Carbon Tubing

[Craig_Charlton]

Last season I developed and tested a carbon fibre suspension system and I am working on implementing it this season. Unfortunately the company that supplied us with our composite tubing last season went bust. Has anybody used or know a reliable company/manufacturer that provides a good product?

Thanks

Craig

[BenB]

McMaster-Carr sells carbon tubing (and fabric and a few other things). I think the tubing is pre-hardened and comes in a variety of sizes. If you call them they can probably tell you specifics about the tubing. They are normally really helpful with things like that. I've never used it before, but I came accross it once.

[Mike Sadie]

just for future reference, what company was it that went out of business? Here are two I know of, possibly one of which you are referring to.

www.carbonfibertubeshop.com (http://www.carbonfibertubeshop.com) - crazy, i know

www.cstcomposites.com (http://www.cstcomposites.com) - from what I've seen on their site, they have excellent materials, but I have heard it is very pricey and in Australia. Some of the windings they make are straight-up sexy.

Just a word of advice. Be sure to avoid pultruded tubes if you can, because they have a considerably lower carbon/resin ratio than wound tubes. I have seen wound tubes with carbon/resin ratios around 95%. Pultruded is more common, and likely what you will find at McMaster, but it cant hurt to investigate.

[damonlemmon]

Check here for carbon tubes:

http://www.acp-composites.com/acp-tube.htm

We have had good luck with them.

[Craig_Charlton]

BenB. Last season we used Woolmer Forest Composites, the company went bust or something like that, they have been taken over now but dont do the size tubing that we need. Thanks for all your help guys

[Alastair Clarke]

Craig,

Try Carbonology.com. We've found them to be quite useful and helpful etc in the past

Regards

Alastair

[LU-Hetrick]

We have used Mclean Quality Composites for the past 2 years. They have many stock sizes to pick from and offer cheap (relatively) pricing.

Maclean Quality Composites (http://www.macqc.com/)

Ryan Hetrick
Lehigh University FSAE
Brakes, Chassis, Suspension

[TomF]

Delft has been using tubing from Prince fibre tech (http://www.princefibretech.com/). Located in the Netherlands, so I am not sure about shipping costs, but we are very pleased with their quality and support. And they are relatively cheap as well!

[Dave M]

http://www.aerosleeves.com/

[emerjer]

sup DaveMo

[trippjm]

Not to steer this thread off course from suppliers, but does anyone actually weave their own carbon tubing?

[flavorPacket]

TU graz did their own on their 07 car, but i think they're the only ones.

[TG]

Originally posted by trippjm:
Not to steer this thread off course from suppliers, but does anyone actually weave their own carbon tubing?

What do you mean by weave? Do you mean does anybody do a braid on a mandrel or a filament winding? Roll-wrapping is another (cheaper) option that is commonly used in the manufacturing of golf clubs and bicycle tubes.

[trippjm]

I should've been more clear and said 'manufacture', rather than 'weave', as there are several methods for construction. By weave, I mean filament winding.

[Mike Sadie]

I know Ohio State, and probably at least a handful of other teams have made intakes from carbon braid. If you made it straight, it could suffice for a suspension tube. But comparing cost, weight, and strength, I think purchasing wound tubes is the way to go for significant load-bearing members.

Here is an article about Cannondale using carbon braid for bike frame tubes. I know this is a shameless plug, but we are trying to sell some A&P braid - check the For Sale section for more details.

I'd be interested in how much consistency you could get out of tubes roll-wrapped in house.

[onemayonaise]

I've made our carbon fibre arms by wrapping, but I have to say that it is quite difficult to obtain a good result. After a few tries I decided to wrap the tube with a greater thickness and then lather it to the required dimension.
these are 15.0 mm I.D. and 18.0 mm O.D. and were tested in tension and compression, with failure results of about 4000 N and 7000 N respectively (...but with the tension test we noticed a problem in the arm cap bonding...).

if you are interested about times, the wrapping of eight bars of one meter each required about a day, and the lathering about two days...

[murpia]

[QUOTE]Originally posted by onemayonaise:
these are 15.0 mm I.D. and 18.0 mm O.D. and were tested in tension and compression, with failure results of about 4000 N and 7000 N respectively (...but with the tension test we noticed a problem in the arm cap bonding...).[QUOTE]
Care to elaborate on the layup used? Material spec, number of wraps, fibre orientation, resin type etc.?

Also, has anyone attempted to include the end-inserts in the layup process rather than bond them in afterwards? If so was it successful?

Regards, Ian

[Christopher Catto]

by lathering you mean working on a lathe?? (tornio?)

if so, I am a bit perplexed. Carbon fibre should not really be machined in any way. Lancia rally team did this in the 80s and it is now a bit frowned upon. the machining process kind of ruins the fibre because the cutting knife rips very small pieces off, like if you shave downwards a shaver rips your facial hairs instead of cutting them perfectly. so even in steel a bolt thread cut on the lathe is worse than a rolled thread. but with carbon, the results are even worse due to the fact that the fibres and resin etc must be in very nice uniform condition.

maybe you mean something else, if so, please explain

[onemayonaise]

@ Christopher Catto: yes, by lathering I mean working on a lathe (...sorry... I don't know exactly how to tell it in english but you know how it is in italian... http://fsae.com/groupee_common/emoticons/icon_biggrin.gif ). I know that machining carbon fibre is wrong, for this reason we use a thickness greater than the one required by FEA analysis (approx. 1.0 mm, while we have 1.5 mm). this is also the principal reason of our tests in tension/compression, in order to verify that such a process can guarantee our structural requests.
In these days I will try to collect some pictures of the tube before and after the lathe machining... http://fsae.com/groupee_common/emoticons/icon_wink.gif

@ murpia: the fibre is a woven fabric 0.4 mm thick wrapped six times around a calibrated steel mandrel, for a total thickness of 2.4 mm. Material is a prepreg Toray T300 with low temperature epoxy resin (it has been cured in a oven at 80?C for 6 hours instead of an autoclave...). Fibre orientation of the woven fabirc along the mandrel axis is +/- 45?.
...furthermore, I think that the end-insert bonding is the last of the problems in this procedure... http://fsae.com/groupee_common/emoticons/icon_wink.gif

[onemayonaise]

...Furthermore: I will like to add to all the problem explained by Christopher, the big problem of the carbon fibre dust created by the lathe machine...

...in the end: we tried to built our in-house suspension arms but, for the next car, I think that we will buy them...

[TG]

You will get better, more consistent parts with roll wrapping if you use a female mold with a pressure bladder/expandable mandrel instead of wrapping around a rigid mandrel. This way you can achieve autoclave quality parts without the use of an autoclave. Surface finish (if it matters) will also be markedly better, as well.

It will take a little experience with this method as you need to get the rolling of the material onto a non-rigid mandrel perfected, but the end results are more than worth it.

edit: little grammar mistake http://fsae.com/groupee_common/emoticons/icon_wink.gif

[flavorPacket]

TG is right. i'm fairly sure that's how most F1 teams currently do it, though they use several different types of weave in each component.

[carbon fiber]

i was looking for cheap www.ultralightcomposites.com (http://www.ultralightcomposites.com) carbon fiber tubes selling on the internet..i am a hobbiest for carbon fibers.

[df_fsmb]

We think a CFRP manufacturer just wanted to sell us some tubes for much higher price as we are the University.

They want 100EUR / meter for filament wound tubes. These tubes surely have required bending modulus to be strong in buckling, but as I am looking at prices on the web, it seems much too much.

I found a manufacturer who offer filament wound tubes for less than 100EUR/meter but with much larger OD.

What did you guys usually pay for such tubes, with fibres at various angles (filament wound, for example)?

[Lorenzo Pessa]

Do you have no way to get a sponsorship?

We get our carbon tubes from a fish rod manufacturer (who makes not only fish rods).

Initially he give us the aesthetical production wastes (the same mechanical propriety, some defects in the aesthetic ply).

[cvargas]

Originally posted by TG:
You will get better, more consistent parts with roll wrapping if you use a female mold with a pressure bladder/expandable mandrel instead of wrapping around a rigid mandrel. This way you can achieve autoclave quality parts without the use of an autoclave. Surface finish (if it matters) will also be markedly better, as well.

It will take a little experience with this method as you need to get the rolling of the material onto a non-rigid mandrel perfected, but the end results are more than worth it.

edit: little grammar mistake http://fsae.com/groupee_common/emoticons/icon_wink.gif

Trek uses compression molding to make their bicycle frames. It's a pretty good way to eliminate voids, but I wonder if anyone has had any experience with that and how it affects your fiber fraction vs matrix fraction? Any input?

[df_fsmb]

For teams with the same problems as we have: this looks like a promising dealer: http://www.carbonology.com/
They offer 10% off for Formula Student teams and they actually got recommended from some other dealer who did not have small diameters.

We recently did some tests on some really cheap tubes (12EUR/m) and bending modulus measured was around 45GPa. I expected it to be even lower for this stuff. We are looking forward to seeing the results for the Carbonology tubes we just ordered (specimen: plain and woven).

Will report soon