Most efficient way of importing a dxf to a sketch

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geobruce
Posts: 48
Joined: Sat May 19, 2018 9:34 am

Most efficient way of importing a dxf to a sketch

Postby geobruce » Mon Aug 26, 2019 8:40 pm

Hi

I'm trying to import a dxf (from librecad) into freecad. I would like to have one sketch with all the hexagons so I could pad this sketch on top of a circular base.

What would be the best or easiest way to do this?
At the moment I can:
- select all parts of one hexagon
- upgrade (draft)
- convert to sketch
But this can't be the right way to do it.

Thanks in advance!
Attachments
Screenshot from 2019-08-26 22-37-42.png
Screenshot from 2019-08-26 22-37-42.png (175.88 KiB) Viewed 544 times
only hex.dxf
(520.94 KiB) Downloaded 15 times
hex grid only.dxf
(521.07 KiB) Downloaded 16 times
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bejant
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Re: Most efficient way of importing a dxf to a sketch

Postby bejant » Mon Aug 26, 2019 10:12 pm

geobruce wrote:
Mon Aug 26, 2019 8:40 pm
I'm trying to import a dxf (from librecad) into freecad. I would like to have one sketch with all the hexagons so I could pad this sketch on top of a circular base.
To me it looks like you only need one Sketch of the circular base, and another Sketch of one hexagon. I wouldn't make a Sketch that contains every hexagon, mainly because Sketcher Solver would take a prohibitively long time to solve such a Sketch. My suggestion id that you Pad your circular base, then Pad one hexagon (probably the center one) on top of the base, then use either Part Design WB > PolarPattern or MultiTransform to make the remaining hexagon solids.

Or you could use Part WB > Extrude to make an Extrude of one hexagon, then use Draft WB > Array to make the copies.

Either way, with that many objects in your model, FreeCAD will slow down significantly.
chrisb
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Re: Most efficient way of importing a dxf to a sketch

Postby chrisb » Mon Aug 26, 2019 10:30 pm

For such a number of objects I would recommend Draft->Array, as (sad to say) the PartDesign patterns are by far not as efficient as their draft counterpart.
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TheMarkster
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Re: Most efficient way of importing a dxf to a sketch

Postby TheMarkster » Mon Aug 26, 2019 10:39 pm

Take a look at FCHoneycombMaker macro.
My FreeCAD video series on youtube: https://www.youtube.com/c/mwganson
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bejant
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Re: Most efficient way of importing a dxf to a sketch

Postby bejant » Mon Aug 26, 2019 10:49 pm

...which reminds me that there are a few forum topics about making a honeycomb pattern, and also that DeepSOIC used his Lattice WB to do that too.
geobruce
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Re: Most efficient way of importing a dxf to a sketch

Postby geobruce » Tue Aug 27, 2019 8:07 am

bejant wrote:
Mon Aug 26, 2019 10:12 pm
Either way, with that many objects in your model, FreeCAD will slow down significantly.
What other tool/software would you recommend to generate the desired shape? openSCAD maybe?
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bejant
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Re: Most efficient way of importing a dxf to a sketch

Postby bejant » Tue Aug 27, 2019 4:46 pm

I haven't had a need to use any other 3D CAD programs in the past several years, but I think it would probably be faster to create your model in FreeCAD than it would be to search for and then learn some other software.

Simply eliminating the rounded corners from the hexagons would probably speed processing time up a bit.
TheMarkster
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Re: Most efficient way of importing a dxf to a sketch

Postby TheMarkster » Tue Aug 27, 2019 7:57 pm

phpBB [video]

honeycomb_circle.FCStd
(612.52 KiB) Downloaded 12 times
These hexagons don't have the rounded corners. If you want that you might be able to replace the HoneycombHexagon object as the base of ExtrudedHexagon with one of the rounded hexagons. I would see if I could select all the edges and make a compound, then extrude the compound (this would be extruding a single rounded hexagon). Then make that extruded rounded hexagon the base for the 2 draft arrays --HoneycombArray1 and HoneycombArray2.

Using compound explode on the Fused_Arrays object is the key to being able to individually delete the extruded honeycombs from the array to get the diamond shape. If you change the size of the array you will have to probably explode that array again.
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geobruce
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Re: Most efficient way of importing a dxf to a sketch

Postby geobruce » Wed Aug 28, 2019 6:43 am

TheMarkster wrote:
Tue Aug 27, 2019 7:57 pm
phpBB [video]


honeycomb_circle.FCStd

These hexagons don't have the rounded corners. If you want that you might be able to replace the HoneycombHexagon object as the base of ExtrudedHexagon with one of the rounded hexagons. I would see if I could select all the edges and make a compound, then extrude the compound (this would be extruding a single rounded hexagon). Then make that extruded rounded hexagon the base for the 2 draft arrays --HoneycombArray1 and HoneycombArray2.

Using compound explode on the Fused_Arrays object is the key to being able to individually delete the extruded honeycombs from the array to get the diamond shape. If you change the size of the array you will have to probably explode that array again.
Whoo!! Thank you this is a really nice example. I was able to make it in openscad, but your file is a great help! thanks
Attachments
hex.PNG
hex.PNG (143.13 KiB) Viewed 398 times