Aply thickness to shape string extrude

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Mongrel_Shark
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Aply thickness to shape string extrude

Postby Mongrel_Shark » Wed Oct 19, 2016 8:13 am

Not sure if this is too big an ask or if I'm just aproaching it wrong.

I would like to have extruded text protruding from a surface with a set wall thickness and a hollow inside with an open top.

The idea is to be able to fill the text with something once its 3d printed.

I have tried the thickness tool. All the faces I have tried are apparently not solid, even though they are set to solid in the shapes properties.

A also tried extruding smaller text of the same font, but the spacing between letters and the holes in the "A" for eg aslo changed. So it wont line up right. Same for bold and thin versions of the same font.

Is this possible?

I made a crude letter "O" with some circles and a square pad to illustrate what I want to do with my text. The dimensions are huge, its just an example because I wasn't sure I was explaining well.
Will I have to do that with each letter? Manually draw each one and manually draw a smaller one to pocket?
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Willem
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Re: Aply thickness to shape string extrude

Postby Willem » Wed Oct 19, 2016 10:47 am

Unfortunately i do not have time to check or my solution works. I think that Inkscape may be helpful. if you make a text in Inkscape you can grow that text so you would have than the outside and the inside thickness for your model. From inkscape you can export to freecad in DXF or SVG.
chrisb
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Re: Aply thickness to shape string extrude

Postby chrisb » Wed Oct 19, 2016 11:11 am

The following worked for me, please report if it works for you, because it does not seem to be straight forward:
  • Draft WB:
    • create Shape String
    • Downgrade, this yields a wire
  • Part WB
    • Extrude, watch out sometimes the extrude works in the wrong direction
    • Cut if necessary ( e.g. the inner of the O)
    • Thickness, watch out: by pure accident I found out, that it works with negative(!!!) thickness.
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Bildschirmfoto 2016-10-19 um 13.06.53.png
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Willem
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Re: Aply thickness to shape string extrude

Postby Willem » Wed Oct 19, 2016 1:14 pm

Hi I worked out the idea I had this morning. In Inkscape I made just an 'A', made a copy and gave it OUTSET in the PATH menu. After this I changed both text elements with the function OBJECT TO PATH and saved the drawing as a normal SVG. In Freecad I imported the SVG file in the DRAFT workbench i downgraded the 4 elements to faces, substracted the elements and extruded.
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r-frank
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Re: Aply thickness to shape string extrude

Postby r-frank » Wed Oct 19, 2016 2:01 pm

Hello.

Talking about Offset ...

DeepSOIC has added 2D-Offset-capability to FreeCAD 0.17.
If you downgrade the Draft-Shapstring-object to wires you should be able to add an Offset-Outline ...

Disadvantage of this idea (and the idea of Willem):
It does not add automatically a bottom (floor) to the letters within the cavities.
This would have to be done manually.

Roland
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Native german speaker - so apologies for my english, no offense intended :)
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Willem
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Re: Aply thickness to shape string extrude

Postby Willem » Wed Oct 19, 2016 2:46 pm

Willem @ Roland
I agree that I not make a bottom, but the Face for the bottom is already in the design. I can make it visible and if I wish I can extrude it.

Willem @ Chris
I checked your method and it works fine, I also was trying the thickness function but I did not find out about the unexpected negative value. Should this be reported as a bug? It was not a question of anybody but with playing I found out that with making FACEBINDERS, downgrading to wires, deleting the outer wire , upgrading to faces and extruding it is possible to fill the inner part, this can be very colorful
text.png
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chrisb
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Re: Aply thickness to shape string extrude

Postby chrisb » Wed Oct 19, 2016 3:21 pm

Willem wrote:I checked your method and it works fine, I also was trying the thickness function but I did not find out about the unexpected negative value. Should this be reported as a bug?
I found out by clicking a bit nervous on the down arrow of the thickness input field. And afterwards I read that depending on the sign of the thickness it can go to the outside or to the inside, so that is probably not a bug. I am not sure if the behaviour with positive thickness is a bug, people with better knowledge may judge about this. I have learned recently in the german forum that OCC might well be responsible for misbehaviour of depth.
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Willem
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Re: Aply thickness to shape string extrude

Postby Willem » Wed Oct 19, 2016 3:27 pm

With the Inkscape method it is also possible to use more than 2 of the scaled letters. Here I used an extra one for making a bottom. In the Shapestring method this is not possible
Schermafdruk van 2016-10-19 17-18-48.png
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NormandC
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Re: Aply thickness to shape string extrude

Postby NormandC » Wed Oct 19, 2016 5:05 pm

chrisb wrote: I found out by clicking a bit nervous on the down arrow of the thickness input field. And afterwards I read that depending on the sign of the thickness it can go to the outside or to the inside, so that is probably not a bug
It is not a bug. It's always been that way, and it's mentioned in the Part Thickness documentation page.

IIRC in the new PartDesignNext workbench of 0.17, the new PartDesign Thickness tool has a reverse checkbox instead. Maybe it could be added to the Part Thickness tool too.