On Sun, 4 Jan 2009 10:01:50 -0500, "Eisboch" wrote:


"John H" wrote in message
.. .

What I'm looking for is some type of ball and socket bracket that would
allow side to side motion without transmitting the stress to the screws.


I think you'd end up with a very floppy bimini.

The type of brackets you have allow the bimini to be lowered (folded up when
underway).
They are not supposed to hold it rigid. That's what the straps are for.

Eisboch

Agree. But the straps prevent forward and backward motion. It's rock solid
that way. If there were straps going from the top right to the bottom left
and vice versa, then the swaying motion would be stopped also, or at least
most of it. But, walking around would be a pain.

It looks like a combination of this:
http://tacomarine.com/ccp51/media/im...y/F11-0177.gif

and this:
http://tacomarine.com/ccp51/media/im...l/F13-0301.gif

may do the job.

"John H" wrote in message
...
On Sun, 4 Jan 2009 10:01:50 -0500, "Eisboch" wrote:


"John H" wrote in message
. ..

What I'm looking for is some type of ball and socket bracket that would
allow side to side motion without transmitting the stress to the screws.


I think you'd end up with a very floppy bimini.

The type of brackets you have allow the bimini to be lowered (folded up
when
underway).
They are not supposed to hold it rigid. That's what the straps are for.

Eisboch

Agree. But the straps prevent forward and backward motion. It's rock solid
that way. If there were straps going from the top right to the bottom left
and vice versa, then the swaying motion would be stopped also, or at least
most of it. But, walking around would be a pain.

It looks like a combination of this:
http://tacomarine.com/ccp51/media/im...y/F11-0177.gif

and this:
http://tacomarine.com/ccp51/media/im...l/F13-0301.gif

may do the job.


Maybe I don't understand your concept. What you have pictured is a ball and
socket type of fitting that is *designed* to allow it to flop around. If
your idea is to tighten up on the socket so it clamps down hard on the ball
it might stiffen it up *however* all the forces due to wind, etc. will
still be imparted on the bracket screws. You mentioned they are screws,
not bolts with backing plates. IMO, you're going up with cracks in the
gunnels.

Too stiff is not always good. Wait, let me rephrase that.

It's not always desirable to mount something like a wind catching bimini in
a manner that it can't "give" a bit. All the forces will be transmitted to
the brackets. The straps provide *additional* fore and aft support, taking
much of the stress off the brackets. They are there with consideration that
you may have the bimini up while underway.

That's my opinion.

Eisboch

On Sun, 4 Jan 2009 10:22:10 -0500, "Eisboch" wrote:


"John H" wrote in message
.. .
On Sun, 4 Jan 2009 10:01:50 -0500, "Eisboch" wrote:


"John H" wrote in message
...

What I'm looking for is some type of ball and socket bracket that would
allow side to side motion without transmitting the stress to the screws.


I think you'd end up with a very floppy bimini.

The type of brackets you have allow the bimini to be lowered (folded up
when
underway).
They are not supposed to hold it rigid. That's what the straps are for.

Eisboch

Agree. But the straps prevent forward and backward motion. It's rock solid
that way. If there were straps going from the top right to the bottom left
and vice versa, then the swaying motion would be stopped also, or at least
most of it. But, walking around would be a pain.

It looks like a combination of this:
http://tacomarine.com/ccp51/media/im...y/F11-0177.gif

and this:
http://tacomarine.com/ccp51/media/im...l/F13-0301.gif

may do the job.


Maybe I don't understand your concept. What you have pictured is a ball and
socket type of fitting that is *designed* to allow it to flop around. If
your idea is to tighten up on the socket so it clamps down hard on the ball
it might stiffen it up *however* all the forces due to wind, etc. will
still be imparted on the bracket screws. You mentioned they are screws,
not bolts with backing plates. IMO, you're going up with cracks in the
gunnels.

Too stiff is not always good. Wait, let me rephrase that.

It's not always desirable to mount something like a wind catching bimini in
a manner that it can't "give" a bit. All the forces will be transmitted to
the brackets. The straps provide *additional* fore and aft support, taking
much of the stress off the brackets. They are there with consideration that
you may have the bimini up while underway.

That's my opinion.

Eisboch


OK, my explanation probably sucked. I'm not worried about fore and aft
motion, either while underway or at anchor. It's the side to side motion of
the bimini that puts stress on the mounting bracket, because there is not
enough play in the interface between the bimini frame and the deck bracket.
The side to side motion gets transmitted through the bracket to the
mounting screws.

I don't want to stop the side to side motion. I want it to be free, so that
stress will not be transmitted to the screws.

I'm thinking the ball is loose in the socket, but I've not seen it yet.

On Sun, 04 Jan 2009 10:35:46 -0500, John H
wrote:

OK, my explanation probably sucked. I'm not worried about fore and aft
motion, either while underway or at anchor. It's the side to side motion of
the bimini that puts stress on the mounting bracket, because there is not
enough play in the interface between the bimini frame and the deck bracket.
The side to side motion gets transmitted through the bracket to the
mounting screws.

"Side to side" motion is the most difficult to prevent because there
is typically no lateral bracing. The screws are working loose
because of the high stress on them, and they will crack the deck
eventually as others have pointed out. The answer is to through bolt
the fittings with backing plates and/or oversize fender washers.
That will solve the fitting problem and may reduce swaying some what.
Ultimately the answer is more bracing, with at least three attachment
points on each side. I'd get the recomendation of a good canvas shop
that does a lot of biminis.

John H wrote:
On Sun, 4 Jan 2009 10:01:50 -0500, "Eisboch" wrote:

"John H" wrote in message
...
What I'm looking for is some type of ball and socket bracket that would
allow side to side motion without transmitting the stress to the screws.

I think you'd end up with a very floppy bimini.

The type of brackets you have allow the bimini to be lowered (folded up when
underway).
They are not supposed to hold it rigid. That's what the straps are for.

Eisboch

Agree. But the straps prevent forward and backward motion. It's rock solid
that way. If there were straps going from the top right to the bottom left
and vice versa, then the swaying motion would be stopped also, or at least
most of it. But, walking around would be a pain.

It looks like a combination of this:
http://tacomarine.com/ccp51/media/im...y/F11-0177.gif

and this:
http://tacomarine.com/ccp51/media/im...l/F13-0301.gif

may do the job.

If I thought the bimini on a new boat would not hold up the stress while
underway or even from waves, I would talk to my dealer about finding a
better solution and/or providing backing plates and bolts.

But as far as the brackets you showed, I don't think those would reduce
the side to side movement, and would actually increase the movement.