letters disappearing

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pmonro
Posts: 11
Joined: Wed Oct 14, 2015 2:46 am

letters disappearing

Post by pmonro »

I am trying to print letters on 3d printing. I created the letters in inkscape and then extruded them with "part"
Everything looks good and I created the stl file for printing. Sadly when I reload the stl file the letters have disappeared.
Help please?
Fcstd is attached

OS: Windows XP
Word size of OS: 32-bit
Word size of FreeCAD: 32-bit
Version: 0.15.4671 (Git)
Branch: releases/FreeCAD-0-15
Hash: 244b3aef360841646cbfe80a1b225c8b39c8380c
Python version: 2.7.8
Qt version: 4.8.6
Coin version: 4.0.0a
OCC version: 6.8.0.oce-0.17
Attachments
fencelid.FCStd
(282.59 KiB) Downloaded 19 times
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DeepSOIC
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Location: used to be Saint-Petersburg, Russia

Re: letters disappearing

Post by DeepSOIC »

Hi!
You seem to have messed up all the extrusion.
Your letters are extruded twice. First extrusion makes a shell, second extrusion in the same direction makes them invalid compsolids.
What you need to do is to extrude each letter once, with 'make solid' set to true. And cut out the missing holes, with Part Cut.

Why aren't you using Draft ShapeString?
pmonro
Posts: 11
Joined: Wed Oct 14, 2015 2:46 am

Re: letters disappearing

Post by pmonro »

Ok thanks for the advice. I will also try shapestring.
Thanks again
pmonro
Posts: 11
Joined: Wed Oct 14, 2015 2:46 am

Re: letters disappearing

Post by pmonro »

Any more ideas?
New file attached. I carefully extruded the letters and even tried a single letter but they still disappear when the stl file is reloaded.
I can not get shapestring or text to work. I have freecad version 15. The tutorial says I need version 16
Attachments
fencelid.FCStd
(74.41 KiB) Downloaded 25 times
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DeepSOIC
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Re: letters disappearing

Post by DeepSOIC »

What are you exporting? Exported is what is selected.
Additionally, the self-intersecting mesh you are going to get if exporting plate and letters being separate objects, may confuse the slicer. Or whatever else you are about to use the mesh for. So Part Fuse the letters to the plate (Part Fuse accepts multiple selection btw, and extrude does too IIRC). Then export just the fusion.
pmonro
Posts: 11
Joined: Wed Oct 14, 2015 2:46 am

Re: letters disappearing

Post by pmonro »

Thanks for your interest deepSOIC
I am exporting what I select in treeview. I can reload the stl file with the base or the letters but not both.
I note your suggestion I use part fuse but my version 15 does not have this facility. Perhaps I have not downloaded the complete version. The manual just says 'Fuse" is in part complete.
Have you exported my file on your build and will the stl file return with the letters?
Thankyou
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bejant
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Re: letters disappearing

Post by bejant »

Hi pmonro, the second file you posted is still messed up.

Firstly, the path of the r in "Electric" (Path3358) intersects itself here (which is no good and is why the r can't be Extruded into a solid):
20151120b.png
20151120b.png (1.77 KiB) Viewed 1401 times
If you zoom way in it looks like this:
20151120a.png
20151120a.png (1.98 KiB) Viewed 1401 times
The green line segment is only about 17 nm in length.

Instead of trying to fix it I just used the Draft WB > Bspline (no, it was Dwire) tool and traced over the Path, then Extruded it to create a Solid (Extrude018).


Also, the enclosed area inside the top of each lowercase e is an Extrude and so fills in the the letter e, which is probably not what you want.
Select Extrude002 and subtract Extrude003 from it using the Part WB > Cut tool. This creates "Cut".
Do the same for Extrude011 and Extrude012 to create "Cut001.
Repeat for Extrude015 and Extrude016 to create Cut002.

Now I'd select each of the Extrudes (except Extrude006 which is the botched r) and all three Cuts, then do a Part WB > Boolean Union to create Fusion as was done here:
20151120b-fencelid.FCStd
(693.31 KiB) Downloaded 18 times
Now select only Fusion in the hierarchy tree and export it as a .stl.

P.S.: The area of the text "Electric Fence" is only about 40 mm wide x 37 mm high, is that what you want? If not, you can make a copy of Fusion and resize the copy before exporting.
Last edited by bejant on Sat Nov 21, 2015 3:20 pm, edited 1 time in total.
pmonro
Posts: 11
Joined: Wed Oct 14, 2015 2:46 am

Re: letters disappearing

Post by pmonro »

Thanks bejant
Your diagnostic process is new to me, and a big jump up my learning curve. I will definitely give it a go. Thankyou
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bejant
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Re: letters disappearing

Post by bejant »

pmonro wrote:Thanks bejant
You're welcome. I should have also written that at first I thought that Extrude006 (the r) didn't have the Data tab (bottom of the Combo View window) > Solid property toggled to True, but then saw that it was set to true and from there it was a matter of trying to figure out why Extrude006 wasn't a solid. Often two segments have a tiny gap between them (which causes problems when trying to create a solid), so that's what I was looking for when I found the crossed line segments instead.
pmonro
Posts: 11
Joined: Wed Oct 14, 2015 2:46 am

Re: letters disappearing

Post by pmonro »

Thanks again bejant
I started with correcting the letter "R in the svg file from inkscape
Then extrude, part boolean cut the letters"E and part boolean union the letters and base and then export to create the stl file.
It all worked well.
I tried to attach the fcstd file to this post but to my surprise it was 1.4Mb and was not allowed.
I also tried to resize the base but could not find how to do it. I eventually redrew it in the svg file. Am i missing something here.
Thankyou
Peter
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