PDA

View Full Version : DXF importer problems!



FelixPQ
02-07-2012, 04:53 AM
Hi,

I just realise the importer is capable of reading dxf spline elements but incorrectly. It would seem it doesn't use the weight info and or the degree of the element it read in. This makes it useless for this kind of dxf files.

IMHO a $200 piece of software should be much better then this.

Though I've found a solution, I still feel it's a shame and I would strongly request LHR would do something about it and soon but if I'm alone, you know what's going to happen. This is why I posted here first hopping to see what others think about this.

Thanks,
Felix http://forum.carvewright.com/images/icons/icon9.png

mtylerfl
02-07-2012, 11:11 AM
Hi,

I just realise the importer is capable of reading dxf spline elements but incorrectly. It would seem it doesn't use the weight info and or the degree of the element it read in. This makes it useless for this kind of dxf files.

IMHO a $200 piece of software should be much better then this.

Though I've found a solution, I still feel it's a shame and I would strongly request LHR would do something about it and soon but if I'm alone, you know what's going to happen. This is why I posted here first hopping to see what others think about this.

Thanks,
Felix http://forum.carvewright.com/images/icons/icon9.png

Hi Felix,

What DXF filetype version are you saving/exporting to, and what software are you using to create your vectors? I typically export to AutoCAD 2004 DXF and the imports into CarveWright seem fine. I create the bulk of my vectors in CorelDRAW, then export to DXF from there. I'm puzzled what you are running into. Perhaps you could post an example of a DXF file you are having trouble with?

FelixPQ
02-07-2012, 02:14 PM
Hi,

I have no idea of the version per say it is but I know it open incorrectly in DXF importer and perfectly in Rhino, BobCad, and a few other programs I have as well. I know my DXF files are 3D but I take care to just export curves and lines on a flat plane.

All the geometry in this file are circles and they don't look much like circles in the importer. I would rather have the importer failed instead of having this kind of result.

Thanks,
Felix

dbfletcher
02-07-2012, 03:11 PM
Just for fairness, I tried to open your dxf in Autocad 2011. It croaked saying it was an invalid dxf file. I did also import it with Corel.... which was able to import it, but as you can see.. circles are NOT circles.

So you cant really fault the dxf import for not handling improper files. There are a lot of things I also complain about with the dxf importer, but I cant side with you on this one.

Edit: I also imported in to one other CAD package (Anvil) and it did import ok and visually the elements do appear to be circles. However, when I click on any of them and have the program identify the object, they are all spline curves. Typically in CAD packages a circle is represented as a centerpoint with a radius. Seems kind of silly to use a spline to represent a true circle.

dbfletcher
02-07-2012, 03:37 PM
I also recreated your drawing as circle entities... try to import this dxf and see what happens. I'm not at home right now to look at it in my dxf importer.

FelixPQ
02-08-2012, 05:29 AM
dbfletcher,

I can understand the dxf file format as so many dialect that it's complicate to find a library that works correctly with each of them. I also now the program I use to generate the dxf file, output all NURBS curves as splines elements in the DXF file. As you verified yourself some programs read them correctly and some don't but always as spline.

I know the solution to all this is to start with compatible geometry in the first place but that would requires redrawing everything from scrath in my case. Since my program (Moi3D) can export to AI also, I'll use that route from now on. I might find some use for the DXF importer in the future but for now it doesn't work for me with my current workflow.

One last thing, I know my program DXF exports are compatible with all recent high end CAD, it was modified recently to be compatible with Rhino 5, I can understand not so recent program can have problems with it. Anyway, the important thing is that I have various mean to use the DXF importer fairly nice features, at least those it have, even if it requires me to draw everything with a low end cad compatible program.

To machine the part below, I've chosen the stl route to simplify my life but as you know this means the CW machine will spent much of it's time carving nothing. In order to machine it "effectively" would mean a lot of work both creating the toolpath geometry manually, setting the depth of each polygone "path" manually as well and I also have to use a jig or carrier board of somekind because as designed the part is 3/4" thick and will most likely break something. If only the dxf importer could use the actual 3D toolpath geometry generated elsewhere in the form of a dxf file, then I would call that elegance and worthwhile.

Edit: I just tried another mean to use my original Moi3D design to generate DXF file, I think one can say problem solved! Here is a DXF file create this way. The DXF importer would still be much more usefull if it could import 3D dxf "toolpath" and allow us to select a bit, max bit depth and use the imported toolpath as the target depth, maybe in another life...

Regards,
Felix

mtylerfl
02-08-2012, 07:11 AM
Hi,

I have no idea of the version per say it is but I know it open incorrectly in DXF importer and perfectly in Rhino, BobCad, and a few other programs I have as well. I know my DXF files are 3D but I take care to just export curves and lines on a flat plane.

All the geometry in this file are circles and they don't look much like circles in the importer. I would rather have the importer failed instead of having this kind of result.

Thanks,
Felix

Hi Felix,

When you save your DXF files, you do NOT want to save them as 3D DXF...save them as regular 2D. I imported your DXF into CorelDRAW X3 and got just a single line. I also tried importing into Aspire...the import yielded nothing at all EDIT...EDIT: Correction...Aspire DID import the DXF (it was off-screen and I just noticed it...I imagine why it worked is because Aspire CAN import 3D DXF - well, at least this one! I don't think it fully supports a 3D DXF either.)

I'm thinking this is the main issue...saving the DXF in an improper format for the task at hand...the CarveWright DXF Importer needs 2D DXF.
It's amazing the CarveWright DXF importer gets anything at all (since it isn't designed to support 3D DXF). I tried importing your sample DXF and see the distortion of the circles. I think if you save your vectors as "regular" DXF (NOT 3D) the vectors will import just fine. Let us know.

FelixPQ
02-08-2012, 10:47 AM
mtylerfl,

as I said in my last post, I've found a pretty easy solution using my original 3dm files created in my favorite 3D Nurbs program, I just import the 2D geometry I've extracted from my original as a 3dm file into another 3d CAD/Cam I have and export to a dxf file from there instead. It take a few seconds and I obtain well behaving basic geometry the DFX importer as no trouble importing correctly as far as I've tested it for now. Basically, I can use my DXF importer without have to redraw anything which is the minimum I wanted.

I can understand I bought myself a pretty expensive 2D DXF importer that allows us to create 2D geometry externally that would otherwise be a real pain to create in designer. But the importer could be so much more useful then that if only... This machine as all the necessary hardware both mechanic and electronic necessary to be a full fledge CNC machine within it's physical limits and unfortunatly we have access only to a somewhat limited subset of its full potential. It's a bit like having a color printer and behing able to print only in black and even if it did a great job at that, it would still be a shame and lots of wasted potential.

Regards,
Felix

mtylerfl
02-10-2012, 06:34 PM
Hi Felix,

Thank you for your comments and ideas.

We have pretty decent capability with the CarveWright for bringing in both 2D and 3D data created in "outside" programs. The DXF Importer is designed for importing strictly 2D vectors...the STL Importer is designed for importing relief and full 3D models. As long as we work within the parameters of what the tools were created for, we've got some fairly powerful tools at our disposal. As time goes on, more options and perhaps even some new tools, will become available to accomodate the CarveWright's intended audience/market/price point.

FelixPQ
02-10-2012, 10:33 PM
mtylerfl,

I can understand the CW system is pretty strong at what it does and it does it elegantly as someone suggested. But knowing the machine as all is needed to fully control it's movement in all 3 axis I feel very frustrated I don't have the means (yet) to fully control it myself either with some scripting language, via gcode (preferably) and or via an external controller like Mach3 for example.

Anyway, now that I have spent close to $2K for the machine and add-ons LHR is probably happy but I'm not.

Regards,
Felix

mtylerfl
02-11-2012, 05:42 AM
Hi Felix,

Thanks again for sharing your point of view. I hope you will become as happy as I am, along with so many other CarveWright owners. It's an amazing machine for such a bargain price. There's almost 'nothing' one can't do with it, if they put their mind to it. I've mentioned it before - - I don't think I've ever had this much fun since getting my CarveWright machines.

All the best to you, and please let us know if you need help or have any questions working within the current CarveWright system design for your projects. I'm looking forward to seeing what you create!