Use of cyanoacrylate or other glues to assemble printed parts. Interested in comments and thoughts.
I have always endeavored to design and print my models so that they can be assembled with minimal use of external connectors or glues. However, I am beginning to take a more pragmatic approach and use superglue (cyanoacrylate) and screws when design and printing and final assembly of my model might otherwise be compromised.
Specifically regarding the use of glue, I am curious about the thoughts and experience of others on this topic? Is this the "optimal" approach? Am I using the best glue type (I print mostly using PETG filament)? How long can I expect the glue to hold under different conditions of mechanical and environmental stress? What are the alternatives?
Thanks for indulging me here.
JG
RE: Use of cyanoacrylate or other glues to assemble printed parts. Interested in comments and thoughts.
I can tell you how long the glued parts will hold, this also depends a lot on the contact area and stress scenarios. Cyanoacrylate glues are however in my opinion among the best allrounder glues for plastics in general. Your glueing strength might be enhanced by roughening up the contact surface with fine sanding paper first, and/or using activator.
For long lasting connections, especially under mechanical stress screeing connections, either with screw and nut or with screw and heat insert will be probably the better choice
Mk3s MMU2s, Voron 0.1, Voron 2.4
RE: Use of cyanoacrylate or other glues to assemble printed parts. Interested in comments and thoughts.
PS: PETG itself isn't the best material for glueing, if not to say among the worst. ASA/ABS for example aren't as tricky. Nonetheless cyanoacrylate glues work also with PETG, but probably less effective than with other polymers.
Mk3s MMU2s, Voron 0.1, Voron 2.4
RE: Use of cyanoacrylate or other glues to assemble printed parts. Interested in comments and thoughts.
I found CA glue to be an excellent tool, especially with PETG. Blow on one of the surfaces so the moisture of your breath will accelerate the bonding process. I found that my models are more likely to break elsewhere than at the glue site. I use brass heat inserts and screws or bolts and nuts as well but frankly only when I need to be able to separate the parts again.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Use of cyanoacrylate or other glues to assemble printed parts. Interested in comments and thoughts.
I often use CA for all kinds of plastics and had no problems so far. At least not if I remember to clamp the parts together while the glue is setting in order to ensure a tight fit.
There have been a few situations where CA wasn't enough - for example that one time I had to glue a PETG part to a part made of HDPE... For those situations, I always have some epoxy in storage. 🙂
RE: Use of cyanoacrylate or other glues to assemble printed parts. Interested in comments and thoughts.
I like Starbond KEG-500. It's a flexible superglue. It's fast, effective, and won't crack or craze like regular superglue does.
As for fasteners, I like M4 machine screws for attaching parts together. They're self-threading and are quite strong. I also use pegs, slots, anchors, and lots of surface area with right angles to attach multiple parts together.
RE: Use of cyanoacrylate or other glues to assemble printed parts. Interested in comments and thoughts.
I too have had very good success with CA for PETG parts. I also use CA when attaching parts to metal though it is important to make sure you have a good fit before gluing up. Clamping is also a good idea.
RE: Use of cyanoacrylate or other glues to assemble printed parts. Interested in comments and thoughts.
CA may be sometimes tricky because it may bond too quickly.
So I prefer two part epoxy that bonds in 10 about minutes.
See my GitHub and printables.com for some 3d stuff that you may like.
RE: Use of cyanoacrylate or other glues to assemble printed parts. Interested in comments and thoughts.
Despite this thread being old - I hope this of help to people. little talked about / an under appreciated fixing type are screws designed to be “thread forming” (that’s a technical term) into pilot drilled plastics . Often called “PT” screws if you search Ali express - one branded type are “plastite”. I think the early patents must have expired as they are available as generics off Ali express cheap as chips.
they are astounding - don’t be fooled. They are NOT self tappers - (they are designed to minimise hoop stresses unlike self tappers which tend to split plastic) and have a chunky enough thread the pull out force is extremely high, unlike trying to mash a machine screw into a hole - which never works well.
the best bit is - once you’ve gone in with them, my experience is you can take them out put them in take them out etc dozens possibly hundreds of times into the same hole - they somehow don’t mash the plastic up. All these heat insert brass things like Stefan of cnc kitchen goes on about are old, silly technology. Pt screws are so cheap just get some - don’t pick about with screws that aren’t designed for the job you have.
I found out about these when iterating a design for manufacture and agonised over helicoil inserts, heat inserts, putting nuts in pockets etc and concluded all of those are way Infererior ways of proceeding prone to problems time consuming, high error rates costly etc.
RE: Use of cyanoacrylate or other glues to assemble printed parts. Interested in comments and thoughts.
What I was hoping for was if anyone has experimented with slots for CA glue - where one uses surface tension to wet out a slot with the liquid - esp runny CA - between two (small) components and if anyone has any observations having done this ? This seems a more sophisticated way of proceeding than relying on sloppy tolerances and sobbing on the glue and clamping. Slant 3d on YouTube has a couple of videos about glue slots which are through provoking but it quite what I’m looking for for very small parts, to save me having to do lots of experimentation !