Lets talk Glue

#1

Im printing a tank, and needed to glue flexpla to regular pla for the profiles on this track:

http://i.imgur.com/S6zXWC9l.jpg

I tried CA glue and epoxy, and found both really bad. UHU Por was a little better, but still not good. I googled and found this test of glues for 3D printed PLA:

Really useful info. So I bought the by far best glue in that test, loctite gel control. Cost me €8 for a bottle.

http://i.imgur.com/bk67X5Xm.jpg

I bought two, just in case. After gluing 3 or 4 profiles, I couldnt believe it, but the bottle seemed empty! I thought I had a dud bottle, used the second one, same thing. Then I read the small print: it contains 3 gram of glue.

http://i.imgur.com/f6aKKM1m.jpg

3gr in a (opaque!) bottle which can hold 30 I think. And of which, you probably can only get 2gr out. Thats a few drops! What a ripoff.

I ended up using this Bison “hard plastic glue”:

Which worked almost as well, and costs just a tiny fraction. I completed all 84 tracks and the tube still looks full.

I would love if Tom made en episode on glueing 3D printed parts in various materials.

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#2

Take some scrap abs, mix it with acetone and leave it over night. It works like magic on almost all 3d prints

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#3

This could be a bit late for your job but it is allways an option to redesign the part with some sort of mechanical interlock.

Consider the dovetail joint that was used in furniture making if you look at the design of the Original Iron Bridge (the first in the world) you will see that it has cast dovetail joint’s admitedly they are held in place with nuts and bolts and the cabinet maker joints were also supported with the glues of their day.

They did not have the mass production manufacturing tollerances we have today.

Note that even older constructions worked with peg and dowl constructions that used no glue.

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#4

Dovetails would be nice, but in this case, unfeasible and virtually unprintable:

The top of the track pieces are the bottom of the print, because the other side has spikes to grip the drive wheels.

And I really dont want to remove support material from almost 100 pieces!
Regardless, sometimes you just need to use glue, particularly if you want to print without using too much support material, and knowing which glues work on what materials would be interesting to many.

(And yes, I printed several sets in several materials/colors to find what works. The tank is powered by 2 motors that are WAY too powerfull, I can do front and backflips at 30% throttle, and they pulled apart ABS chains with ease. PETG faired no better. PLA was considerably stronger in tensile strength, but I ended up using semiflex PLA which proved by far the strongest of my materials for this application. I even reprinted my frame in semiflex, because once my chains held up, I started breaking my PETG frame!)

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#5

I don’t have anything to add in glue departament but thats pretty nice printed model! Really nice :smiley:

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#6

Yes, glues is a complete subject on its own.
I think there are some flexible glues too, that would be nice in such a situation.
Other option I see a lot is plastic welding, using a soldering iron or even better a 3d printing pen.

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#7

Wow! Which printer did you use?

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