Tail wings bolt pattern - compatibility

[clay]

The intention of this thread is to find out what the tail wing bolt pattern is of the different brands.  And encourage a standard sizing so that all tail wings (stabilizers) are interchangeable and will fit any foil regardless of brand or design.


So I am stoked to learn that my F4 tail wings fit the Takuma Kujira fuselage.  I read on another thread that Signature and Unifoil also have the same bolt pattern.   I have four F4 tails and they have many more so this feels exciting to me, or at the vary least I'm not bummed that I need to spend hundreds more to get the feel I want.

I measured with a digital caliper measuring the space between bolts holes on the Fuselage (the inside or smallest measurement).

F4 and Takuma both measure 25mm.

Axis red fuselage measures 30mm.  Any other brands measure 30mm?

What is gofoil?

How about F-one?

Armstrong?

Attached photos are showing how I measured.

[bigmtn]

I'd recommend sending @kdmaui a message on instagram.  He's making tails for most brands now and could easily tell you what's compatible and not.

[DavidJohn]

Just wondering how you are measuring the hole spacing?

Are you measuring hole center to hole center?

My Naish foils are 35 mm.. and I thought Axis were the same?

[clay]

Measuring center to center seems to difficult, without special tools, or measuring inner and outer edges and then doing math...

So I'm measuring inner edges of the fuse bolt holes because thats easy with any caliper.

[jondrums]

can we please use center to center spacing?  the way you show is totally non-standard and confusing to me at least.  I understand you have a hard time measuring center to center, but instead you can measure what you've done and then add the hole diameter to get center to center

[clay]

can we please use center to center spacing?  the way you show is totally non-standard and confusing to me at least.  I understand you have a hard time measuring center to center, but instead you can measure what you've done and then add the hole diameter to get center to center

I have no horse in the way we measure, I just want to know what tail wings are compatible.

Hole diameter seems to be off, as in the "diameter" of Axis/Naish seems to have lost 1mm.  For example my measurement of 30mm plus + 6mm equals 36mm, when they are calling it 35mm. A 2X4 isn't, frustratingly confusing.

My plan was to update any posted measurement with a listing of compatible wings, and not confuse people with the measurements.

[Wingfoil1]

Cloud 9 is 45mm centre to centre

[jondrums]

Hole diameter seems to be off, as in the "diameter" of Axis/Naish seems to have lost 1mm.  For example my measurement of 30mm plus + 6mm equals 36mm, when they are calling it 35mm.

I'm willing to bet that if you measure the diameter of the hole in the fuse, it'll be 5mm.  you probably measured the hole in the wing.  Can't mix the math.  Either measure the minimum spacing AND the diameter on the wing or make the same two measurements on the fuse.

PS GoFoil is 30mm

[Califoilia]

Hole diameter seems to be off, as in the "diameter" of Axis/Naish seems to have lost 1mm.  For example my measurement of 30mm plus + 6mm equals 36mm, when they are calling it 35mm. A 2X4 isn't, frustratingly confusing.

Axis tail screws are M6 (6mm), so 1/2 or the middle of that would be 3mm. When added to your 30mm measurement of the two closest hole threads...would give you 33mm center to center...theoretically.

[PonoBill]

This is one of those kind of issues that created all kinds of nonsense at the beginning of the first industrial revolution that we are still living with today. SAE, BSF, Whitworth, BSP, BSCoarse, BSCopper, Metric, Metric JIS, etc, etc. Not just where to measure a hole, but what the size should be based on--major diameter, minor diameter, and even size of the bolt heads. A 1/4" Whitworth wrench is the same size as a 5/16BSF (both standards were invented by the same guy, if he were alive today I'd poke him in the nose) and it's a little bigger than 1/2" SAE and about 13.3mm. As a mechanic who works on vintage machines, it's enough to make you tear your hair out.

For the purpose of this project, if the measurements are off by .5mm the screw will cock and likely will crossthread and eventually rip the fragile aluminum threads out.

Let's not go there. The standard for blueprints is the hole center which is just the (outer measurement - inner measurement)/2 plus the inner measurement. Note math precedence. Subtract the inner from the outer, divide by 2 then add the inner. Your calipers will get you close enough, just use the pointy side for the outer measurement.

If you want to make the measurements a little more accurate and easier to repeat, put the screws in deep enough to make them not wobble and measure them using the flats of the calipers, not the beveled edges--inside and outside. Same process, but you'll be measuring the major diameter. Most calipers have a relief inside of the measuring surface--be careful not to use that--it's uncalibrated.

Incidentally, if you really want to use a wing with a spacing of (for example) 30mm on a fuse that's 35 you can easily modify the wing so it fits both. The cleanest way is with a drill press. You'll need an accurate pilot hole to add a second hole at either the front or back hole, depending on where the tail lines up best. I pick the hole with the most meat in the fuselage, which is generally the front, but you also need to match up to any fuselage contour. You need a pilot hole because the hole will probably be on the edge of the countersink and a larger drill will probably slip towards the existing hole. then I use a combination drill/countersink to make the final hole size plus countersink. All very easy with a drill press, feasible with a hand drill if you're careful and steady.

The axis fuselage has a swoop that dictates where the stabilizer will be, so you need to leave whichever hole lines the wing up properly and drill the other. I was recently tempted to modify my Takuma efoil stabilizer to try it on my axis. Unfortunately, the curves don't match and the Takuma stabilizer mounts on the bottom of the fuselage (same as the wing) while the Axis stab mounts on top. After contemplating all the fiddling I'd have to do to make this work and the fact that I have only hand tools here in SoCal I chickened out.

[clay]

Thanks for the responses.

A recap so far is that the following fuse/tails have the same (center to center 30mm) hole spacing:
F4, Takuma, Signature, Unifoil, GoFoil.

And that Axis and Naish have the same bolt spacing (center to center of 35mm).

Also Cloud9 is wider at (center to center of 45mm).

Can anyone measure their Armstrong or F-one?


I am guessing that whatever measurement the center to center spacing is, it is most likely _0 or _5 as in 30 or 35 ect...


Hey Bill do you know if anyone makes a jig or drilling doohickey for making another hole or expanding an existing one? 
I tried this eyeballing with a drill press and my hole was slight off center, meaning the tail wing mounted yawed to one side.

[PonoBill]

It wouldn't be too hard to make, but no, I don't know of anything directly applicable. You could probably adapt a Kreg shelf pin jig for this. I use mine for everything but drilling shelf pins.

[Piros]

All these brands the tail wings screw straight onto each others fuse . Uni , Sig , Takuma , GF , NSP & F4 . You can also take these rear wings and rerto fit the Cloud and NP . Simply mark the new holes in between the existing M8 holes drill and re tap M6 . The tail end of the Cloud is solid brass, 5 min job and you have the best of both worlds. Can't do it to the Axis and Armstrong due to the pedestal mount on the rear wing. Re shifting holes intsead of re tapping the fuse , I just fill the wing hole with "Knead it" and carefully re drill by hand.

I love nothing more than chopping up and playing around with my rear wings BUT I just got my custom 13.5" for my Takuma Kujira from Kane de Wilde "kdmaui" just blew me away & by far the biggest improvement to just changing one thing I have ever experienced. It has completely changed the way I ride just amazing and he can do them for any brand. Definitely worth looking into. 

[exiled]

I believe Armstrong is 33mm apart. MFC is 30mm too I think.

[clay]

Thanks for the posts!  Heard back from Kane -

These brands have the same bolt pattern (30mm center to center):
Unifoil, SPG, gofoil, F-one, takuma, F4, mfc, nsp.

These have the same (35mm center to center):
Axis, NP, and Naish.

Cloud9 is 45mm.

Moses is like 28mm?