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Stiffest wing to fuselage connection type

Posted: Sat Sep 12, 2020 7:57 pm
by dave1986
I own a Moses Onda (633) foil for kitesurfing. I'm looking to buy a bigger hydrofoil for wingsurfing. The obvious choice is the Moses 1100 wing (2100cm² area). However I'm aware that the Moses wing to fuselage connection (3 screws) is quite basic and not the stiffest compared with the likes of Axis (wing screwed to wide plate on fuselage) and other brands which use a tight fitting spigot connection (rod into hole).

What I really want to know is whether the "basic" wing-to-fuselage connection of Moses is significantly more flexible than other options? Or is the difference negligible?

Re: Stiffest wing to fuselage connection type

Posted: Sat Sep 12, 2020 8:27 pm
by tkaraszewski
I have nearly lost a Moses 1100 wing in the water because, I’mm my opinion, the connection for the wing is not really strong enough for a wing that big unless it’s carefully checked and looked after. I now check and re-tighten the bolts in my 1100 for each session, even though I don’t think that should be necessary.

Re: Stiffest wing to fuselage connection type

Posted: Sat Sep 12, 2020 8:40 pm
by tegirinenashi
Depends how often you switch the wings. If not that often, then glue the wing to the fuse before tightening the bolts. Plus having some glue in the bolt threads helps them getting loose slower. Be careful with glue selection, for example epoxy resin would connect the parts permanently, but something like E6000 or Aquaseal can still be disassembleable.

Re: Stiffest wing to fuselage connection type

Posted: Sat Sep 12, 2020 8:56 pm
by dave1986
I won't glue the wing to the fuselage, but I have no concern about the bolts coming loose or not being tight enough etc.... What I really want to know is whether the "basic" wing-to-fuselage connection of Moses (assuming all bolts are tightened correctly) is significantly more flexible than other options? Or is the difference negligible?

Re: Stiffest wing to fuselage connection type

Posted: Sat Sep 12, 2020 10:07 pm
by tomtom
Firstly Moses connection is just 2 screws - and quite tiny. But you really cannot have opinion on mast fuse connection just from look. All strength come from mortice tenon joint. This can be depending on execution stronger than much more robust looking connections. I have stiffest mast from moses and did not find fuse joint weak point even with 1100 wing. Moses kite 90 cm mast is very soft for your reference.

Re: Stiffest wing to fuselage connection type

Posted: Sat Sep 12, 2020 10:54 pm
by tkaraszewski
This is how I came in from the water with my 1100 one time. I could not ride it like this, I has to schlog in without foiling. The bolts loosened enough that torque on the rear one snapped it off, making the whole situation even worse.


Re: Stiffest wing to fuselage connection type

Posted: Sat Sep 12, 2020 10:57 pm
by dave1986
tomtom wrote:
Sat Sep 12, 2020 10:07 pm
Firstly Moses connection is just 2 screws - and quite tiny. But you really cannot have opinion on mast fuse connection just from look. All strength come from mortice tenon joint. This can be depending on execution stronger than much more robust looking connections. I have stiffest mast from moses and did not find fuse joint weak point even with 1100 wing. Moses kite 90 cm mast is very soft for your reference.
You are talking about the mast-to-fuselage connection.

My question relates to the wing-to-fuselage connection stiffness (assuming all bolts are tightened correctly)

Re: Stiffest wing to fuselage connection type

Posted: Sat Sep 12, 2020 11:22 pm
by nixmatters
If you want the stiffest possible front wing to fuselage connection, have some patience till Cabrinha release their 2021 foils. No plates, rods and complicated engineering :wink:
Their largest front wing will have less than 2100cm2, but should be big enough for winging.

Re: Stiffest wing to fuselage connection type

Posted: Sat Sep 12, 2020 11:25 pm
by tomtom
sorry, my fault

anyway there is zero problem with fuse to wing connection neither /on my side/ up to 1100 wing.

Re: Stiffest wing to fuselage connection type

Posted: Sun Sep 13, 2020 1:35 am
by fluidity
tkaraszewski wrote:
Sat Sep 12, 2020 10:54 pm
Maybe it's the video angle I'm seeing but there looks to be more curvature on the rear end of your stabiliser indicating it needs to be rotated 180º in the horizontal plane and also checked that it's curvy side is down?