Poor layer bonding as a feature

[tray]

Anybody ever taken advantage of poor layer bonding?

For example, print a shape with poor layer bonding to use as mandrel for laying up a carbon fiber/epoxy composite, and then unravel the mandrel from inside? Tricky bit I suppose is to tailor the bonding to be just strong enough.  

Should work for casting operations too.

ABS and silk PLA seem likely candidates.

[Ryan Carlyle]

Hmm. Does seem like it ought to work. Maybe setting up a slicer profile to under-extrude or drop temp for a few layers would work?

[Daren Schwenke]

I have done this with Nylon, mostly by accident as I was still figuring it out at the time.

The layer bonding between my first two layers was terrible as my bed and print temperature was too cool, but the first layer peeled away from the second very nicely.  The rest of the layers were fine.

Later I used this 'feature' by printing a completely solid first layer, and then I started my through holes and such at the second layer.  They turned out much better than trying to start them on the bed.

I do a similar thing when I need a bridge with a hole in the center.  I model one layer as solid and start the hole above that.  They turn out much better.