Beginnings of an Easter Egg

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abasel
Posts: 67
Joined: Sun Sep 02, 2018 12:22 am

Beginnings of an Easter Egg

Postby abasel » Sat Apr 11, 2020 2:27 am

The idea here is to 3D Print some eegs that can hold differet sweets or toys. Once I know that the base prints fine I will look at decorating and theming them. This is the fist model I have completed that appears to have (more or less followed) recommended approaches. I.e. when I went back and made some changes higher up it did not appear to break the egg. Anyway I am sure that there is lots of room for improvement but here goes :)
FinalEgg.PNG
FinalEgg.PNG (171.62 KiB) Viewed 872 times
The egg shape I constructed using the following guidelines http://www.gogeometry.com/geogebra/eucl ... ablet.html.

My approach was as follows:
  • Create two eggs, one 10mm shorter than the other and then use the smaller one to hollow out the larger one
  • Use "Split Apart" to break the egg in half
  • Use group to cut the interlocking join
Now I just need to wait for the lockdown to end so that I can access some 3D printers :D

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OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.16131 (Git)
Build type: Release
Branch: releases/FreeCAD-0-18
Hash: 3129ae4296e40ed20e7b3d460b86e6969acbe1c3
Python version: 3.6.6
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/NewZealand (en_NZ)
Attachments
EasterEgg.FCStd
(160.02 KiB) Downloaded 5 times
kisolre
Posts: 2102
Joined: Wed Nov 21, 2018 1:13 pm

Re: Beginnings of an Easter Egg

Postby kisolre » Sat Apr 11, 2020 7:51 am

Nice :)

But... When you design for a real world you should consider the manufacturing process, tolerances, ease of production, ... For 3D printing you should really consider overhangs, print orientation, bridging, ... Here is a design based on your main shape sketch - good work there :) Designed to be printed on the circular edges (bottom part should be printed upside down), 0.4mm nozzle, 0.56mm default external perimeter, with brim for adhesion. Note the flat spots inside - those will be bridged - might look a look a little ugly on the inside but will not need supports.
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EasterEgg_kiss.JPG
EasterEgg_kiss.JPG (121.2 KiB) Viewed 834 times
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For the snap note the 45 deg overhangs and the clearance between vertical parts to ensure they will fit together. This can be easily adjusted (the 1.9mm dimension - 4mm-2*1.9mm=0.2mm clearance). If it is too loose or tight.
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EasterEgg_kiss_snap.JPG
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EasterEgg_snap.JPG
EasterEgg_snap.JPG (19.67 KiB) Viewed 834 times
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I used Body BaseFeature to link the geometry of TopPart and BottomPart to the FullEgg and cut what is not needed. Then used Sketcher CarbonCopy to copy geometry from the base shape sketch to TopPart and create the cut profile based on that. Same for BottomPart but copied from Top part to create matching geometry.
Use "Hidden lines" view mode (default is "As is") to preview the generated mesh and adjust Angular deflection and Deviation to get finer mesh for export.
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EasterEgg_kiss_FineMesh.JPG
EasterEgg_kiss_FineMesh.JPG (238.03 KiB) Viewed 834 times
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Now I should print one to see if all advice holds true :D
Attachments
EasterEgg_kiss.FCStd
(45.4 KiB) Downloaded 16 times
kisolre
Posts: 2102
Joined: Wed Nov 21, 2018 1:13 pm

Re: Beginnings of an Easter Egg

Postby kisolre » Sat Apr 11, 2020 9:36 am

So far so good:
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Attachments
20200411_123111.jpg
20200411_123111.jpg (994.41 KiB) Viewed 809 times
abasel
Posts: 67
Joined: Sun Sep 02, 2018 12:22 am

Re: Beginnings of an Easter Egg

Postby abasel » Sat Apr 11, 2020 9:51 am

Thanks Kisolre, you taught me heaps :) A much simplier approach.

Just some questions
  • What is angular deflections
  • What is deviation; and what am I looking for when using this and the above
  • When I use hidden lines, my view is not a clear as yours; is there some setting I need to tweak?
  • When you say the flat inside part will be bridged and not need supports, what do you mean?
HiddenLines.PNG
HiddenLines.PNG (158.82 KiB) Viewed 803 times

There is a book on Amazon that I have been looking at on FreeCAD - would make it much easier than having to Google and ask when I try these sort of things; I think I might give that a go.

Thanks for your help :D
kisolre
Posts: 2102
Joined: Wed Nov 21, 2018 1:13 pm

Re: Beginnings of an Easter Egg

Postby kisolre » Sat Apr 11, 2020 11:11 am

3D printing Bridging https://all3dp.com/2/bridging-3d-printi ... t-bridges/
3D printing supports https://all3dp.com/1/3d-printing-support-structures/
3D printing Bed adhesion (Brim) https://all3dp.com/2/3d-printer-bed-adh ... d-to-know/
PartDesign_Preferences - check Shape view section and Expand description there for in depth description of Angular deflection and Deviation.

For the View port rendering there are some settings under Edit/Preference/Display. You could try play with them and see if that helps.
kisolre
Posts: 2102
Joined: Wed Nov 21, 2018 1:13 pm

Re: Beginnings of an Easter Egg

Postby kisolre » Sat Apr 11, 2020 5:00 pm

And here is the result. Sorry for the bad lighting.
Bottom part. Note the bridging. Not so bad.
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20200411_163252.jpg
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20200411_163245.jpg
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Some spliced filaments from the end of spools for the Top part.
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20200411_193819.jpg
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20200411_193923.jpg
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0.2mm clearance was too much and the fitting was quite loose. Nothing a little heating with a lighter cant solve :)
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20200411_194200.jpg
20200411_194200.jpg (983.58 KiB) Viewed 734 times
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Thanks for the inspiration :D
abasel
Posts: 67
Joined: Sun Sep 02, 2018 12:22 am

Re: Beginnings of an Easter Egg

Postby abasel » Thu May 07, 2020 10:36 am

When I originally worked through this I was able to do each step. On going back to in now I cannot work out how the carbon copy works. In the attached file you will see that I have created "MyPart" and I have got the base feature that links to the FullEgg but I can no longer work out how to copy the geometry from the FullEgg to MyPart. I did try creating a sketch under MyPart but did not seem able to copy the geometry to it. https://wiki.freecadweb.org/Sketcher%20CarbonCopy has not made things any clearer for me.
Attachments
EasterEgg_kiss-AB.FCStd
(42.8 KiB) Downloaded 2 times
abasel
Posts: 67
Joined: Sun Sep 02, 2018 12:22 am

Re: Beginnings of an Easter Egg

Postby abasel » Thu May 07, 2020 10:48 am

Ok I worked it out; I will document here in case someone else has trouble :)

1) Create a new sketch.
2) While in edit mode of the above, go to the model navigation and make sure the sketch that you want to copy is visible.
3) Use the CarbonCopyTool to copy the geometry.

Another thing worth noting is not to delete any of the copied geometry. If any is not needed then convert those lines to construction line.
kisolre
Posts: 2102
Joined: Wed Nov 21, 2018 1:13 pm

Re: Beginnings of an Easter Egg

Postby kisolre » Thu May 07, 2020 11:21 am

abasel wrote:
Thu May 07, 2020 10:48 am
Another thing worth noting is not to delete any of the copied geometry. If any is not needed then convert those lines to construction line.
Yes and no. If you only need some of the geometry from the copied sketch you can think how to reduce what remains as long as it serves the purpose for which carbon copy was used. The more important thing is that you should really be done with the copied sketch and not modify its shape, number of edges, the way it is constrained later because this will not propagate in to the copy and 99% of the time things will brake in an non obvious way which will be hard to fix.