Locking ferulle joint.

Locking ferulle joint.

Post by Zephy » Thu, 05 Apr 2007 22:27:18


Hey folks,

I just bought 2 new masts and am quite happy with them so far.  :)
reading over the paperwork that came with them it says repeatedly to make
sure when rigging to fully insert the ferrule.
this got me thinking.
Although I have never had any trouble with making sure that the ferrule is
not fully inserted, and I know a piece of electrical tape around the outside
will work,  I though, why can't mast manufactures make the mast with a
locking joint.

so here is what I came up with.

Most masts have 2 plugs in the top section of the mast to trap air inside
and keep water out,
why not add a 3rd plug to the top half,  pushing this plug in the bottom
end.  This plug however would look like a donut with a threaded hole.
This could be all plastic, or could be a plastic plug with a stainless nut
set in the center.

then on the bottom half of the mast,  instead of the flat plastic cap that
usually goes on the top of the lower half,  have a cap that has a plastic
bolt that matches the thread of the donut.

Then you insert the 2 pieces together normally, and too close the last 1/2 -
1/4  inch gap between top and bottom you would simply twist the 2 pieces to
engage the threads and lock the mast together.

the biggest issue I can see with this idea is that sand could get in the
threads and make it hard to thread the masts.  To me this really isn't a big
issue, because you already have to make sure there is no sand in there.

the other worry would be that when screwing the 2 pieces together the donut
would come down rather than the bottom going up.
Put a bit of glue on the outside of the donut when you push it into the top
section to make sure it stays put when you thread the 2 sections together.

what do you guys think?

Dave

 
 
 

Locking ferulle joint.

Post by sm.. » Thu, 05 Apr 2007 23:07:35

Very simple solution-

Drill a small hole in the mast through the top section and through the
ferrule, one side only.  Install a push pin similar to what was used
on early boom extensions.  The mast snaps together and won't separate
unless you push in the pin.

I've seen it done.  It's simple.  It works.  Why don't mast mfgs do
it?  I don't know.

sm


Quote:
> Hey folks,

> I just bought 2 new masts and am quite happy with them so far.  :)
> reading over the paperwork that came with them it says repeatedly to make
> sure when rigging to fully insert the ferrule.
> this got me thinking.
> Although I have never had any trouble with making sure that the ferrule is
> not fully inserted, and I know a piece of electrical tape around the outside
> will work,  I though, why can't mast manufactures make the mast with a
> locking joint.

> so here is what I came up with.

> Most masts have 2 plugs in the top section of the mast to trap air inside
> and keep water out,
> why not add a 3rd plug to the top half,  pushing this plug in the bottom
> end.  This plug however would look like a donut with a threaded hole.
> This could be all plastic, or could be a plastic plug with a stainless nut
> set in the center.

> then on the bottom half of the mast,  instead of the flat plastic cap that
> usually goes on the top of the lower half,  have a cap that has a plastic
> bolt that matches the thread of the donut.

> Then you insert the 2 pieces together normally, and too close the last 1/2 -
> 1/4  inch gap between top and bottom you would simply twist the 2 pieces to
> engage the threads and lock the mast together.

> the biggest issue I can see with this idea is that sand could get in the
> threads and make it hard to thread the masts.  To me this really isn't a big
> issue, because you already have to make sure there is no sand in there.

> the other worry would be that when screwing the 2 pieces together the donut
> would come down rather than the bottom going up.
> Put a bit of glue on the outside of the donut when you push it into the top
> section to make sure it stays put when you thread the 2 sections together.

> what do you guys think?

> Dave


 
 
 

Locking ferulle joint.

Post by Roger Jacks » Thu, 05 Apr 2007 23:07:59

Hi Dave,
Nice idea, but we have enough problems with getting our masts to bend
correctly at the ferrule, so adding anything inside that's solid is
going to cause some problems with the mast bend.
Vinyl electrical tape on the outside of the mast is still the best bet here.
It does not affect the bend of the mast at all as the tape is flexible,
and it keeps both sand and water out of the ferrule.
Anything that "screws together" inside the mast would not keep sand and
water out, and unless it's a flexible material, it would affect the mast
bend.
Hope this helps,
Quote:

> Hey folks,

> I just bought 2 new masts and am quite happy with them so far.  :)
> reading over the paperwork that came with them it says repeatedly to make
> sure when rigging to fully insert the ferrule.
> this got me thinking.
> Although I have never had any trouble with making sure that the ferrule is
> not fully inserted, and I know a piece of electrical tape around the outside
> will work,  I though, why can't mast manufactures make the mast with a
> locking joint.

> so here is what I came up with.

> Most masts have 2 plugs in the top section of the mast to trap air inside
> and keep water out,
> why not add a 3rd plug to the top half,  pushing this plug in the bottom
> end.  This plug however would look like a donut with a threaded hole.
> This could be all plastic, or could be a plastic plug with a stainless nut
> set in the center.

> then on the bottom half of the mast,  instead of the flat plastic cap that
> usually goes on the top of the lower half,  have a cap that has a plastic
> bolt that matches the thread of the donut.

> Then you insert the 2 pieces together normally, and too close the last 1/2 -
> 1/4  inch gap between top and bottom you would simply twist the 2 pieces to
> engage the threads and lock the mast together.

> the biggest issue I can see with this idea is that sand could get in the
> threads and make it hard to thread the masts.  To me this really isn't a big
> issue, because you already have to make sure there is no sand in there.

> the other worry would be that when screwing the 2 pieces together the donut
> would come down rather than the bottom going up.
> Put a bit of glue on the outside of the donut when you push it into the top
> section to make sure it stays put when you thread the 2 sections together.

> what do you guys think?

> Dave


 
 
 

Locking ferulle joint.

Post by pacspee » Fri, 06 Apr 2007 00:07:10

I kinda like it...

Even better than holding the two pieces together, you could force them
apart by backing out the threads, no more stuck masts!

Anyhow, most ferrules dont bend well anyway, I doubt a 3 or 4 inch
long piece of hardware is going to mess up the curve.

 
 
 

Locking ferulle joint.

Post by Zephy » Fri, 06 Apr 2007 00:55:37


Quote:
>I kinda like it...

> Even better than holding the two pieces together, you could force them
> apart by backing out the threads, no more stuck masts!

> Anyhow, most ferrules dont bend well anyway, I doubt a 3 or 4 inch
> long piece of hardware is going to mess up the curve.

Thanks Alex,

I didn't even think of the removal as part of the benefit.  But thinking
about it,  the setup would be more powerful pushing apart rather than
pulling together.  the plug is sliding into a decreasing diameter, and so it
would wedge tight, and not travel

I guess this could even be a retro fit on any existing mast,  or, an
accessory that someone like chinnok could sell.

Dave

 
 
 

Locking ferulle joint.

Post by Glenn Woodel » Fri, 06 Apr 2007 01:04:02


Quote:
>I kinda like it...

>Even better than holding the two pieces together, you could force them
>apart by backing out the threads, no more stuck masts!

>Anyhow, most ferrules dont bend well anyway, I doubt a 3 or 4 inch
>long piece of hardware is going to mess up the curve.

Tell that the the mast manufacturers. I suggested a three-piece mast a
while back so they would be much easier to store and the limitation
was that the ferrule alread caused a lot of problems with correct bend
and weight too.

Glenn

 
 
 

Locking ferulle joint.

Post by Zephy » Fri, 06 Apr 2007 01:30:48


Quote:

>>I kinda like it...

>>Even better than holding the two pieces together, you could force them
>>apart by backing out the threads, no more stuck masts!

>>Anyhow, most ferrules dont bend well anyway, I doubt a 3 or 4 inch
>>long piece of hardware is going to mess up the curve.

> Tell that the the mast manufacturers. I suggested a three-piece mast a
> while back so they would be much easier to store and the limitation
> was that the ferrule alread caused a lot of problems with correct bend
> and weight too.

> Glenn

If the bolt was made of plastic, and it had an inch of length before the
threading started I think that would allow for more than enough flex to
match the mast curve.  and plastic parts wouldn't really add all that much
weight to the mast either.

Maybe this is an accessory for the freerider,  but not the racer who's also
buying the non water absorbing footstraps.

Dave

 
 
 

Locking ferulle joint.

Post by Mamb » Fri, 06 Apr 2007 02:19:41


Quote:
> Very simple solution-

> Drill a small hole in the mast through the top section and through the
> ferrule, one side only.  Install a push pin similar to what was used
> on early boom extensions.  The mast snaps together and won't separate
> unless you push in the pin.

> I've seen it done.  It's simple.  It works.  Why don't mast mfgs do
> it?  I don't know.

> sm

A mast under load has some serious stresses already near the ferrule.  I
wouldn't be wanting to drill a hole that might cause a crack or failure.
You can bet no mast manufacturer would honor a warranty on such a mast
either.

FWIW, I use the electrical tape solution, and I still double check the join
before and after downhauling.

Cheers
Gary

 
 
 

Locking ferulle joint.

Post by sm.. » Fri, 06 Apr 2007 05:08:17

We're only talking a hole that's in the range of 3/16" diameter.
Circular holes are very good at transfering stress around them.

But regardless, I'm not suggesting that the consumer do this to their
mast.  You could, but I agree, it would probably void the warranty if
there were a failure at the ferrule.  What I'm suggesting is that it
is a very simple solution.  Mast mfg's are aware of the loads at the
ferrule, if there were a concern, they could easily beef up the lay-up
in the area of the hole (I seriously doubt that they would need to).

The point is, this is one potential, very simple, proven solution to
the problem- there are others.  However, the industry refuses to
addres the issue any farther than to say "make sure your mast is
together before you downhaul and if that's a problem, wrap some tape
around the joint."  Gimme a break!  Instead they could add about $2 to
the cost of the mast to ensure that you don't accidentally snap your
high-tech $400+ carbon fiber mast.

sm


Quote:


> > Very simple solution-

> > Drill a small hole in the mast through the top section and through the
> > ferrule, one side only.  Install a push pin similar to what was used
> > on early boom extensions.  The mast snaps together and won't separate
> > unless you push in the pin.

> > I've seen it done.  It's simple.  It works.  Why don't mast mfgs do
> > it?  I don't know.

> > sm

> A mast under load has some serious stresses already near the ferrule.  I
> wouldn't be wanting to drill a hole that might cause a crack or failure.
> You can bet no mast manufacturer would honor a warranty on such a mast
> either.

> FWIW, I use the electrical tape solution, and I still double check the join
> before and after downhauling.

> Cheers
> Gary

 
 
 

Locking ferulle joint.

Post by Roger Jacks » Fri, 06 Apr 2007 10:19:36

Hi Pacspeed,
Force them apart.....? If you use the tape on the outside, you don't
have to worry about forcing them apart.
Plus, if there's a water tap (hose bib) anywhere near your launch, the
"water pressure mast separator" works like a dream and does not damage
the ferrule like so many other "processes" that have the potential to
permanently damage the ferrule or at a minimum the "fit of the ferrule".
Plus, any "threaded" parts in WS gear that are not assembled permanently
(as in "locktited") are.
Hope this helps,
Quote:

> I kinda like it...

> Even better than holding the two pieces together, you could force them
> apart by backing out the threads, no more stuck masts!

> Anyhow, most ferrules dont bend well anyway, I doubt a 3 or 4 inch
> long piece of hardware is going to mess up the curve.

 
 
 

Locking ferulle joint.

Post by Dan Weis » Sat, 07 Apr 2007 01:41:24


Quote:

> >I kinda like it...

> >Even better than holding the two pieces together, you could force them
> >apart by backing out the threads, no more stuck masts!

> >Anyhow, most ferrules dont bend well anyway, I doubt a 3 or 4 inch
> >long piece of hardware is going to mess up the curve.

> Tell that the the mast manufacturers. I suggested a three-piece mast a
> while back so they would be much easier to store and the limitation
> was that the ferrule alread caused a lot of problems with correct bend
> and weight too.

> Glenn

You're right Glenn.  Single piece masts can be significantly lighter,
and the ubiquitous two piece mast was created to reduce shipping
costs, not to make it easier for sailors to stuff inside a quiver
bag.  Shipping an 8-9 foot box is far less expensive than a 16-18 foot
box as was necessary when masts were single piece.   Most
manufacturers have figured out how to work around the ferrule in terms
of bend and stiffness, but not all manufacturers have fiugured out how
to prevent masts from snapping from the point loading created by the
ferrule.
 
 
 

Locking ferulle joint.

Post by d.. » Sat, 07 Apr 2007 12:58:57


Quote:

> >I kinda like it...

> >Even better than holding the two pieces together, you could force them
> >apart by backing out the threads, no more stuck masts!

> >Anyhow, most ferrules dont bend well anyway, I doubt a 3 or 4 inch
> >long piece of hardware is going to mess up the curve.

> Tell that the the mast manufacturers. I suggested a three-piece mast a
> while back so they would be much easier to store and the limitation
> was that the ferrule alread caused a lot of problems with correct bend
> and weight too.

> Glenn

Interesting... I know someone making a part like this for a fishing
company... its a more tapered ferrule going to a straight section but
has plastic threads screwing into machined fiberglass threads...(joins
a 25 foot long tube about the size of the average RDM mast).  And then
there are plenty of 3 piece kids mast. Seems like a short reach to
combine the two ideas into a***together WS mast... then anyone
that makes mast knows that a little change in the lay up of the
ferrule changes the bend of the mast... so its not so difficult to
imagine that ferrules in a 3 piece mast would just need to be designed
to yield the correct flex and curve... trial and error... I like the
idea to...hey... I bet you could recess an "O" ring into the assembly
so that it was watertight...

Don

 
 
 

Locking ferulle joint.

Post by Zephy » Wed, 11 Apr 2007 04:24:31


Quote:


>> >I kinda like it...

>> >Even better than holding the two pieces together, you could force them
>> >apart by backing out the threads, no more stuck masts!

>> >Anyhow, most ferrules dont bend well anyway, I doubt a 3 or 4 inch
>> >long piece of hardware is going to mess up the curve.

>> Tell that the the mast manufacturers. I suggested a three-piece mast a
>> while back so they would be much easier to store and the limitation
>> was that the ferrule alread caused a lot of problems with correct bend
>> and weight too.

>> Glenn

> Interesting... I know someone making a part like this for a fishing
> company... its a more tapered ferrule going to a straight section but
> has plastic threads screwing into machined fiberglass threads...(joins
> a 25 foot long tube about the size of the average RDM mast).  And then
> there are plenty of 3 piece kids mast. Seems like a short reach to
> combine the two ideas into a***together WS mast... then anyone
> that makes mast knows that a little change in the lay up of the
> ferrule changes the bend of the mast... so its not so difficult to
> imagine that ferrules in a 3 piece mast would just need to be designed
> to yield the correct flex and curve... trial and error... I like the
> idea to...hey... I bet you could recess an "O" ring into the assembly
> so that it was watertight...

> Don

I thought about the O Ring just by itself as a solution to the issue.
Recess the O ring into the male portion and make a minor depression in the
top half so that the O Ring has to compress to fit the mast,  then once in
place it decompresses to fill the depression and produce a stronger friction
fit than most masts currently have.
I guess the issue there is that a recess or depression in the already thin
walls would cause structural issues on the top half of the mast.

Dave