[Timmmmbob]

> The strongest CF pieces are made of unidirectional CF, where all fibers are oriented in the direction of the main effort.

You're confusing issues even further! To anyone who wants to actually understand this:

Carbon fibre doesn't have a single "strength" value since it is virtually always anisotropic - its strength varies massively depending on which direction you stress it in.

GP is correct in that the carbon fibre weave with the best minimum strength is the 3D woven stuff which is very fancy and difficult to make, and not what this printer makes.

The most common carbon fibre is 2D woven cloth which is laminated together like plywood. It is strong in the directions of the fibres but can very easily delaminate (the layers become unstuck). It's a pretty big problem for things like the Boeing Dreamliner because the delaminations can be under the surface and impossible to see.

CFRP tubes are often made with the fibres all running along the axis of the tube, but it is then extremely weak in the circumferential direction and will tend to split like bamboo.

[marvin]

Delaminated Dreamliner sounds like a maintenance person's worst nightmare. Wouldn't you have to replace the entire part? Where "part" is wing, rudder or fuselage.

[a-priori]

Replacing a defective part is no big deal, just incorporate an inspection of the part into a regular maintenance window every X cycles (a 'cycle' is usually one flight) and model its cost as an amortized per-cycle cost based on its mean time to failure.

The problem is when it's difficult to know whether a part is defective. Something like subsurface delamination might cause visible bubbling or warping, but if it's deep enough then it may only be apparent on an ultrasound or X-ray scan. That sort of scan might be more expensive than just replacing the part regularly, and shipping it off to a factory to be inspected and refurbished.

That is a maintenance technician's worst nightmare: an expensive and bulky part that fails in invisible ways, requiring either regular replacement or time-consuming inspection with expensive equipment.

[na85]

Delaminated Dreamliner sounds like a Fedora or Ubuntu release codename.