Best way to model mitre fold?

[ssashton]

Hi everyone,

I want to model an assembled box that will be 3D printed as a flat part and folded along mitre lines to form the shape.

I was thinking this would be easy in sheet metal (I've not used much) but looks like it's only for bending uniform material.

What do you think is the best way to model a mitre fold box?

Thanks!

[TheCADWhisperer]

@ssashton Model in finished form as best you can and then Attach your file here.

(Use any tools  you know.)  (Attach images if you have seen something similar in the real world.)

Someone will then show you how to achieve Flat Pattern.

[ssashton]

I have made this example with a 'traditionally' model mitre box where each wall is a separate body and I used the chamfer tool to add the mitre. Doing it this way obviously needs me to think much more about the joints than if Fusion just added them in as needed.

Next to it is a sheet metal box that I thought would be able to produce the same result with mitres instead of bends and large gaps. But I don't know how to make it do what I need.

https://a360.co/2XPf6jW

[TheCADWhisperer]

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

[ssashton]

Here

[TheCADWhisperer]

Are you trying to do something like this?

[ssashton]

Yes! Only I imagine this would work better for folding plastic.

[TheCADWhisperer]

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@ssashton wrote:

 Only I imagine this would work better for folding plastic.

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You completely lost me here.

I thought you were 3D printing this in flexible plastic?

[ssashton]

That's the plan. I don't believe the straight edged groove you show along the fold line is nessicary, just the mitre and a small flat area that will become the bend / fold radius. If those properties can be set in sheet metal mode it would be quite easy to design I think.

[TheCADWhisperer]

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@ssashton wrote:

If those properties can be set in sheet metal mode it would be quite easy to design I think.

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Nope.

You will have to model flat.

[HughesTooling · Accepted solution]

Might be worth experimenting with a thin sheet metal part like this, need to experiment with the bend radius.

Then flat pattern and extrude the flats and chamfer.

Then refold. Might work might not but you can always print a small test part and see how it goes. See attached file.

[ssashton]

Thanks! I think that gets me 80% where I want to be 🙂

FWIW I did a test print from a model I made as separate bodies and joined. Seems like I under-estimated the needed bend radius, but otherwise it works well.  The piece is 1.5mm thick with a 0.2mm bottom layer that ties it all together. The gap between the sections was also 0.2mm but like I said it's not enough.

The reason I want to print like this is because it gives me a very smooth texture (from the print surface) on all showing external surfaces. If I were to print it as a 3D part in the normal way I would have layer lines on the outside walls. I can paint this more easily, use decorative print patterns or even use a print surface with a pattern on it like these hologram ones.

https://makezine.com/2020/02/18/this-clever-trick-embeds-holographic-patterns-in-your-3d-prints/