Hobie Forums :: View topic - Mast Support Fail

I discussed the issue with engineers... There are some variables I could imagine.

- Sailing loads will cause the mast to lean back and cause drum wear. Sheeting out and then furling should correct that one.
- Position changes in the drum location on the mast (production or slip during use).
- Wear of the pin inside the mast base.
- Flex at the cup to crossbar connection.
- Bearing plate position on the V2 crossbar.
- Bend or out of column bearing plate.

Possible corrective adjustments considered:

- V frame tension pulling up on the cup could raise (fraction) the drum relative to the bearing plate. It is possible that the V frame is pushing down. V2 adjustment should normally be a net fit, neither pushing down or pulling up.
- Raising the base pin inside the receiver, possibly with washers under the pin hardware inside the cup.
- Adding material on top of the pin or inside the mast base (teflon chip similar to Hobie 14 / 16?)
- Replacing the base or re-positioning.

Author:	kayakman7 [ Sat Aug 18, 2012 12:56 pm ]
Post subject:	Re: Mast Support Fail
SailScott wrote: Off topic, but just a bit, how do you drain your mast cup after sailing/washing? (I keep a 3' length of irrigation/polypipe tubing on board to siphon it out.) Scott I drilled a hole in it, tapped the hole, and fitted a plug in it. J

Author:	KayakingBob [ Sat Aug 18, 2012 2:08 pm ]
Post subject:	Re: Mast Support Fail
I keep a very flexible sponge with a 18" leash on it that I push into the mast hole, usually using half a Hobie paddle to push it all the way down, then pull it back out and squeeze it out. Twice will get almost all the water out. This is after flushing the cup with plenty of fresh water.

Author:	chrisj [ Sat Aug 18, 2012 3:59 pm ]
Post subject:	Re: Mast Support Fail
If you're one of those who remove their amas/akas after sailing, it's easy just to flip the boat over and let it drain.

Author:	Tom Kirkman [ Sat Aug 18, 2012 6:05 pm ]
Post subject:	Re: Mast Support Fail
Turkey Baster. One squeeze/release and it's dry.

Author:	SailScott [ Sun Aug 19, 2012 12:19 am ]
Post subject:	Re: Mast Support Fail
Turkey baster!?! (Great idea!... and well in time for TurkeyDay!) Thanks! Scott

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Mast Support Fail http://www.hobie.com/forums/viewtopic.php?f=71&t=44081	Page 6 of 9

Author:	Slaughter [ Tue Apr 23, 2013 5:32 am ]
Post subject:	Re: Mast Support Fail
Here we are again. I just did a few measurements and a review of the V2 mast arrangement. As Matt said, the turnbuckle will not adjust the mast height. There is no adjustment therefor I can only conclude that there must be a difference in the position of the mast drums on the mast on the V1 arrangement to the V2 arrangement. ie: the masts must be different. My mast drum is positioned in the same spot as Stringy's. Mine is a V2, his is a V1. On mine, the distance from the top surface of the mast receiver, to the top face of the stainless bearing plate ( down the hole ) is 260mm. As you can see from this photo, this dimension should be 260mm ( plus a gap ), not the 250mm as shown. In conclusion, I reckon a V2 hull must be 10mm deeper than a V1 hull and I have a V1 mast fitting in a V2 mast receiver causing wear. ( I'd love to be wrong ) Over to you Matt.

Author:	mmiller [ Tue Apr 23, 2013 8:14 am ]
Post subject:	Re: Mast Support Fail
I'll ask our tech and engineer staff to have a look.

Author:	mmiller [ Tue Apr 23, 2013 11:45 am ]
Post subject:	Re: Mast Support Fail
I discussed the issue with engineers... There are some variables I could imagine. - Sailing loads will cause the mast to lean back and cause drum wear. Sheeting out and then furling should correct that one. - Position changes in the drum location on the mast (production or slip during use). - Wear of the pin inside the mast base. - Flex at the cup to crossbar connection. - Bearing plate position on the V2 crossbar. - Bend or out of column bearing plate. Possible corrective adjustments considered: - V frame tension pulling up on the cup could raise (fraction) the drum relative to the bearing plate. It is possible that the V frame is pushing down. V2 adjustment should normally be a net fit, neither pushing down or pulling up. - Raising the base pin inside the receiver, possibly with washers under the pin hardware inside the cup. - Adding material on top of the pin or inside the mast base (teflon chip similar to Hobie 14 / 16?) - Replacing the base or re-positioning.

Author:	NOHUHU [ Tue Apr 23, 2013 9:38 pm ]
Post subject:	Re: Mast Support Fail
mmiller wrote: I discussed the issue with engineers... There are some variables I could imagine. - Sailing loads will cause the mast to lean back and cause drum wear. Sheeting out and then furling should correct that one. - Position changes in the drum location on the mast (production or slip during use). - Wear of the pin inside the mast base. - Flex at the cup to crossbar connection. - Bearing plate position on the V2 crossbar. - Bend or out of column bearing plate. Possible corrective adjustments considered: - V frame tension pulling up on the cup could raise (fraction) the drum relative to the bearing plate. It is possible that the V frame is pushing down. V2 adjustment should normally be a net fit, neither pushing down or pulling up. - Raising the base pin inside the receiver, possibly with washers under the pin hardware inside the cup. - Adding material on top of the pin or inside the mast base (teflon chip similar to Hobie 14 / 16?) - Replacing the base or re-positioning. Thanks Matt. Please thank the Hobie Geeksquad for us too. That's a pretty good list of the variables. I might add "over time, stretching and deformation of the hull (bottom) can slightly lower the mast cup if enough positive turnbuckle pressure is applied." Ultimately, the position (and any subsequent movement) of the glued furling ring is the most important factor. Together with the rest, it could contribute to the small but important differences we see from hull to hull, and sail to sail. There are slight issues with a couple of the provided solutons though: - "Sheeting out and then furling should correct that one." This may only work in North America. In Australia, the men don't know how to furl. - "Raising the base pin inside the receiver, possibly with washers under the pin hardware inside the cup." It can take quite a few washers to make this calibration, as we initially found when adding stainless fender washers under the sail to raise it. My feeling is that these base screws are too brittle and that raising the step plate will loosen or weaken the connections where forces to the pin are frankly, incredible. Having seen a couple thick base pins shear would lead me to rule out that fix on my boat. Can we ask you for a little more info? 1. Is the female mast (or the male for that matter) designed to rest and spin on the bottom of the cup, or float over it, suspended slightly on the pin? 2. Can Hobie provide the critical measurements for the distance between the mast base (either gender) and the bottom of the furling ring? It seems to me, this is the first thing we all need to check... Again - Mahalo Nui

Author:	Slaughter [ Wed Apr 24, 2013 5:05 am ]
Post subject:	Re: Mast Support Fail
Yeah, thanks Matt. But could I also add to NOHUHU's 2 questions with : Q3. On the mast, what is the correct measurement from the Hobie factory for the distance from the mast drum to the base of the mast ( shown in my photo as 250mm ). I believe it should be 260mm. I have just made the following modification the the mast bearing plate. I've added a 48mm diameter x 10mm PVC thermoplastic washer shaped spacer to the bearing plate. The mast drum now has a 2mm gap between the mast drum and the mast receiver. I also double checked that the pin inserts the mast by 10 to 15mm. The mast now furls beautifully and may even take a little getting used to. ( ........also need to get that sand out ).

Author:	mmiller [ Wed Apr 24, 2013 8:35 am ]
Post subject:	Re: Mast Support Fail
Great idea! The pin is supposed to support the mast, but hey... if that works. I'll ask for the factory specs.

Author:	Tom Kirkman [ Thu Apr 25, 2013 5:46 am ]
Post subject:	Re: Mast Support Fail
I was on the phone with Dan Ketterman yesterday about some things pertaining to the TriFoiler. Somehow we got on the subject of the Island kayaks and discussing the V-Truss he said it wasn't meant to be used for raising or lowering the mast support structure. I mentioned that I set my V-Truss by bringing everything into contact, and then giving the turnbuckles 1/2 turn (expand) to snug everything in place and he said, "That sounds about right." Using the V-Truss to push the hull up or pull it down only puts undue stress on the hull that can lead to problems. The V-Truss isn't there to serve that purpose.

Author:	PassWind [ Thu Apr 25, 2013 8:09 am ]
Post subject:	Re: Mast Support Fail
NOHUHU wrote: - "Sheeting out and then furling should correct that one." This may only work in North America. In Australia, the men don't know how to furl. Also, I think it would be furling and then sheeting Down Unda since things spin backwards south of the equator Nah .. nevermind

Author:	NOHUHU [ Thu Apr 25, 2013 2:48 pm ]
Post subject:	Re: Mast Support Fail
But I think they wind their sails on counterclockwise there.

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Author:	Slaughter [ Thu Apr 25, 2013 4:46 pm ]
Post subject:	Re: Mast Support Fail
NOHUHU & PassWind - But we are also upside down here..........so therefore it still spins in the same direction Tom & Matt - Although I now have a sail that easily spins on it's base, and effectively works as it was designed to work.....it still isn't right. Because the pin only recesses into the mast by only 10mm, not the 20mm as required, the load on the pin in bending is now greater. Tom, is your AI a V2 model and if so could you please see if your mast measures the same as mine in the photos. I'm 'sticking to my guns' in say'n that the mast drum should be glued in at 260mm and not 250.