Boolean text error

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Mongrel_Shark
Posts: 132
Joined: Sat Oct 15, 2016 9:54 am
Location: Australia

Boolean text error

Postby Mongrel_Shark » Tue Oct 18, 2016 3:34 am

I am attempting to make a business card for 3d printing.

I think I have successfully imported and extruded a .svg from inkscape with some text. I chose this method over scripting because scripting wouldn't let me do multiple lines of text on one face in the past. I only have one line atm but plan on adding more stuff later (Whats the best way/order to do this? I want multiple lines of text in various sizes etc and maybe some parts or cuts made in freecad if I have space, to demonstrate some of what the printer can do). Right now I am happy with one line of text, so I can test it on my 3d printer and start dialling in settings etc as its going to be a challenging print.

When I try to boolean fuse or cut the text and pad I am getting odd results on some of the letters. They are a different colour in the freecad file. I suspect this is indicating some error, but I can't work out what went wrong, or why they are a different colour. The object properties are not showing a change anywhere I have looked.

I have also found that exporting the part to a .obj is resulting in mesh errors on the black letters. I have repeated the process a couple of times from scratch. Its not always the same letters but the end result always has the same problems. Some black letters which export flaws.

I have attached a freecad file with the problem, and some screenshots of the resulting .obj in my slicing program (Slic3r) One thing I found noteworthy is that the letter "h" was separated from the object when I accidentally clicked the "split" button in Slic3r. This button is normally used when a .obj or .stl has multiple parts and you want to separate them for some reason. I don't think it should have separated the "h" as it was supposed to be fused?
Moving the h in slic3r did make it easier to see the mesh flaws though, so I took a screenshot.

No doubt I am going about this task the wrong way.
I have a few ideas on ways to try and work around this problem, but thought it would be more productive and educational to seek advice first ;)

Some things that seem fairly obvious to try are:

I think I will remove the http:// as its not really needed and then I can make the text bigger. Open to other design change suggestions.

I could probably change freecad settings to make the exported files have better resolution. The computer seems to be coping with this level of detail very well. Don't know what preferences to change though.

Maybe try doing the text in smaller chunks so it has less to compute per operation?

I'm also undecided on whether to have the words cut or extruded from the face of the card. I have a slight preference for cut into the face, but want to try both and see what prints better.


OS: Ubuntu 14.04.5 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.16.6703 (Git)
Build type: None
Branch: releases/FreeCAD-0-16
Hash: 2ce5c8d2e3020d05005ed71f710e09e9aa561f40
Python version: 2.7.6
Qt version: 4.8.6
Coin version: 4.0.0a
OCC version: 6.8.0.oce-0.17
(replaced the ubuntu freecad version on the laptop with ppa version, Thanks NormandC :mrgreen: )
Attachments
Selection_007.png
Selection_007.png (61.24 KiB) Viewed 909 times
Selection_009.png
Selection_009.png (8.14 KiB) Viewed 909 times
Selection_010.png
Selection_010.png (63.09 KiB) Viewed 909 times
mk2.fcstd
(378.4 KiB) Downloaded 12 times
mk3.obj
(147.13 KiB) Downloaded 43 times
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NormandC
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Joined: Sat Feb 06, 2010 9:52 pm
Location: Québec, Canada

Re: Boolean text error

Postby NormandC » Tue Oct 18, 2016 4:57 am

Hi,
Mongrel_Shark wrote:I chose this method over scripting because scripting wouldn't let me do multiple lines of text on one face in the past.
What's scripting? :?:

Aren't you aware of the Image Draft ShapeString tool? No need to use Inkscape for text. Plus ShapeString is parametric...

Bonus: if you click on the face of Pad when creating the ShapeString, it will be mapped to it and you'll be able to make a PartDesign Pad or a Pocket rather than a Part Extrude. No Boolean necessary! :D (you may have to rotate the ShapeString though, mine was rotated 90 degrees)
Attachments
mk2_normandc1.fcstd
(606.58 KiB) Downloaded 14 times
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NormandC
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Location: Québec, Canada

Re: Boolean text error

Postby NormandC » Tue Oct 18, 2016 5:02 am

Mongrel_Shark wrote:I chose this method over scripting because scripting wouldn't let me do multiple lines of text on one face in the past.
Not sure if you were talking about ShapeString, true it only allows a single line, but IMO it's *much* simpler to make as many ShapeStrings as you need than importing text from Inkscape and getting a gazillion faces that you need to extrude and combine...
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Mongrel_Shark
Posts: 132
Joined: Sat Oct 15, 2016 9:54 am
Location: Australia

Re: Boolean text error

Postby Mongrel_Shark » Tue Oct 18, 2016 6:23 am

Opps. I did indeed mean shape string where I wrote script.

I have had limited success with this in the past. As I mentioned. I could only get one line to boolean.

Trying to string a second line worked and I could extrude fine. But then applying that second extrude to a face that already had a cut or fusion broke my part or crashed freecad. Can't remember which. Perhaps it was just making stuff invisible before I found out about space bar. Will try that again.
I couldn't get the string to map to a face at all. Can't remember why. Will try again now.

I will also need to add a logo at some point. Its already a part in another file (.stl) So not foreseeing major problems adding it. Should I do that before or after the other text? Which order is less likely to cause problems? Thinking I will also throw in a few nut sizers or a feeler gauge/steps or something...


I see what you mean about lots of faces etc. Tried to attach the latest screw up (which is better to some extent) but the file is 2.1mb and the forum says it too big to upload.
Attached is the .obj of that file. The s and m both had issues. When cutting the s worked but the m did not. When extruding they both became cuts.

Anyway I'll try shape string again
Attachments
mk6.obj
(110.83 KiB) Downloaded 34 times
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Mongrel_Shark
Posts: 132
Joined: Sat Oct 15, 2016 9:54 am
Location: Australia

Re: Boolean text error

Postby Mongrel_Shark » Tue Oct 18, 2016 7:02 am

Ok that worked a lot better.

Although I didn't get it to map the string to the face. I had to position the string via placement property’s. Including changing the z to lift it to just below the face.. Was going to have to change that anyway and I seem to be doing it a lot quicker now. I guess practice helps a lot :D
Then I extruded. Then booleans one at a time once all the string extrudes where where I wanted.

I think last time I tried this I was extruding then moving the extrude. Which was resulting in 2 extruded parts, one where the string was and another where I placed the extrude. Somewhere through this process I was breaking something. I got very confused by the 2 copies of my extrudes at the time. Same with the .svg method I just tried.

Still can't attach fcstd file? This lime its 9mb... I put 8, 10 and 12mm hex cuts in too :) Going by how long it took to process I think I should have done part design pockets first and boolans last?

anyway my problem is all fixed. I'll upload some pics once its printed. Thanks again for the help ;) Its very appreciated. Saved me a lot of frustration and I got a better part as a result 8-)
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Mongrel_Shark
Posts: 132
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Location: Australia

Re: Boolean text error

Postby Mongrel_Shark » Tue Oct 18, 2016 11:41 pm

Just wanted to say thanks again.

This project would have taken me many days longer without help from this forum.
Last time I tried to do multiple text cuts in one face it took me a day and a half to get noting :lol:

Attached are photos of something close to the finished product. Still playing with fonts and had to make the nut holes 0.15mm bigger for a good fit.

Printed on an open source RepRap printer I made myself in Warm White ABS at 0.5mm thick in 0.1mm layers. With 0.4mm cut in one and 0.2mm extrusion in the other.

The font is not great for printing small lower case "a" or "e". Some of the finer detail is a bit rough, but overall I'm very happy
DSCN5266.resized.JPG
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DSCN5265.resized.JPG
DSCN5265.resized.JPG (312.99 KiB) Viewed 868 times
DSCN5264.resized.JPG
DSCN5264.resized.JPG (330.28 KiB) Viewed 868 times
Open Source for the win :mrgreen:
chrisb
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Joined: Tue Mar 17, 2015 9:14 am

Re: Boolean text error

Postby chrisb » Wed Oct 19, 2016 7:58 am

Thanks for sharing,it is always good to see models making it into the real world. Concerning fonts we seem to face the same problems the newspaper printers had in the old days. The Times New Roman font was used/ developed because it was able to print the small holes in the "e"s and "a"s without filling them completely with ink. Perhaps you find an old newspaper font without serifes which you can use.