, multiply both sides by A, giving âA = O, or O=â*A
  • Length opposite side = 11,00 inch * 0,1051042… = 1,1561466 inch = 1,156 for gods sake.
  • Go back to paper (or directly onto wood), and set out this width on bottom = length Opposite side = 1,156 inch. You now have your fintool almost ready
  • Get the wood, or whatever, out. Make sure that one side is SUPER straight.
  • Put paper on top of wood, make it stick, and copy the triangle onto the straight side. Understand?
  • Cut out your tool.
  • Cheap, pretty precise, fast
  • Then see what you like and change accordingly
  • hope U understand, if not i will help out further

Best to you!

Howzit sparks, We call that tool a sliding bevel square and it’s what I use to set the fin angles also. I also use a protractor to set the tool at any degree I want. They also work well for doing beveled rails to make sure the bevels are the same on both rails.Aloha,Kokua

surf3184,

An alignment jig to set the cant can be as simple as a piece of cardboard cut at the angle you want your cant to be…

All indications are you could benefit greatly from the FCS installation video.

It’s only $10 or so and will help loads - there was a thread about it a couple of days ago - any board material supply outfit will have it (Foam E-Z, Fiberglass Hawaii, et.al.).

Once you see it the light goes on and the install becomes a snap - then you get the install kit and it REALLY gets easy.

You should check it out and always pay attention to their recommended glassing schedule to avoid failure.

Shape on…

Pete

PS - Just found my VHS install vid. Could send it to you (need it back though) so you can get the full skinny.

   P.M. me with your address and I'll send it if you want to check it out...

i certainly appreciate the offer my man, but you would have to send me your VHS player too:) ill order it on DVD. im just the kinda guy that likes to do things my own way (the hard way) which usually creates lots of mistakes, but allows for innovations sometimes too.

im actually taking a break from making my own jig now. its kind of a cross shape with wholes for drilling the plugs at the right space and screws at the ends of the cross to be able to adjust for cant. ill post pics when im done.

Here is my jig, I started using it after much the same drama. I’ve also used the adjustable angle, but the plug still wanted to float up before the epoxy hardened. I set the jig against the board with childrens ‘playdoh’ bought at ikea. works fine.

regards,

Håvard

Your eyes…are your best tool.

A compass/protractor/sliding right-angle/cheaters ALL help…but you got to have the EYE !