Carbon fiber wrenches?

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Date: 24 Sep 2007 22:23:24
From:
Subject: Carbon fiber wrenches?

Why aren't tools like wrenches, allen keys, spoke wrenches, pliers,
chain-breakers, and car-jacks made from carbon fiber?

Or are they available?

Cost? Fragility? Lack of hardness? Strengh for size? Is it even
possible?

What about bicycle tire levers?

And what about nails, screws, nuts, and bolts? If cost were no object,
would a carbon-fiber nail even work?

An explanation adapted to the meanest understanding would be very
interesting, possibly using aluminum versus steel tools (or glass
wrenches or screws made of wood) to illustrate whatever the hell the
answers are.

Cheers,

Carl Fogel

Date: 26 Sep 2007 13:55:14
From: Greens
Subject: Re: Carbon fiber wrenches?

Date: 25 Sep 2007 20:45:49
From: Michael Press
Subject: Re: Carbon fiber wrenches?

In article
<0c2hf3ta5ikn96jpfbcuq96bm1q0cbahf8@4ax.com >,
carlfogel@comcast.net wrote:

> Why aren't tools like wrenches, allen keys, spoke wrenches, pliers,
> chain-breakers, and car-jacks made from carbon fiber?
>
> Or are they available?
>
> Cost? Fragility? Lack of hardness? Strengh for size? Is it even
> possible?
>
> What about bicycle tire levers?
>
> And what about nails, screws, nuts, and bolts? If cost were no object,
> would a carbon-fiber nail even work?
>
> An explanation adapted to the meanest understanding would be very
> interesting, possibly using aluminum versus steel tools (or glass
> wrenches or screws made of wood) to illustrate whatever the hell the
> answers are.

Two words. Crushing strength.

--
Michael Press

Date: 25 Sep 2007 18:43:15
From: Bill
Subject: Re: Carbon fiber wrenches?

Date: 30 Sep 2007 13:59:43
From: Tom \Johnny Sunset\ Sherman
Subject: Re: Carbon fiber wrenches?

Bill ??? wrote:
> <carlfogel@comcast.net> wrote in message
> news:0c2hf3ta5ikn96jpfbcuq96bm1q0cbahf8@4ax.com...
>> Why aren't tools like wrenches, allen keys, spoke wrenches, pliers,
>> chain-breakers, and car-jacks made from carbon fiber?
>>
>> Or are they available?
>>
>> Cost? Fragility? Lack of hardness? Strengh for size? Is it even
>> possible?
>>
>> What about bicycle tire levers?
>>
>> And what about nails, screws, nuts, and bolts? If cost were no object,
>> would a carbon-fiber nail even work?
>>
>> An explanation adapted to the meanest understanding would be very
>> interesting, possibly using aluminum versus steel tools (or glass
>> wrenches or screws made of wood) to illustrate whatever the hell the
>> answers are.
>>
>> Cheers,
>>
>> Carl Fogel
>
> Carl,
> I wasn't aware of your fondness for fishing. A carbon fiber rod is certainly
> a good choice for the target prey. Given a few hours I'll bet you bag your
> limit.
> Bill

POTM!

--
Tom Sherman - Holstein-Friesland Bovinia
A Real Cyclist [TM] keeps at least one bicycle in the bedroom.

--
Posted via a free Usenet account from http://www.teranews.com

Date: 25 Sep 2007 11:59:09
From: Jambo
Subject: Re: Carbon fiber wrenches?

<carlfogel@comcast.net > wrote in message
news:0c2hf3ta5ikn96jpfbcuq96bm1q0cbahf8@4ax.com...
> Why aren't tools like wrenches, allen keys, spoke wrenches, pliers,
> chain-breakers, and car-jacks made from carbon fiber?
>
> Or are they available?
>
> Cost? Fragility? Lack of hardness? Strengh for size? Is it even
> possible?
>
> What about bicycle tire levers?
>
> And what about nails, screws, nuts, and bolts? If cost were no object,
> would a carbon-fiber nail even work?

There will be minimum sizes at which carbon fiber components will be
effective, simply due to the practical size of the fibers themselves and
number of them required to achieve the load-bearing capacity of the
particular component.

A carbon fiber composite nail or screw can only contain relatively few
number of fibers of a dimension strong enough for any useful application;
the directional properties of a carbon fiber composite will dictate
multi-directional fibers in layers, to provide practical load bearing
capacity in all the directions required for a screw or nail (torsional,
axial, perpendicular), which will simply be impossible due to the size of
the screw or nail. Manufacturing of such small components (talking about
hardware store merchandise size here) will also be prohibitively expensive,
even if one can figure out a way to layer prepegs that small.

Compare this to metal nails or screws, where the isotropic properties of
metals enable load capacity to be imparted to the component in all
directions, the only limitation being the effective dimension of the
component with respect to the load (e.g. a nail will obviously be stronger
axially than perpendicularly, since in the former the effective load
carrying dimension of the nail is its length x cross-section area:
perpendicularly the effective loading dimension of the nail is its cross
section area only).

All that is with respect to the carbon fibers themselves. There is also the
issue of the matrix which holds the fibers together - epoxy or variants
thereof. There are also minimum thicknesses for these to be effective in
holding the fibers together, as well as providing some protection for the
fibers in terms of impact damage in directions different from the duty load
(think of bike forks, e.g. of non-duty loads will be impact on the fork legs
due to sticks, rocks, car bumper, storage rack). For such small components
as nails or screws, it will be almost impossible to have sufficient matrix
volume.

Another issue is friction - carbon fiber composites are not designed for
friction duty. There isn't a polymer matrix that can equal the hardness of
metals and as such, any application that involves regular rubbing contact
(chain breakers, pliers, wrenches) will result in a short-lived component.

It's possible to manufacture CF composite anything, if cost and effort are
no object - the question is whether they will be of practical use.

There are such things as metal matrix composites, of course, which are
different animals altogether. However, there are still the issues of
minimum sizes and manufacturing difficulties.

Date: 25 Sep 2007 15:33:26
From: bjw@mambo.ucolick.org
Subject: Re: Carbon fiber wrenches?

On Sep 24, 9:23 pm, carlfo...@comcast.net wrote:
> Why aren't tools like wrenches, allen keys, spoke wrenches, pliers,
> chain-breakers, and car-jacks made from carbon fiber?
>
> Or are they available?
>
> Cost? Fragility? Lack of hardness? Strengh for size? Is it even
> possible?

Abrasion resistance, lack of surface hardness,
strength and stiffness in dimensionally limited
applications, poor machinability; don't need/can't
pay for the strength to weight ratio. CF tubed
bicycles achieve stiffness by oversizing the
tubing compared to steel tubes. Hard to do
that in the working surface of a tool.

Consider that carbon cranks are now common, and
aluminum cranks are ubiquitous, but there are no
successful carbon or aluminum botton bracket spindles
(unless they are greatly oversized).

> What about bicycle tire levers?

Plastic tire levers are common, so CF tire levers
are possible, but also more expensive than necessary.

> And what about nails, screws, nuts, and bolts? If cost were no object,
> would a carbon-fiber nail even work?

A carbon fiber dowel could hold things together
when used as a pin. However, if you made a CF nail
the same dimensions as a steel nail, when you
hammered on it, the buckling force that wants
to make a steel nail bend would snap the CF nail
like a twig.

CF is a bit like wood, which is very strong in certain
applications and not in others depending on the
applied force.

Surface qualities and machinability (which are
related) would make threaded CF parts a pain in
the ass to use even if the threads could be cut
precisely and hold their shape, which I doubt.

> An explanation adapted to the meanest understanding would be very
> interesting, possibly using aluminum versus steel tools (or glass
> wrenches or screws made of wood) to illustrate whatever the hell the
> answers are.

Ben

Date: 25 Sep 2007 17:06:46
From: Clive George
Subject: Re: Carbon fiber wrenches?

<bjw@mambo.ucolick.org > wrote in message
news:1190734406.584020.183850@22g2000hsm.googlegroups.com...

> A carbon fiber dowel could hold things together
> when used as a pin. However, if you made a CF nail
> the same dimensions as a steel nail, when you
> hammered on it, the buckling force that wants
> to make a steel nail bend would snap the CF nail
> like a twig.

ISTR some demonstration of plastic nails which fired them into the thing to
be joined - they weren't hammered. This was some time ago though and I've no
idea if the concept made it into production.

cheers,
clive

Date: 25 Sep 2007 13:25:13
From: Jon_C
Subject: Re: Carbon fiber wrenches?

On Sep 25, 2:33 am, Ryan Cousineau <rcous...@sfu.ca > wrote:

> The first thing I would say is that steel is great. It has, for example,
> aluminum beat silly when it comes to strength/weight ratios. But not all
> of steel's strength is needed in places like bike frames: the most
> important limit to a steel frame's weight is probably the minimum wall
> thickness that will let it be safely welded, and that will not render it
> suceptible to "beer-canning" from incidental contact on the side of the
> tubes.
>
> Sufficient volumes of aluminum to make a bike frame have fewer such
> problems, and thus manage to avoid being beer-can thin while still
> requiring less mass of metal to make a functional frame.

Weight for weight aluminums and steels are pretty close in tensile
strength (ie when pulled like string).
If you take say two 1 oz, 12" long wires, one of aluminum and one of
steel, they'll both be able to lift approx the same weight before
snapping. **However the aluminum wire will be much more rigid**.
The reason is that aluminum's abut 1/3 as dense as steel so our 1oz
12" wire will have a *larger diameter* which makes it better able to
resist bending forces.

It's the same principal that, weight for weight, makes a tube stiffer
than a solid bar, a larger tube stiffer than a smaller tube and why a
ruler is only bendy in one direction. The further you move the
material out from the center, the more 'leverage' it hasto resist
bending and the stiffer it becomes.

So that's why carbon fiber is so useful, it's low density lets you use
very wide, deep frame members, making them stiff without getting too
heavy and without ending up with incredibly thin fragile walls.

Date: 25 Sep 2007 08:50:45
From: Peter Cole
Subject: Re: Carbon fiber wrenches?

carlfogel@comcast.net wrote:
> Why aren't tools like wrenches, allen keys, spoke wrenches, pliers,
> chain-breakers, and car-jacks made from carbon fiber?
>
> Or are they available?
>
> Cost? Fragility? Lack of hardness? Strengh for size? Is it even
> possible?
>
> What about bicycle tire levers?
>
> And what about nails, screws, nuts, and bolts? If cost were no object,
> would a carbon-fiber nail even work?
>
> An explanation adapted to the meanest understanding would be very
> interesting, possibly using aluminum versus steel tools (or glass
> wrenches or screws made of wood) to illustrate whatever the hell the
> answers are.

A CF handled wrench would certainly be possible and perhaps advantageous
in some applications. If you think about it, CF cranks are essentially
the same as CF wrenches. Various forms of reinforced plastic have been
used for handles for a long time. Usually these reinforcements are of a
type that doesn't preclude automatic (injection) molding. To get the
full strength and stiffness of fiber reinforced plastic you need long
fibers, and it's been difficult so far to automate the forming of that
kind of material -- hence, it's expensive.

Fiberglass handled tools are pretty common (hammers, pruning saws, etc.)
as are things like ladders. There's probably no reason these couldn't be
made from CF, other than expense. There are some applications where CF
might be too stiff, have too low impact tolerance, or be too
electrically conductive, where other fiber (glass, Kevlar) might just be
a better match.

Plastic fasteners, including screw fasteners, are also practical and
desirable in some applications. Again, for fiber reinforced, getting
long fibers into the critical areas (threads) is problematic, as is
molding. Some predict that nano-carbon will change this.

Plastics have low hardness, are subject to creep and solvent and UV
attack, and have limited temperature range. These qualities limit the
ability to replace metals in many applications.

CF has impressive specs, but those have to be viewed in an anisotropic
context. Consider your CF nail. Once the nail was in, it probably would
handle the tension and shear load well, if the fibers were lengthwise.
How you could drive it in is another matter. Unidirectional CF is very
weak off-axis, so the nail would buckle and mushroom. To counter this,
you'd have to support the hoop stresses somehow, as by wrapping fiber
around the long axis. Complicated nail. Making fasteners out of
composites is kind of an oxymoron, the real beauty of composites is
eliminating fasteners (and joints).

Date: 25 Sep 2007 12:50:35
From: Jon_C
Subject: Re: Carbon fiber wrenches?

On Sep 25, 12:23 am, carlfo...@comcast.net wrote:
> Why aren't tools like wrenches, allen keys, spoke wrenches, pliers,
> chain-breakers, and car-jacks made from carbon fiber?
>
> Or are they available?
>
> Cost? Fragility? Lack of hardness? Strengh for size? Is it even
> possible?
>
> What about bicycle tire levers?
>
> And what about nails, screws, nuts, and bolts? If cost were no object,
> would a carbon-fiber nail even work?
>
> An explanation adapted to the meanest understanding would be very
> interesting, possibly using aluminum versus steel tools (or glass
> wrenches or screws made of wood) to illustrate whatever the hell the
> answers are.
>
> Cheers,
>
> Carl Fogel

It's all about pressure (and cost and bulkiness but I'll skip that).

Carbon fiber composites are relatively soft. That means they can't
resist pressure very well, just like your skin (and unlike steel). To
feel the effect of pressure on a material, press the flat end of a
pencil against your skin...doesn't hurt right. Now press the pointy
end just as hard...
Pain in your skin is relative to pressure. Pressure is what dent's/
damages/snaps materials.

The reason a carbon fiber wrench would fail is that all the force is
applied to the nut via the 2 (or 6) corners that it's contacting.
That's a very small surface area recieving a very large force and that
means a high pressure that would would dent/chew up the wrench's
surface.

As noted above, a steel insert would correct the problem by spreading
the pressure and applying it to the rest (carbon fiber part) of the
wrench. It's like putting a penny on your hand and pressing it with
the pointy end of your pencil - the pressure's spread and now your
hand can resist the force withuot damaging it's surface.

Carbon fiber's great in any application where forces can be resisted
over a largish area (bike frames, possibly car jack frames) but poor
at resisting very localised forces (pedal spindles, allen wrenches).

Date: 25 Sep 2007 08:34:10
From: _
Subject: Re: Carbon fiber wrenches?

On Mon, 24 Sep 2007 22:23:24 -0600, carlfogel@comcast.net wrote:

> Why aren't tools like wrenches, allen keys, spoke wrenches, pliers,
> chain-breakers, and car-jacks made from carbon fiber?
>

Hell, make 'em out of wood. Thats a composite, so we are told.

Or papier-mache; easier to mould...

The point being that certain materials' qualities are better for certain
circumstances - and the toughness of metal is very very good for those
needed for spanners.

Date: 25 Sep 2007 11:37:06
From: M-gineering
Subject: Re: Carbon fiber wrenches?

_ wrote:
> On Mon, 24 Sep 2007 22:23:24 -0600, carlfogel@comcast.net wrote:
>
>> Why aren't tools like wrenches, allen keys, spoke wrenches, pliers,
>> chain-breakers, and car-jacks made from carbon fiber?
>>
>
> Hell, make 'em out of wood. Thats a composite, so we are told.
>
> Or papier-mache; easier to mould...
>
> The point being that certain materials' qualities are better for certain
> circumstances - and the toughness of metal is very very good for those
> needed for spanners.

Rixen Kaul did a CF reinforced moulded chainbreaker once. It was very
springy, ie crap

--
/Marten

info(apestaartje)m-gineering(punt)nl

Date: 25 Sep 2007 06:33:26
From: Ryan Cousineau
Subject: Re: Carbon fiber wrenches?

In article <0c2hf3ta5ikn96jpfbcuq96bm1q0cbahf8@4ax.com >,
carlfogel@comcast.net wrote:

> Why aren't tools like wrenches, allen keys, spoke wrenches, pliers,
> chain-breakers, and car-jacks made from carbon fiber?

I see what you're doing...

First guess? The strength:cost ratio of CF is high, and none of those
things need to be light.

Allen keys have a limited volume in which they can put material (that
is, the wrench has to fit into the bolt head), and in that application,
virtually nothing can touch the strength of the harder grades of steel
(less malleable, more brittle).

> Or are they available?

I did find a CF vernier caliper:

http://www.sussextools.co.uk/show_product.php?pinf=0-374-0-5-59

> Cost? Fragility? Lack of hardness? Strengh for size? Is it even
> possible?

A CF car jack would be relatively easy, but in a screw-jack I'm sure
you'd make the screw components out of steel, because I doubt that CF
has as good a wear hardness as steel in that application.

I'd be surprised if a CF allen key was even possible, but maybe they can
make certain CF formulations hard enough to tolerate the forces.

A CF wrench would be a hilarious-looking object, I suspect: super light,
but with an enormous wrench head. At that, the sage constructor might
well embed a tool steel (hard) set of tool faces in the wrench head, so
that the first bolt head in the wrench didn't chew through the tool
faces.

> What about bicycle tire levers?

Hmmm...that would be interesting. Not so much for the lightness but the
stiffness. But I worry about whether there would be enough material in
the thinnes part...

> And what about nails, screws, nuts, and bolts? If cost were no object,
> would a carbon-fiber nail even work?

Tricky. You could trivially make a nut and bolt out of CF (think of
plastic versions of same, widely available as super-low-strength
fasteners), but it would likely have a fraction of the strength of steel.

Consider Ti fasteners, which exist, and which save weight, but which are
less strong than comparable steel fasteners. They are used in places
where the designer assumes the extra strength of steel is wasted. And
yet strangely enough, Ti bolts often seem to break...

> An explanation adapted to the meanest understanding would be very
> interesting, possibly using aluminum versus steel tools (or glass
> wrenches or screws made of wood) to illustrate whatever the hell the
> answers are.

The first thing I would say is that steel is great. It has, for example,
aluminum beat silly when it comes to strength/weight ratios. But not all
of steel's strength is needed in places like bike frames: the most
important limit to a steel frame's weight is probably the minimum wall
thickness that will let it be safely welded, and that will not render it
suceptible to "beer-canning" from incidental contact on the side of the
tubes.

Sufficient volumes of aluminum to make a bike frame have fewer such
problems, and thus manage to avoid being beer-can thin while still
requiring less mass of metal to make a functional frame.

Damon Rinard says it thus:

"Bicycles are generally stiffness-critical structures, i.e. by the time
you've added enough material to make it stiff enough it is nearly always
strong enough."

http://www.sheldonbrown.com/rinard/carbonqa.htm

Carbon fibre is way out on this curve: modern CF construction leads to a
product that is way less dense than Al or steel, but which is so light
and strong it hardly matters. Cut a typical CF frame open, and the walls
are almost certain to be thicker than, say, typical steel walls (which
in the case of Columbus tubing, seem to range from 0.5 to 1.0 mm):

http://www.equusbicycle.com/bike/columbus/columbuschart.htm

One of the most notable examples of this principle of how much volume
you have to make the part work is pedal spindles. In that application,
steel is the standard on parts of all quality levels, because only it is
strong enough to easily handle the forces. Aluminum and CF would
essentially be impossible in that application. Titanium is marginal:
Most Ti pedal spindles carry a weight limitation.

Of course, materials differ in many ways, not just stiffness, strength,
and density.

--
Ryan Cousineau rcousine@sfu.ca http://www.wiredcola.com/
"I don't want kids who are thinking about going into mathematics
to think that they have to take drugs to succeed." -Paul Erdos