Hexagon instead of circle

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Alexisrq
Posts: 7
Joined: Thu Dec 05, 2019 1:11 am

Hexagon instead of circle

Postby Alexisrq » Thu Dec 05, 2019 2:16 am

Hi everyone,

Let me start by thanking all the developers of this magnificent program, you guys are awesome. New to 3D drawing not new to 2D drawing. Reading the forum and watching videos I was able to draw what I need it, thanks again. Now, during the export process to cut the parts on the plasma some of the screw holes come out fine will others come out as a hexagon. This is happening on different parts and I cannot figure out why. I use sheet metal (V0.2.31) to unfold the parts, before I create the DXF I mark the unfold (not the unfold sketch) on the tree view. I have included the DXF and original drawings for reviewing. I did search the forum and could not find a solution to this, my apologies if this has been discussed before.
Attachments
Tapa motor560.dxf
(31.66 KiB) Downloaded 12 times
Tapa Frente560.dxf
(5.23 KiB) Downloaded 8 times
Tapa Motor560.FCStd
(125.73 KiB) Downloaded 13 times
Tapa Frente560.FCStd
(118.5 KiB) Downloaded 8 times
chrisb
Posts: 21384
Joined: Tue Mar 17, 2015 9:14 am

Re: Hexagon instead of circle

Postby chrisb » Thu Dec 05, 2019 9:19 am

Hi and welcome to the forum!

Please describe in more detail where we should look at. This is especially important if you upload several files!
Not being a DXF expert, it may be sensible to others to see your DXF export settings.

I have reimported the DXFs and have made the following observations:
- The sketches have "real" circles, so no issues from that side (though constraining should be improved)
- TapaFrente.dxf contains real circles, they may not look as such in FreeCAD depending on Deviation setting
- In TapaMotor.dxf the circle is made of 159 lines of 5mm length

Now some question: which dxf looks good on your machine? Did you export both in the same FreeCAD session without doing anything else? Yor files don't contain the unfolds. How did you unfold?
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Kunda1
Posts: 6427
Joined: Thu Jan 05, 2017 9:03 pm

Re: Hexagon instead of circle

Postby Kunda1 » Thu Dec 05, 2019 10:56 am

OP, welcome to the forum. Note: our guidelines request that users refrain from posting their FC info in their signatures. We ask this to specifically prevent misunderstandings since versions can change but past posts are static. Thank you.
Want to contribute back to FC? Checkout:
#lowhangingfruit | Use the Source, Luke. | How to Help FreeCAD | How to report FC bugs and features
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wandererfan
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Joined: Tue Nov 06, 2012 5:42 pm

Re: Hexagon instead of circle

Postby wandererfan » Thu Dec 05, 2019 1:10 pm

Alexisrq wrote:
Thu Dec 05, 2019 2:16 am
Now, during the export process to cut the parts on the plasma some of the screw holes come out fine will others come out as a hexagon.
If you are using the "legacy exporter" (first red box), try unsetting the "Treat ellipses and splines as polylines" (second red box).
DXFPrefs.png
DXFPrefs.png (135.94 KiB) Viewed 256 times
This gives real circles in LibreCad.
TapaMotor_legacyBody.png
TapaMotor_legacyBody.png (92.81 KiB) Viewed 256 times
Roy_043
Posts: 716
Joined: Thu Dec 27, 2018 12:28 pm

Re: Hexagon instead of circle

Postby Roy_043 » Thu Dec 05, 2019 2:10 pm

wandererfan wrote:
Thu Dec 05, 2019 1:10 pm
try unsetting the "Treat ellipses and splines as polylines"
But that is an import option.
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wandererfan
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Joined: Tue Nov 06, 2012 5:42 pm

Re: Hexagon instead of circle

Postby wandererfan » Thu Dec 05, 2019 2:48 pm

Roy_043 wrote:
Thu Dec 05, 2019 2:10 pm
But that is an import option.
It controls "DiscretizeEllipses" parameter which is used on export also.
Alexisrq
Posts: 7
Joined: Thu Dec 05, 2019 1:11 am

Re: Hexagon instead of circle

Postby Alexisrq » Thu Dec 05, 2019 3:17 pm

Let me thank everyone for the fast responses.
which dxf looks good on your machine? Did you export both in the same FreeCAD session without doing anything else? Yor files don't contain the unfolds. How did you unfold?
Yes, I did the exported all part in one session without doing anything else. For the unfold I touched the part, select the unfold item (not the unfold sketch) on the tree view and executed. After I unfold I do not save the part, I only unfold for the export. I find the unfold and the part in the same drawing a bit confusing.
OP, welcome to the forum. Note: our guidelines request that users refrain from posting their FC info in their signatures. We ask this to specifically prevent misunderstandings since versions can change but past posts are static. Thank you.
Sorry about that is been corrected.
If you are using the "legacy exporter" (first red box), try unsetting the "Treat ellipses and splines as polylines" (second red box).
I though that only applies for the import, others have confirmed that. Thanks.

I will try to be more specific. Like I mentioned before I am using the same unfold and export procedure for all parts but getting different results (that is why I suspected I did something wrong during the drawing process). On the drawings that I included Tapa Frente560 is OK I get circles when open on the plasma software, on the other hand when i opened Tapa Motor560 I get hexagons. To be honest I can edit the DXF on the CNC software StarCam, I just want to understand what I am doing wrong that causes inconstancy.

As you can see here I get circles.
TapafrenteOK.png
TapafrenteOK.png (2.12 KiB) Viewed 227 times
Here you can see the hexagons.
Tapamotor HEX.png
Tapamotor HEX.png (2.74 KiB) Viewed 227 times
Roy_043
Posts: 716
Joined: Thu Dec 27, 2018 12:28 pm

Re: Hexagon instead of circle

Postby Roy_043 » Thu Dec 05, 2019 3:28 pm

wandererfan wrote:
Thu Dec 05, 2019 2:48 pm
Roy_043 wrote:
Thu Dec 05, 2019 2:10 pm
But that is an import option.
It controls "DiscretizeEllipses" parameter which is used on export also.
Then the UI is a bit too cryptic here.
chrisb
Posts: 21384
Joined: Tue Mar 17, 2015 9:14 am

Re: Hexagon instead of circle

Postby chrisb » Thu Dec 05, 2019 6:11 pm

In TapaMotor which you uploaded I cannot see any of theses hexagons, there aren't even holes.
Alexisrq
Posts: 7
Joined: Thu Dec 05, 2019 1:11 am

Re: Hexagon instead of circle

Postby Alexisrq » Thu Dec 05, 2019 7:40 pm

Interesting, this is what I see when is open the DXF in a different program;
motordxf.png
motordxf.png (3.61 KiB) Viewed 173 times
Now, I did open the DXF on FreeCad and notice that indeed it does not have most of the holes. I did not use FreeCad before because I will not use the DXF with FreeCad. I also open the TapaFente with FreeCad and did see all the holes, that came out good when we cut it. I guess this is a starting point, if I do not see the holes in FreeCad they will not come out OK. What can be causing this problem?