I want to print a model of an animal cell.
What I have so far: I managed to use different colors to print out the different parts of the cell.
My question is: what is the best way to connect plastic 3d printed parts?
Glue? Melted plastic? I need it to have a strong connection and not very visible when used well, and preferable dries fast.
For ABS print, I recommend acetone. It is not a glue, but it will dissolve the plastic a bit and if you apply it to both connecting parts and push them together, they will stay connected after the acetone dries. However, it does not dry very fast and you have to be careful not to destroy the object.
For PLA I usually use regular super glue (Cyanoacrylate).
For ABS I use a gel super glue (Loctite is my current favorite), it seems to slightly melt the ABS parts together and makes for a great bond. A slurry of old scrap ABS and acetone also works well, though I find that it will evaporate even if left in a closed mason jar over time. The small nozzle applicator and the fact it doesn't seem to evaporate makes super glue the better choice for me.
The gel super glue works "OK" for PLA but I've had parts fail after taking a small tumble. I just started using this acrylic cement for PLA. It cures very fast but seems to slightly melt the PLA in the same way the ABS options do.
For internal seams I like to put a bead of "high performance" hot glue over the seam. It's just a bit flexible and seems to do a good job taking drops.
Lastly I really like (but haven't mastered) friction welding parts together using a Dremel. Matt Griffin at MAKE Magazine did a great write up on the technique here.
After doing the processes that hroncok described, the edges of the print can be finished with a 3D printing pen. The pen extrudes filament as a regular print head does, but is hand held. The filament can be extruded on the previous gap between the two prints. It will melt between the two sides and can be finished to create a smooth connection point.
