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Composite parts building.



 
 
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  #1  
Old December 5th 07, 07:23 AM posted to rec.bicycles.tech
webhead[_2_]
external usenet poster
 
Posts: 61
Default Composite parts building.

Hey all,

I'm sort off drawn to the whole carbon frame building thing but doing
that is easier said than done.

I figured it's probably a bad idea to start messing with carbon cloth
in the first place, it really expensive and doesn't handle too easy
from what I've seen. I'd like to use a different kind of fiber to get
the hang of it and maybe later use carbon cloth. Johan Musseeuw
(former cyclist) started building frames using Flax fiber. I thought
It was a mistake but it's not. It looks weird as well:
http://www.museeuwbikes.be/images/article_la/58.jpg
A lot of people seem to make boat/car/plane parts with fiberglass.

So I'd like to start by building the most easy thing I can think of: a
piece of tube and maybe a drop handlebar later on.

Experiences and testimonies anyone?
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  #2  
Old December 5th 07, 09:43 AM posted to rec.bicycles.tech
Chalo
external usenet poster
 
Posts: 5,093
Default Composite parts building.

webhead wrote:

I'm sort off drawn to the whole carbon frame building thing but doing
that is easier said than done.

I figured it's probably a bad idea to start messing with carbon cloth
in the first place, it really expensive and doesn't handle too easy
from what I've seen. I'd like to use a different kind of fiber to get
the hang of it and maybe later use carbon cloth.


Fiberglass is cheap, but it's horrible itchy stuff to work with.
Kevlar is easier than carbon or glass, but it's expensive. A strong
natural fiber like ramie might be good-- soft and relatively easy to
work. Ramie is much stronger than linen (flax) or cotton. Either
ramie or linen would be relatively easy to find as woven cloth for
laying up a composite structure.

So I'd like to start by building the most easy thing I can think of: a
piece of tube and maybe a drop handlebar later on.


I hope you've had a look at Damon Rinard's page on homebuilding carbon
frames:

http://sheldonbrown.com/rinard/carbon_fiber.htm

Chalo
  #3  
Old December 5th 07, 10:57 AM posted to rec.bicycles.tech
dabac[_82_]
external usenet poster
 
Posts: 1
Default Composite parts building.


webhead Wrote:
Hey all,

I'm sort off drawn to the whole carbon frame building thing but doing
that is easier said than done.

I figured it's probably a bad idea to start messing with carbon cloth
in the first place, it really expensive and doesn't handle too easy
from what I've seen. I'd like to use a different kind of fiber to get
the hang of it ...So I'd like to start by building the most easy thing
I can think of: a piece of tube and maybe a drop handlebar later on.


Pretty much all production of CF or FG items are done either AROUND a
core (that may either be left in place or removed by various means) or
IN a mold. So something like a drop handlebar is definitely going to be
a challenge as a DIY project...
Building your own TT helmet around a sacrifical core could probably be
a good first project, or maybe a streamlined, weatherproof CF saddle
"bag"?

A tempo bar might also be reasonably within reach for a DIY project.


--
dabac

  #4  
Old December 5th 07, 12:12 PM posted to rec.bicycles.tech
webhead[_2_]
external usenet poster
 
Posts: 61
Default Composite parts building.

On Dec 5, 10:57 am, dabac dabac.314...@no-
mx.forums.cyclingforums.com wrote:
webhead Wrote:

Hey all,


I'm sort off drawn to the whole carbon frame building thing but doing
that is easier said than done.


I figured it's probably a bad idea to start messing with carbon cloth
in the first place, it really expensive and doesn't handle too easy
from what I've seen. I'd like to use a different kind of fiber to get
the hang of it ...So I'd like to start by building the most easy thing
I can think of: a piece of tube and maybe a drop handlebar later on.


Pretty much all production of CF or FG items are done either AROUND a
core (that may either be left in place or removed by various means) or
IN a mold. So something like a drop handlebar is definitely going to be
a challenge as a DIY project...
Building your own TT helmet around a sacrifical core could probably be
a good first project, or maybe a streamlined, weatherproof CF saddle
"bag"?

A tempo bar might also be reasonably within reach for a DIY project.

--
dabac


Thats a good idea, a TT helmet crossed my mind as well.
I though about making a wire mesh first (from something like chicken
run fence wire mesh, thin wire big gaps) and drape my fiber around it
in narrow ends, much like handlebar tape. That way I would have a form
which would be hollow and lightweight.

I saw that page from Damon Rinard but that's complex stuff to begin
with. For instance I'm missing info on the usable polymers. Is an
epoxy two compound resin the only polymer that's sufficient in terms
of structural rigidity? I've known people to construct a boat hull
with sheets of fiberglass and polyester coatings, sanding and
smoothing it out in between layers but a boat hull is not a thin
handlebar or frametube.
I'll be sure to wear gloves and long sleeves when I should handle
fiberglass

webhead
  #5  
Old December 5th 07, 01:08 PM posted to rec.bicycles.tech
dabac[_83_]
external usenet poster
 
Posts: 1
Default Composite parts building.


webhead Wrote:

I though about making a wire mesh first (from something like chicken
run fence wire mesh, thin wire big gaps) If you want to go that route there are better types of mesh available.

Try a type used behind ventilator grilles to prevent rodents and bugs
from entering for instance. There are several several different gauges
and gap sizes available.
It's not that easy to get such a design nice and symmetric though, at
the very least you should consider adding some ribs and other braces for
it to keep its shape during lay-up.

webhead Wrote:

.. and drape my fiber around it in narrow ends, much like handlebar
tape. Although that would work it would lend itself to unnecessary weight in

the finished item. In FG manufacture you need a certain overlap for good
adhesion between layers, and that method would give more an excessive
amount of overlap. As big as possible w/o wrinkling is the ticket.

And I still think you'd be better off sculpting your helmet out of
Styrofoam, sealing the surface against solvents and then doing your
layup on that. It'll retain its shape far better and give you a better
shot at coming out with a symmetrical product.
webhead Wrote:
...For instance I'm missing info on the usable polymers. Is an epoxy two
compound resin the only polymer that's sufficient in terms
of structural rigidity?

Rigidity is a joint characteristic of material properties and design
features. There are lots of stuff out there that you can build strong
enough components out of as long as you adapt the wall thicknesses,
exterior dimensions (and perhaps internal bracers as well) to suit. But
if you want a strength/weight ratio that makes it worthwhile to leave
alloys behind then you're pretty much limited to the exotics.

webhead Wrote:
...I've known people to construct a boat hull
with sheets of fiberglass and polyester coatings, sanding and
smoothing it out in between layers but a boat hull is not a thin
handlebar or frametube. apparently you've never seen a racing yacht up close...


But the thing is simply that for most people the weight/strength ratio
of the material that goes into a boat isn't critical enough to merit the
extra cost of going to CF and epoxy. OTOH FG and polyester can easily be
shaped into double-curved surfaces, which is a feature that is quite
desirable in boat building.
webhead Wrote:
...I'll be sure to wear gloves and long sleeves when I should handle
fiberglass.


While that is a sensible thing it isn't the right priority. First
protect your brain, then your hands. Get a GOOD mask, one capable of
handling solvents and hydrocarbons. A simple dust filter is OK for the
sanding but it's nowhere near enough for the actual resin work.


--
dabac

  #6  
Old December 5th 07, 01:37 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 249
Default Composite parts building.

On Dec 5, 1:23 am, webhead wrote:
Hey all,

I'm sort off drawn to the whole carbon frame building thing but doing
that is easier said than done.

I figured it's probably a bad idea to start messing with carbon cloth
in the first place, it really expensive and doesn't handle too easy
from what I've seen. I'd like to use a different kind of fiber to get
the hang of it and maybe later use carbon cloth. Johan Musseeuw
(former cyclist) started building frames using Flax fiber. I thought
It was a mistake but it's not. It looks weird as well:http://www.museeuwbikes.be/images/article_la/58.jpg
A lot of people seem to make boat/car/plane parts with fiberglass.

So I'd like to start by building the most easy thing I can think of: a
piece of tube and maybe a drop handlebar later on.

Experiences and testimonies anyone?


you could also try bamboo and epoxies to build lets say a simple
single speed bike. nothing fancy. check what calffee bikes did. it is
pretty awesome
http://www.calfeedesign.com/bamboo.htm
carlos
http://www.bikingthings.com
  #7  
Old December 5th 07, 02:51 PM posted to rec.bicycles.tech
Peter Cole
external usenet poster
 
Posts: 1,360
Default Composite parts building.

webhead wrote:
Hey all,

I'm sort off drawn to the whole carbon frame building thing but doing
that is easier said than done.

I figured it's probably a bad idea to start messing with carbon cloth
in the first place, it really expensive and doesn't handle too easy
from what I've seen. I'd like to use a different kind of fiber to get
the hang of it and maybe later use carbon cloth. Johan Musseeuw
(former cyclist) started building frames using Flax fiber. I thought
It was a mistake but it's not. It looks weird as well:
http://www.museeuwbikes.be/images/article_la/58.jpg
A lot of people seem to make boat/car/plane parts with fiberglass.

So I'd like to start by building the most easy thing I can think of: a
piece of tube and maybe a drop handlebar later on.

Experiences and testimonies anyone?


If you read the description, the "flax" is actually a flax fiber/CF mixture.

A summary of current natural fiber composites:
http://www.compositesworld.com/ct/is.../February/1183

A couple of descriptions of home-made CF frames:
http://www.damonrinard.com/howibuil.htm
http://www.bmeres.com/carbonframe1.htm

Messing about with epoxy is a lot of fun (and really messy). I've not
done CF (yet), but I've done a fair amount with glass (mostly boat
building). Glass is cheap and relatively easy to work with, the main
nastiness comes during sanding. Epoxy is much more expensive than
polyester resin, but is easier to laminate. I've seen a variety of
cloth/fibers used with resin, for non-structural almost anything goes,
but for things like bike components fiber material and layup orientation
become critical. There's tons of information on the web, Mr. "webhead",
check it out -- but maybe your first application shouldn't be handlebars!
  #8  
Old December 5th 07, 04:55 PM posted to rec.bicycles.tech
Scott Gordo
external usenet poster
 
Posts: 943
Default Composite parts building.

On Dec 5, 8:51 am, Peter Cole wrote:
webhead wrote:
Hey all,


I'm sort off drawn to the whole carbon frame building thing but doing
that is easier said than done.


I figured it's probably a bad idea to start messing with carbon cloth
in the first place, it really expensive and doesn't handle too easy
from what I've seen. I'd like to use a different kind of fiber to get
the hang of it and maybe later use carbon cloth. Johan Musseeuw
(former cyclist) started building frames using Flax fiber. I thought
It was a mistake but it's not. It looks weird as well:
http://www.museeuwbikes.be/images/article_la/58.jpg
A lot of people seem to make boat/car/plane parts with fiberglass.


So I'd like to start by building the most easy thing I can think of: a
piece of tube and maybe a drop handlebar later on.


Experiences and testimonies anyone?


If you read the description, the "flax" is actually a flax fiber/CF mixture.

A summary of current natural fiber composites:http://www.compositesworld.com/ct/is.../February/1183

A couple of descriptions of home-made CF frames:http://www.damonrinard.com/howibuil....rbonframe1.htm

Messing about with epoxy is a lot of fun (and really messy). I've not
done CF (yet), but I've done a fair amount with glass (mostly boat
building). Glass is cheap and relatively easy to work with, the main
nastiness comes during sanding. Epoxy is much more expensive than
polyester resin, but is easier to laminate. I've seen a variety of
cloth/fibers used with resin, for non-structural almost anything goes,
but for things like bike components fiber material and layup orientation
become critical. There's tons of information on the web, Mr. "webhead",
check it out -- but maybe your first application shouldn't be handlebars!- Hide quoted text -

- Show quoted text -


Meres does a carbon/bamboo bike as well:
http://www.bmeres.com/bambooframe.htm
  #9  
Old December 5th 07, 04:57 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 1,299
Default Composite parts building.

On Dec 5, 1:23 am, webhead wrote:
Hey all,

I'm sort off drawn to the whole carbon frame building thing but doing
that is easier said than done.

I figured it's probably a bad idea to start messing with carbon cloth
in the first place, it really expensive and doesn't handle too easy
from what I've seen. I'd like to use a different kind of fiber to get
the hang of it and maybe later use carbon cloth. Johan Musseeuw
(former cyclist) started building frames using Flax fiber. I thought
It was a mistake but it's not. It looks weird as well:http://www.museeuwbikes.be/images/article_la/58.jpg
A lot of people seem to make boat/car/plane parts with fiberglass.

So I'd like to start by building the most easy thing I can think of: a
piece of tube and maybe a drop handlebar later on.

Experiences and testimonies anyone?


Fiberglass is cheap and easy to work with. I'd get really, really
thin sheets of fiberglass cloth and some blocks of foam, and carve the
shape of what I wanted into the foam. When you're happy with the
mold, fiberglass over it.
  #10  
Old December 5th 07, 05:00 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 1,299
Default Composite parts building.

On Dec 5, 4:57 am, dabac
wrote:

or maybe a streamlined, weatherproof CF saddle "bag"?


I've worked with fiberglass in other situations, and have considered
making something out of carbon fiber a few times. I never did for a
variety of reasons, and the lack of need for anything in carbon that
wouldn't be really difficult has always been one. You may have just
inspired me...
 




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