Though I’ve done this in the past, I’ve never had the best results with it. Any other materials besides hot-glue? I’m sure smooth-on has a product that’s pretty thick (to prevent leakage) and could be just as easily injected.
Originally shared by Michael Ball
http://www.fabbaloo.com/blog/2014/4/18/how-to-make-any-3d-printed-part-much-stronger#.VNPQpWeooUg.google_plusone_share
An interesting approach.
I suspect the ticket here is to design the part with cavities with the intention of injecting the hot glue or some sort of epoxy. Like a low infill of honeycomb maybe?
Ive been doing that for parts for a while. I posted a howto on that about more than year ago. I print parts with 0 infill and wanted to embed a bolt. Superglue the bolt in where you want it and while adding hot glue add more superglue carefull hot supergue vapour is nasty cover your eyes mouth etc. I actually saw the part the other day its still rock solid.
Fill a syringe with steel-filled epoxy and inject it. I thought this might be a good approach the moment I saw the porosity of 20% infill. You must use a porous infill so honeycomb, for instance, will not work.
The problem with infill if you go the route of drilling 2 holes. is that it generates an internal structure sealing compartments. you would need to drill a hole over every cavity to fill it. maybe if your slicer did a random infill that resembled fiberglass strands then epoxy would be a killer addition.
I’ve never gotten really good adhesion with hot glue, but it could be fine in compression. As for porosity, shouldn’t the “every N layers” setting with a really large N work?
@Michael_Scholtz , rectilinear infill seems to be fully porous in Slic3r.
A project by the Arizona State University studied the increase in strength of 3D printed plastics by annealing them at 140 degrees Celsius, among other things.
https://drive.google.com/file/d/0B9SJV8KxtGNQWHVBc2FkTVZubFU/edit
Their conclusion was that an anneal temperature of 140 degrees Celsius for 1/2 an hour increased the mechanical stiffness - thus making it harder to fracture under stress.
There is a warning that the annealing may warp the parts, and I am just guessing that uncontrolled cooling may be the cause of that.
The theory seems to be, that like metallurgical annealing, the structure of the part is relived of internal stresses, and also the layers bond together better.
The study seemed a bit light on detail to me, and I am hoping for a more thorough investigation of annealing by someone, or some group.
But at least this type of process is easily achievable by the home hobbyist, say in a normal oven, and has the immediate benefit of greater strength.
@paul_wallich I used Superglue to aid adhesion between the glue and the plastic. (and again heated superglue fumes are nasty!!)
@Michael_Scholtz
Eek. I’ve infused parts with superglue, which gives you the tensile strength, and that was bad enough.