[Captain Ahab Jr]

Wow this thread has taken a mind of its own

Not had a chance to go through the replies until now as I've been crossing my fingers, legs and eyes while waiting for some FIA crash test results to be relayed back to me where I was hiding under a desk back at the office.

Motorsport composite design/engineering is no more clever than what is done in other composite industry sectors. The biggest differences are we sail closer to the wind when pushing the limits of failure and timescales, do our research and development work while making new parts not before, also every task that can be done in parallel is which means we do stuff in days that other industries would take weeks or years to do.

Originally Posted by motion

I have tons of carbon fiber pieces on my various motorcycles and am always amazed at the overall positive marketing ability of this stuff. It doesn't seem very strong to me at all, and it seems to shatter, rather than deform or crack. What am I missing here?

Shiny carbon doesn't mean you are buying quality. Thin laminates, cheap resin with no UV protection voided surface finish hidden under thick clear lacquer is the norm. I can offer a couple of simple tips when buying your next parts, ask if the resin is UV resistant, if it isn't it will degrade and fade over time. First side of carbon part to look at is not the moulded shiny side but the unmoulded side, compare the definition of the unmoulded side to the moulded side, it should be well defined without bridging of material in corners. Hold it up to the light if you can see specs. of light through the weave then they have tried to skimp on material. Also ask if it full thickness carbon fibre one trick manufacturers use is to just use carbon on the outer surfaces and bulk up the rest of thickness using black fibreglass. Ask if it is vacuum cured ie cured in a bag under vacuum this creates a much stronger part.

Originally Posted by VincentVega

Cool stuff
I make small parts and repairs mostly on boats with epoxy and fiberglass. Pretty simple to work with once you get the basics.

Vincent, great stuff, I'm jealous, something I really want to do but have never found the time for, principles behind making a part at home using dry carbon with wet lay up resin ie resin applied by brush and those made using pre-preg ie resin impregnated fabric using an autoclave are exactly the same. The only big difference are the more higher tech more accurate approach allows you to push the limits of the structure closer to the edge of failure.

On an F1 car something like a nose of rear impact structure that has to pass impact test will be designed with a safety factor of 1.1. Not uncommon to take 3-4 versions of crash structure to a crash test and keep testing until one passes. The scatter of the results being the deciding factor. Other safety critical parts such wings and wishbones will have a higher safety factor of 1.5 to allow for unforeseen track load conditions. Full stress analysis, fatigue testing and proof testing will have been carried out on these parts before they see time on a track. At the other end of the spectrum bodywork which is so lightweight the paint makes up a 3rd of the total weight will be designed from experience learnt from years of trying to stop parts from cracking.

Originally Posted by Seahawk

I own a composite design, tooling, manufacturing and assembly business in North Carolina: VX Aerospace. We are small (15 employees) but have a great reputation in the industry.
Very interesting industry.

Seahawk, I salute you for owning a business, too much responsibility for me. Please post up more cool stuff that you make.

Originally Posted by 1990C4S

Perfect as in straight? There's still a lot of work to do on sticks, I am about to get into and try to improve the end product. There are way too many sticks breaking at critical moments.

I kow nothing about ice hockey sticks bit if budget allows I think my engineering approach to improve your sticks would be to make some prototype parts with a hollow upper handle section. Strain gauge the lower end of the handle shaft run the wires back to a small data logging module fitted inside the hollow handle section. This would record the real world stick loads as used in anger which could be used for stress analysis loads to would allow you to refine a break proof laminate.

If budget doesn't allow then try using high strength carbon with a good toughened epoxy resin that still keeps it properties at lower temps. The most probably cause for a stick breaking other than poor design or manufacturing is the laminate section strength/stiffness changing over too short a distance which is a green light for break here failure.

I've got a friend who designed stick for a top Austrian ice hockey team I can ask him what is approach was if you like.