BAMAR Furler?

Hi,

i have already had to replace 2 torque tubes on the bamar! and probably expect to carry on replacing them as time and milage goes on. We have done about 15000miles sailing with the system. We are on 130 amps!

unfortunatly like many things with Hanse this furler system is not actually suppost to be used to furl a headstay, wrong specification! The Bamar system that most of us have is a spherical self-alining furler! A spherical furler cannot handle the friction involved with a headstay and so that is why bolts fall out and torque tubes need replacing.

now hanse have stop using bamar, probably because they just realised it was the wrong spec! with all the warrenty claims, etc!

cheers,

david.
630#17

Hi,
Finally we also have the same problems!
Our Hanse dealer somehow fixed the motor to tube connection, but now the tube to tube connections started to fail. Already the first two tubes are holding with just one screw!!!
My opinion is that the screws fail because of shear forces along the lenght of the forestay (and not because of torque). This happens because the luff of the sail changes continuously while sailing because of stretch, while the luff tube do not stretch. While the sail is stretching under wind loads the tubes try to elongate, so the joint is subject to axial loads. The screws shear and fall out.
Now Balmar wants us to remove the tubes send them to their factory and install them after they correct them.
THIS CANNOT BE ACCEPTED SINCE MOST OF THE COST IS TO REMOVE THE TUBES. BESIDES THAT I DO NOT KNOW HOW THIS WORK CAN BE DONE.

@TAIMA: Do you have any pictures taken during this operation, just in case I have to do the job myself? (and ask the money from Hanse later)

Hi,

Finally and after a lot of pressure the Greek dealer of Bamar increased the diameter of the screws connecting the furler tubes to each other. I think they did a good job.
In the mean time Bamar is refusing to compensate their dealer because they claim that it is Hanse who should pay them. Bamar claims that Hanse chose to install a weaker furler than Bamar suggested, so they (Hanse) are responsible. I am waiting the official letter from Bamar! Most probably the Hanse dealer and the Bamar representative will resolve their case in court, unless Hanse accepts their fault and take the cost (a few thousands Euros).

After giving a lot of thought to the subject I think that my furler lasted more because I have carbon sails. There are two mechanisms of failure:
1)The weight of the jib. Every wave moves the heavy jib up and down
2)The elasticity of the jib. Every wind blow stretches the jib.
Both actions exercise longitudinal forces to the furler tube which result in shear forces to the screws holding the tubes together. After a while these fail. Carbon sails are both lighter and stress less under tension, so my furler was saved. 


Edited by panos - 27 December 2009 at 09:51

Dear Fellows

I didnt have this problem until we had the Atlantic crossing. The screws were seared two times in the crossing. we are studying other solutions now.

We have talked with a rigger with good knowledge of Sparcraft rigs in Gudeloupe Island and he said our furler is tearing the screws apart because the mast pumping. It looks it is a common issue on high aspect ratio Sparcraft rigs.

The issue is normally found either in the furler or in the lower sections of the aluminium profile. The screws were either loss or sheared like cheese because the stress concentration in the forestay when the mast pumps.

We have see a 630 in the Antigua , English Harbor Island.

He just modified the rig to put running backstays from the last spreader to both sides aft. This is used when reaching or motoring upwind and the mast is pumping. I think he has the same problem that our yachts but I could no locate a human bean sticking around the yacht to get more information.

I have to say I have never that problem before while cruising the med sea. Most owners will experience this problem while sailing in heavy swell upwind.

Ideas welcomed

ZENCAP

panos wrote: Hi,I dont see any clear reason why these screws unscrew. They should not get any load. The torque while furling/unfurling is taken by the shaft key, which is in perfect shape. Only while tensioning/untensioning the sail luff they could get some axial loads. My only explanation is that  they get unscrewd because of extreme vibrations during tacking.By the way we never sail with partially reefed jib. We either unfurl it all or else we use the storm jib on the inner forstay.After many experiments during the Aegean rally we found that we have to reef between 18 to 20 knots true. We throw the second reef at about 25 knots and over 30 we change to the storm jib. More wind than 34 knots (true) we did not encounter. We made 8.2 to 9.5 knots close hauled and 11.5 to 12.8 if at around 60 degrees (true).Yes the 630 can plane[IMG]smileys/smiley4.gif" align="absmiddle" alt="Big%20smile" /> on the waves. We need two waves to plane but then the speed climbs to 16.5 to 17 knots and stays there for long.

Dear Owners

We have got some interesting posts concerning this issue on the 531/540 subforum under the SPARCRAFT RIGGING PROBLEMS post.

ZENCAP