Moses fuselage to mast screws keeps coming loose

[joekitetime]

This is the way. You can also whack the fuselage with a hard rubber mallet. Or Ride for a couple of minutes and retighten once. then they will stay put. Basically its the head of the mast settling into the fuselage when under use.

Gunnar
[/quote]

This has worked for me as well. Ride, tighten, ride, maybe one more tighten, then she is set until you take everything apart again, in which case you rinse and repeat.

[taiguy]

This has been a minor problem for years
All moses masts all current fuses, (but unknown if race fuse and havock mast is the same)
I was driven mad by this annoying loose front bolt mystery,
and can tell you there was nothing I did not try, even adding grub screws through the side of the the fuse to clamp up the neck of the front securing bolt, all manner of washers, screw lock blue and red, no grease, arghhhh!
solution was more than easy, and has worked faultlessly since

board upside down mast attached
wingset fully assembled separately
ensure connection points are spotless
place wingset in place and listen for that clean sound of a good connection, no gritty crunchy sounds of trapped sand.
check washers are in place and screw up evenly, ideally use a high quality T handle allen head driver like this - https://www.ebay.co.uk/itm/Teng-Tools-T ... 0048076962
tighten to a good pressure only using 3 fingers on the bar,
the next step need to be done with either the wing covers left on or use a dry clean cloth in both hands to prevent transferring skin oil or sun tan oils to the wing surfaces.
grab both wings firmly and rock your weight back and forth over the wing set a few times,
you will then find that when you try and retighten the mast screws using the exact same force as before they will both tighten up just slightly more,
very satisfying,as its this simple routine that keeps the little buggers good and tight, 100% of my sessions

so the working hypothesis is that the wedge interface of the mast to fuselage isn't completely flush once you slide it on, and that additional force is required to "seat" the two pieces together, and then you can tighten the screws properly?

Just odd that I would think the screws themselves would bring the two pieces together firmly.

[FLandOBX]

so the working hypothesis is that the wedge interface of the mast to fuselage isn't completely flush once you slide it on, and that additional force is required to "seat" the two pieces together, and then you can tighten the screws properly?

Just odd that I would think the screws themselves would bring the two pieces together firmly.

I suppose the additional force required to "seat" the mast to fuselage makes more sense when one considers that many hydrofoils have an integrated (i.e., single piece) mast and fuselage. In order to compete favorably with those integrated systems, Moses needs to make certain to eliminate all potential play between the two parts. So the extra step to securely wedge the mast into the fuselage may be part of that process.

[grigorib]

I don’t think there’s any play there. Re-tightening the bolt after first session or two lasts very well. On OP picture a countersink bolt is pictured (those were used for 680 fuselage) and they are not that easy to tighten right and also they need to be re-tightened more compared to later version of fuselages using socket cap bolts.

Buttress thread would help too but it would bring its own challenges

[taiguy]

I don’t think there’s any play there. Re-tightening the bolt after first session or two lasts very well. On OP picture a countersink bolt is pictured (those were used for 680 fuselage) and they are not that easy to tighten right and also they need to be re-tightened more compared to later version of fuselages using socket cap bolts.

Buttress thread would help too but it would bring its own challenges

that picture was from my buddy's mast since he had it handy. I'm using the 710 fuselage with the socket cap bolts and washers. I don't even know where to source replacements for those in case I lose one/them.

[grigorib]

...
I'm using the 710 fuselage with the socket cap bolts and washers. I don't even know where to source replacements for those in case I lose one/them.

M6x25 (and 5mm shorter for kite fuselage) socket cap stainless - most of hardware store would have them.

When I had 680 the countersink bolts were loosening a bit more, yet again - tighten them after a first and second session and they’ll stay put

[taiguy]

M6x25 (and 5mm shorter for kite fuselage) socket cap stainless - most of hardware store would have them.

When I had 680 the countersink bolts were loosening a bit more, yet again - tighten them after a first and second session and they’ll stay put

I bought some washers and they didn't fit in the fuselage holes. The OEM washers are definitely thinner than the ones I'm finding in hardware stores.

[grigorib]

M6x25 (and 5mm shorter for kite fuselage) socket cap stainless - most of hardware store would have them.

When I had 680 the countersink bolts were loosening a bit more, yet again - tighten them after a first and second session and they’ll stay put

I bought some washers and they didn't fit in the fuselage holes. The OEM washers are definitely thinner than the ones I'm finding in hardware stores.

Not sure where to get the washers, sorry. I’d call the dealer

[Andrei23]

You need to take a washer for a 5mm bolt and drill a 6mm hole.

[a99]

Yes, Moses washers are smaller diameter (and totally overpiced as for diamonds price), but i found idea how adopt to as DIY, simple bought usual in all home stories a2 din127, din 5/5.0 size pack of washers which are not equal sides as you see and than simply little resized up more with 2 pliers and than did equal sides with hammer:) takes 10 minutes and easy than to wait shipping:)