[Curious_George]

hey i've been looking into building a carbon frame so far i've been keeping up with many of the threads from other sites and have amassed a wide variety of info so far. Wanted to know if you guys had any info what so ever on

-the threads of the guys building their own stuff and how they did it
-where and what to buy for carbon threads and epoxy

so far i've found a distributor www.tapplastics.com

any info of link would help

 

[LMC]

try www.sollerpaddles.com

how do u plan to compress/cure the fabric?

 

[ThePriceSeliger]

PM BCD. He makes Carbon DH frames.

 

[Curious_George]

try www.sollerpaddles.com

how do u plan to compress/cure the fabric?

i've seen many videos of people using pressurized pumps to spread out the excess epoxy...but to my knowledge the best method would be to "cook it" since you can make the innards of polystyrene melt away and save quite some weight...to my knowledge acetone can also melt the polystyrene out of the carbon mold

Carbon heated in the range of 1500-2000 °C (carbonization) exhibits the highest tensile strength , while carbon fiber heated from 2500 to 3000 °C (graphitizing) exhibits a higher modulus of elasticity

Question #1: 24K vs 12K vs 6k plz read the bottom and comment

plz read: http://www.corecomposites.com/media/penetrationImpactTestResults.pdf


Q #2 plain weave or 2x2 twill?

plain is defined as:the warp and weft are aligned so that they form a simple criss-cross pattern.

2x2 twill: It is made by passing the weft thread over one or more warp threads and then under two or more warp threads and so on, with a "step" or offset between rows to create the characteristic diagonal pattern.

 

[buildyourown]

Check Wick's aircraft and Aircraft spruce. They have lots of supplies for diy carbon.
Unless you use prepreg (read: expensive) you still need a way to push the excess epoxy out. Cooking it just speeds the setup time or kicks your prepreg.

 

[Curious_George]

look at it this way, how do bike manufacturer's do it?

i doubt they use the old vaccum trick

 

[wiscodh]

unless you have 100's of thousands of dollars laying around, you will not be making it like the bike companys. You need presses, molds, cnc's, storage, an understanding of composites, ect.

Quite frankly i think you have none of that right now.

That shouldnt stop you from learning about it tho. Carpetfibres are an amazing material when used correctly. When used incorectly they are scary.

If i recall correctly BCD used a wet layup with a vac bag. Right now, i think this would be your only option. Unless you can figure out someway to pressureize your oven and make an autoclave.

 

[Curious_George]

well the oven is no prob as I have one here at the university, same as the CNC machine....the storage is no prob since they have rooms especially for that

the rest is bits and pieces

 

[wiscodh]

awsome, you have some of the logistics figured out.

How do you want to make it? Saying like the other bike companys will not fly for you and your low production manufacturing. Unless you have money to burn on tooling.

Do you have a design?

Have you taken a class in composites? What is your area of study?

It is not bits and peices really. How you plan on manufacturing is key to your design process and the logistics of getting everything ready to have a disred outcome. Anyone can slap together some carbon, its not that hard. Making good composite parts, thats the hard part.

 

[beaverbiker]

use a wet lay up with a male mold. bag it and bleed the excess resin into bleeder cloth. done deal.

 

[buildyourown]

I don't think BCD uses vacuum bags. I asked him about it and I seem to recall him saying that it was to much hassle for what he does. Too bad he's been out of the loop for a bit, I'm sure he'd chime in.
IIRC, he uses premade tubes and makes the lugs out of prepreg. No bag needed. No oven needed.

The most common method I've seen for homebuilts is a male mold made from some type of foam. Either make the mold removeable or disolve it with a solvent (gasoline). Or, make 2 halves, and clamshell them together. Once you get 1 layer cured up, the shell will be ridgid enough to handle. Bond it to it's other half and wrap it as one piece for all subsequent layers.

 

[LMC]

well the oven is no prob as I have one here at the university, same as the CNC machine....the storage is no prob since they have rooms especially for that

the rest is bits and pieces

if you do have access to the oven facilities then you may want to look into prepregs, more expensive? yes! less hassle though. IIRC they work out about 20% more than dry fabric

www.prepregs.com

for vacuum pumps, vac bagging film etc.. try here

www.avt-composites.com

heres a how to.. althought he used the electrical tape method for compression...

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

 

[LMC]

The most common method I've seen for homebuilts is a male mold made from some type of foam. Either make the mold removeable or disolve it with a solvent (gasoline). Or, make 2 halves, and clamshell them together. Once you get 1 layer cured up, the shell will be ridgid enough to handle. Bond it to it's other half and wrap it as one piece for all subsequent layers.

yeah thats what i would advise, its the easiest way to get your idea into action, foam is cheap and easy to shape.

look at model aircraft builders sites for foam, blue closed cell foam. it has to be rigid enough to withstand the compression while curing.

check out www.bmeres.com the finish on his frame is incredible

google carbon mike, another good example of this technique

 

[Curious_George]

so prepreg is partially cured fibers with resin
these are the advantages of prepreg

* Very precisely controlled fiber/resin ratios
* Highly controlled tack and drap (in thermoset matrices)
* Controlled resin flow during the cure process
* PREPREG materials can be produced and stored
* Can be used in hand lay-up production

info on prepreg :
http://www.lavender-ce.com/wp-content/uploads/guide-to-prepregs.pdf

 

[Curious_George]

scientific study on prepref shows that

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TWK-44CMPNB-3&_user=458507&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_version=1&_urlVersion=0&_userid=458507&md5=a19ed069726145c0552febb612ecab32

1. Prepreg bonded composite single lap joints have a higher load carrying capacity than those prepared by neat resins. This is also true for the residual load carrying capacity after 90 days air+UV and seawater+UV conditioning.

2. Fiber orientation and ply stacking sequence have a considerable effect on the load carrying capacity of prepreg bonded composite single lap joints. The unidirectional prepreg adhesives (P1 and A2/P1/A2) perform much better than the angle ply prepreg adhesives (P2 and A2/P2/A2).

3. Environmental conditioning has a significant effect on the reduction of the load carrying capacity of all specimens. UV radiation alone can reduce the load carrying capacity by about 9.0–15.8%. The presence of seawater makes things even worse. 22.2–41.1% of the load carrying capacity are lost after 90 days of seawater+UV radiation attacks. Using carbon fiber prepregs may be a viable alternative for offshore applications.

4. Finite element analysis shows that the reason for the better performance of unidirectional prepregs P1 and A2/P1/A2 is due to the reduced peel stress and interfacial shear stress.

5. Using softer resin can reduce the axial stress and peel stress, but cannot reduce the interfacial shear stress. This implies that using softer neat resin may reduce the cohesive failure but not the adhesive failure.

 

[Curious_George]

i dont think it could be better explained than this:

CHECK IT:http://www.patentstorm.us/patents/5204042/description.html

 

[Hack On Wheels]

Darn it, now you have me wanting to build a carbon fiber frame all over again! This always comes up once in a while... but I still haven't gotten around to actually doing it. I'm really interested to see how it goes for you!

 

[fluider]

i dont think it could be better explained than this:

CHECK IT:http://www.patentstorm.us/patents/5204042/description.html

I do think . Google provides unrestricted access to the full-versions of all patents stored in their www.google.com/patents DB. Full-version means figures, images, tables etc included, not only text. Imagine studying DW-Link patents without illustrations provided, that would be final (fatal) fantasy .
Your document is here

 

[Curious_George]

I do think . Google provides unrestricted access to the full-versions of all patents stored in their www.google.com/patents DB. Full-version means figures, images, tables etc included, not only text. Imagine studying DW-Link patents without illustrations provided, that would be final (fatal) fantasy .
Your document is here

cool beans, I couldn't find dw link by simply typing it i the search so I looked it up searching his name and it came up, but i couldn't find the fsr patten

any comments/suggestions for the carbon build

 

[dhkid]

i hope you aren't serious about using resin transfer to make a bike frame. that's just making things a lot harder for your self.

if you have excess to an oven in your uni, there are bound to be ppl who are experts in that field, go ask them. you will get far more information then you would over here.

 

[Nately27]

theres some info on this page: http://www.lahrcycles.com/2005_12_01_archive.html.

scroll all the way to the bottom for some build pictures.

 

[Curious_George]

i hope you aren't serious about using resin transfer to make a bike frame. that's just making things a lot harder for your self.

if you have excess to an oven in your uni, there are bound to be ppl who are experts in that field, go ask them. you will get far more information then you would over here.

I had a couple of tutorials on resin transfer, and no I won't be utilizing this technique,

 

[Curious_George]

theres some info on this page: http://www.lahrcycles.com/2005_12_01_archive.html.

scroll all the way to the bottom for some build pictures.

thanks for the additional info!!!

 

[Freddy Salgado]

http://www.instructables.com/id/How-I-built-a-carbon-bike-frame-at-home-and-a-bam/

Dont know if you checked this out yet boss, pretty basic but it seems like a good method for one off's. You can take it to the next level with vacum bagging instead of the electric tape step. Good luck!

 

[Killerbarbies]

have you read this thread http://www.ridemonkey.com/forums/showthread.php?t=177748

if not, go there, and PM CarbonMike the frame builder. He's Slovak but his English is excellent.

 

[fluider]

have you read this thread http://www.ridemonkey.com/forums/showthread.php?t=177748

if not, go there, and PM CarbonMike the frame builder. He's Slovak but his English is excellent.

I'm not sure if CarbonMike will have time to answer his questions. I was in short email communication with him 6 months ago but it had to end as CarbonMike was to busy. Unfortunately he removed the in-process photos of the frame from his site carbonmike.sk .
You could also visit Brano Meres's site; bmeres.com ; that can provide you useful links.

 

[MrPlow]

Tried frameforum?
Pre Preg is nice but expensive and you need an autoclave.
Unidirectional cloth is the go I reckon. So long as you lay it up right.
Either way you have to vac it to remove any voids. This is the most important bit (more so than what you use: prepreg/wet).