How do you guys tackle replica vs functionality for 3D printing?

tim.lavelle · ‎08-31-2022

Hey All - So a question for those of you who replicate props for 3D printing....

I'm a huge Stargate fan, and I created a replica from a high detail image for the original Milky Way gate and I am REALLY happy with all my details, parts, keys, etc....

I started test printing and found out that even at 20cm in diameter, some parts are too small for mechanics/LED lights and it's pretty disheartening. Obviously in Fusion, details are amazing and look great, so I wanted to ask the forum what some of you do to find the right balance between replica modelling, and functional design?

The piece which I'm quote troubled about is what the movie calls 'Chevron Locks' which light up and move and I modelled it in Fusion with the intention to add Neopixel LEDs, but when I printed them... they're just too small for any kind light, even though the pieces are properly scaled.

Here's a few photos of my model, and the a photo of the pieces which were intended for LEDs and movement...

Just looking for a bit of guidance on what best practice might be!

Thanks all!!

Warmingup1953 · ‎08-31-2022

Perhaps fibre optics? https://youtu.be/7lLvbqQnIuY?t=35

TrippyLighting · ‎08-31-2022

My "best practice" is to model everything that goes into the full product. In this case that would include the electronics and the LED strips or individual LED's.

This does not necessarily need to be super detailed, but just the main dimensions and geometry, so you can see things together in context.

GRSnyder · ‎08-31-2022

I'm a little unclear about exactly what you're asking (general design approach? mounting LEDs? how to determine an appropriate level of detail?), but I like the project!

It looks like you have enough thickness to accommodate Neopixels. You just need to recess them into the body, separate them into opaque cells (to avoid light bleed), and add white or transparent diffuser windows to let the light out. It doesn't matter if the actual LEDs are a centimeter or two away from where "the lights" are on the surface of the piece.

As @TrippyLighting said, you do need to design all this stuff (Neopixel holders, diffusers, chambers, wiring channels, etc.). But it's not a bad approach to start with what you want the model to actually look like and work forwards from that. The main issue is going to be that as the internal structure gets more complicated, you have to think more carefully about how you're going to manufacture everything. What parts are separate? What needs to be printed in multiple sections and glued together?

To move the chevrons, you can probably use a single circular camshaft that's controlled by one motor or servo in a base unit. Spring-load the chevrons so they're closed unless actively pushed open (more stuff to design!), then have the cams push them out. If you want to get fancy, you can create sequential motion without adding any additional complexity by designing the cams properly.

Some good references:

Take a look at the Voron Stealthburner design, especially the front plate (the "Stealthburner" proper). There are some nice Neopixel holders in there, including a central one which is recessed into the body and has a diffuser.

The book Making Things Move is a good, nontechnical reference for basic motion systems.

tim.lavelle · ‎09-01-2022

Yeah, good point @TrippyLighting, not sure why I didn't start with that and I just assumed it would be big enough... Lesson learned!

And great advice @GRSnyder, really appreciate it! I should have started with knowing what I wanted to put in (electronics wise) and will do that from now on and great recommendation with the book! I've just ordered it from the amazon AU site!