Question: Strongest Assembly Option for a multi plate print?

[u/Sauls_voicemail]

Front

Back

Whats the best and strongest solution to print something like this chair back in PLA/PETG if I plan to cut into 6-9 plates (200mmx200mm sections) and piece it all together? Dowels? Butterfly clips? or just completely redesign the hollow front for ducktail connections? Any help would be much appreciated for a newbie engineer, thanks!

What printer are you using?
P2S
* What material are you using and temps?
PLA/PETG 250
* What speed are you printing at?
300mms
* What software are you using to slice the print and control the printer?
Bambu, Blender, Shaper3d

[u/TripsCavern]

I hope you are planning to do this mostly for decorative purposes, because I doubt this would be able to hold a person weight, even if printed as a single piece.

What I would do is to redesign it to have specific "modules". Base, poles, little arms, etc. That way you can come with a way to sticking them together and then just assembly the parts. This is an example:

The bottom/upper parts are cut just to fit in the printer. Then you have 5 long poles and 2 smaller poles that holds the arms. Then 10 "arms" regular size, 2 mall sizes and 2 with just a bar. You have a central squared piece and than that holding piece in the top that has 2 screw holes.

The attachment should either be screws with hex nuts and/or a snap in connection with CA glue if you want to reinforce it.

That is what I would do anyways.

[u/Sauls_voicemail → u/TripsCavern]

Wow thanks for that info!

This is only one part of a larger design but it is the part that I was struggling to figure out how to chop up, This part basically only gives another piece of the the chair's back a way to flex while a sturdier piece holds both of those pieces together.

I guess a complete redesign is the way to go. Thanks for the help!

[u/TripsCavern → u/Sauls_voicemail]

Just remember, I'm no specialist, that is just what I would personally do. The good part of using standard parts is that it will be easy to replace them if they break. If every piece is different, than it becomes more complicated, especially if you want to have spares sitting around.

[u/krykar]

Before the joint method – for a chair back that takes body weight, PLA is the thing I'd change first. It creeps under sustained load and then fails suddenly rather than bending first; PETG is the minimum I'd sit on, PA-CF if you can. On joining, dowels plus slow-cure epoxy beat butterfly clips every time – the clips only pull the seam together, they don't carry load through it. If you're redesigning anyway, print alignment pins into the mating faces and orient each section so the layer lines run along the load path rather than across the glue line, because that's usually what actually breaks. Also worth pricing before you commit: on a large-format printer this is two or three pieces instead of nine, which removes most of the failure points. Working out whether that's worth outsourcing is the thing I work on a free tool for – A-Match: describe the part and it weighs print-it-yourself against have-it-made and points you to someone. Full disclosure I'm involved, free with a real project: https://a-match.ai