Carbon Fiber Fan???

[Craig T]

I just bought sexy carbon fiber rain hats from Todd at Helion Composites. I was wondering - Is anybody making a carbon fiber fan yet.

I know there was discussion a couple years ago about this, but I can't find anybody selling one yet. The weight reduction in a spinning part might actually produce a small incremental performance gain, plus reduce wear on the belt.

[frankc]

I always wondered why a lighter weight material was not used for the non-pully part of the fan. Granted, Mg is pretty light as far as metal, but is metal needed for this application?

With folks going to great lengths to reduce every bit of rotational mass at the flywheel/pressure plate (Ti bolts), I am surprised I have not seen much in the way of reducing the mass of the fan, which rotates at a higher RPM than the crank.

[Craig T]

I'm sure there are those concerned with CF's durability in this application, but I doubt that's an issue. There are aircraft and Formula 1 parts made of CF under considerably more centrifical force and inertia than these fan blades.

We spend big money on CF parts for aesthetics only (and insignificant fixed weight savings). This would be a part that would look sexy and have a potential performance gain.

[Jerome74911S]

Craig T, what do you know about the fan in the photo you posted? Who made it?

It looks interesting, almost as if there is another (harder) material on the leading edge of each blade. I'd like to learn more.

[Craig T]

Originally Posted by Jerome74911S

Craig T, what do you know about the fan in the photo you posted? Who made it?

The picture is just a cut-and-paste that I found doing a Google search. It could be a VW fan, but I can't say for sure.

[JJ 911SC]

Originally Posted by Craig T

The picture is just a cut-and-paste that I found doing a Google search. It could be a VW fan, but I can't say for sure.

It could have been Carbonized…

How to cover parts in carbon fiber (fibre) by skinning or wrapping - YouTube

[Captain Ahab Jr]

looks like a carbon fibre fan to me and not wrapped or skimmed with a pretty pattern

[NOLAsc]

There's this...



from this thread: D-Zug Flat Fan Installation

[pkracer21j]

Hey Craig,
I think the fan you pictured was/is made by Marcus at kunststofftechnik-buehler dot de
When I met with him he had put the fan on hold due to stress issues. he may be making them again. drop him a line I'm sure he can help you or point you in the right direction.

[Craig T]

Originally Posted by pkracer21j

Hey Craig,
I think the fan you pictured was/is made by Marcus at kunststofftechnik-buehler dot de
When I met with him he had put the fan on hold due to stress issues. he may be making them again. drop him a line I'm sure he can help you or point you in the right direction.

Thanks. I checked his site. he doesn't list them in his product page. I dropped an email.

[JJ 911SC]

Originally Posted by Captain Ahab Jr

looks like a carbon fibre fan to me and not wrapped or skimmed with a pretty pattern

A close up shows metal as the base material

[Captain Ahab Jr]

Originally Posted by JJ 911SC

A close up shows metal as the base material

I don't think the grey areas are metal, to me this is what the edge of carbon looks like after it has been abraded or sanded

also the abraded mould split line where the blade meets the diameter is another possible give away its a real carbon fan

[JJ 911SC]

Maybe someone will claim ownership and give us the lowdown.

Should have read the e-mails after your post

[Dave Colangelo]

I had read some stuff about this in the past when I thought about replacing a fan I had with some chipped blades. One of the main issues with a carbon fiber fan is balance. Carbon fiber does not lay up as linearly as one might think so the weight could be very imbalanced. Although this can be corrected much like it is on a tire its just not worth it, the metal fans are significantly cheaper and much easier to make. I'm sure it could be made out of carbon but I would also be concerned with the heat in that area of the car. Carbon more specifically the resin used to lay up carbon does not stand up to heat that well, at least from what I have experienced. Would be cool looking on any note.

Regards
Dave

[Ronnie's.930]

Originally Posted by Dave Colangelo

I had read some stuff about this in the past when I thought about replacing a fan I had with some chipped blades. One of the main issues with a carbon fiber fan is balance. Carbon fiber does not lay up as linearly as one might think so the weight could be very imbalanced. Although this can be corrected much like it is on a tire its just not worth it, the metal fans are significantly cheaper and much easier to make. I'm sure it could be made out of carbon but I would also be concerned with the heat in that area of the car. Carbon more specifically the resin used to lay up carbon does not stand up to heat that well, at least from what I have experienced. Would be cool looking on any note.

Regards
Dave

Well, keep in mind that carbon fiber mufflers have been made for motorcycles for 15+ years, and the good ones hold up to the heat just fine (much hotter environment than the 911 fan sees).

[Dave Colangelo]

Originally Posted by Ronnie's.930

Well, keep in mind that carbon fiber mufflers have been made for motorcycles for 15+ years, and the good ones hold up to the heat just fine (much hotter environment than the 911 fan sees).

I have seen these and often wondered about them. From my experience carbon does not hold up very well to heat but most of the carbon layup I have done was wet lay and air dried. I know auto claving it and using injection molds can greatly increase its strength and heat resistance but I dont have much experience with these techniques sp I wont comment on them. My main concern would still be the balance.

Regards
Dave

[Captain Ahab Jr]

Time for some science, sorry if the following is boring but it needed saying,

Carbon fibre is inert, temperature won't damage it, the resin that holds the carbon fibre together is the part of a carbon fibre panel that isn't as tolerant to heat

With most common wet layup room temp. cured resin systems this will be very low but with a suitable resin system it can be much higher.

Every resin has a a Glass Transition Temperature or Tg for short this is a temperature where each type of resin will start to soften if taken above its Tg

There are three ways of achieving a higher Tg,

The first is chose a type resin with a higher Tg, the higher the Tg the more difficult it is to process as some of these resins turn to the viscity of water so it goes every where.

The second is to cure at an elevated temp. eg most oven and autoclaved resin systems are cured at 250ish F.

The third is to post cure the component after it has been cured and removed from the mould. The postcure temp. is higher than the curing temp. but the temp. is ramped up over time so it doesn't exceed the Tg of the resin. This prevents the component distorting due to in built thermal stresses from the cure. Tg of 480ish F is easily achievable

With the right design, materials and tooling a fan blade would be very simple part to make. I don't think balancing would be an issue as the manufacturing tolerances would be more accurate than any cast magnesium part.

[FxAffPro]

This is a very interesting read! I thought I saw that Carbon Fiber Fan Picture before here on Pelican with a brief touch on the topic, while I was looking up Fan and Shroud Restoral. So I went back digging through my notes and found this:

Page 6: Show me your...Fan!

Page 7: Show me your...Fan!

If you read through Pages 6-7 there is a brief discussion / a few posts on the topic there as well with some interesting info.

Just thought you would find it interesting. Great Thread looking forward to reading what other info comes up on the topic!

[erio]

I need to buy a fan because of a broken fan blade, and am thinking about making a form for carbon fiber fan.
There is a guy in my city that knows everything on CF, (just finished repairing a maclaren body after substential crash)
The form is going to cost about 1000 euro, and the single fan produced around 150usd material and 150 usd labour.
If i could sell 10 of them i would go ahead with the idea. We are talking about the fan without the middle steel part that will need to be reused
(if you have damaged fans, bent or with broken blades) I would love if you could send them to me for R&D)

There are some issues and questtions on the table, but we are 80% green light with making a form.

[Quicksilver]

My durability question with a carbon fan isn't heat related but instead is leading edge erosion from simple dust and crap in the air over time. It may last good for a couple thousand miles which would be excellent in a race car but on a street car I'm wondering what it would be like after 100k miles.