Gyr

Hi, I am planning to design and build my own fan unit, it will have a center hub machined from Aluminum with a number of carbon fiber blades inserted into the hub, my problem is I have never formed anything from carbon fiber before.
Has anyone any experience in working carbon fiber or can advise me what, where, when or how please, it is something that I would like to do for myself rather than go to the professionals.
I have tried to draw a very rough sketch just to give an idea of blade shape don’t laugh plz.

Gyr

i am unable to upload pics error 8000ffff how do i overcome this and yes i'm new to posting lol.

seanreit

My Feedback: (60)

Hey guys, this fella has done the leg work, see here:

http://www.rcuniverse.com/forum/m_66...tm.htm#6671571

jsf125

My Feedback: (12)

Hi, Gyr

I have worked with carbon before, and it is fairly straight forward as long as you have a plan of action i.e. ( In regards to a fan blade where the orientation of the weave of the fabric in relation to the span of the blade should be something carefully looked at.) I have never made fan blades out of carbon, but you are going to need a mold. The mold can be hand made from a prototype fan blade, but since you have modeled it in SW then use this to your advantage and take a look at the picture I have attached. I used to own a couple DS51's which are full carbon fan units. As you can see, the molds for these fans are machined from solid aluminum stock in order to maintain the sharp edges that the fan unit contains. I would personally advise this method for mold development due to the fact that you will be making a fan blade where precision and consistent reproducibility is critical. I have also attached an exaple of the carbon work I have previously done for one of my own projects.

If you want to take a look at the page with the carbon fans, here is the home page address => http://www.schuebeler-jets.de/


The following are some links that might help you decide what you would like to do. I am not sure how much composite work you have done, so please don't take my suggestions as an insult as this is not my intent. I have personally found these sources helpful in the past and may be able to help you as well, so here they are.

As far as mold making and working with carbon/ glass, here is a useful page with tutorials which detail the basics. => http://cstsales.com/tutorials.html

Here is another link that is very descriptive, and does a good job of running through the process of mold making => http://www.fibreglast.com/contentpag...ction-170.html

Here is a nice collection of related topics dealing with the construction and fabrication of composite parts => http://www.fibreglast.com/contentpag...chures-23.html


Here is something interesting I found in regards to the physical properties of carbon that you may find interesting and helpful to help decided the orientation of the cloth in relation to the span of the blade, =>

"Carbon fiber has a very high strength to weight ratio, meaning that for another material of the same weight, it is likely to be much stronger. But carbon fiber is a fibrous material, meaning that the fibers are all aligned in a single direction. This can affect strength if used improperly.

Because the fibers are aligned, carbon fiber has different strength amounts - depending on the direction that force is applied at. For example, rope is very strong if you pull, but very weak if you push. Carbon fiber is very strong in both compression and tension, but is much weaker in bending (force from the side). It is like trying to break a stick - breaking it at the center is much easier than by pulling it from the sides. So when using carbon fiber, make sure all force is only applied longitudinally."




Anyway, Hope this helps. Good luck with you project and feel free to ask anytime.

Brandon

Gyr

Thanks for that Brandon exactly what i was hoping for, i don't have much experience with moulding c/f but i persevere. you have given me a lot to look into so will keep me busy for some time.
Thanks once again Martin.

jsf125

My Feedback: (12)

Glad I could help, and I hope everything works out for you. Be sure to let us all know how things turn out!

Brandon