Converting 2010 AutoCAD file to R14 DWG or R14 DXF, lineweights not preserved

[LukeJS]

Hi, I am new to the forum.  I know Release 14 is practically ancient history at this point and I may not be able to get help on converting files to that format from AutoCAD 2010 but would appreciate any help you could give on the matter.

I am trying to convert some simple 2D drawings to R14 from 2010 so I can plot them to a old school pen plotter.  R14 was the last version to support the native ADI driver for the pen plotter.  As a simple example I tried converting the line weights test file found here: http://knowledge.autodesk.com/support/autocad/downloads/caas/downloads/content/autocad-sample-files....

When I save the file as a R14 (R12) DXF and open the same file back in 2010 all the line weights are gone so does that version of DXF not support line weights?

When I save the 2010 file as a R14 DWG and open the R14 DWG file back in 2010 all the line weights are preserved but when I open the R14 DWG file in R14 I get a "Proxy entities" error message which I took a screen capture of in the attachment picture.  Once I click okay on the error the drawing loads but the line weights are not present.

[Alfred.NESWADBA]

Hi,

if you want to plot to a pen-plotter then each color in AutoCAD will be converted to a pen on the plotter. AutoCAD does not know what lineweight the pens have you put into the plotter carousel, so lineweights were not important.

I looked now into a R12-DXF .. and yes, code 370 for lineweights does not exist, if it was supported in R14 or not ... I don't know that now, but again, for plotting with a pen-plotter, it's really not important.

>> When I save the file as a R14 (R12) DXF and open the same file back in 2010 all the line weights are gone

>> When I save the 2010 file as a R14 DWG and open the R14 DWG file back in 2010 all the line weights are preserved

Be careful, you can't save to a R14-DXF, so you compare R12-DXF and R14-DWG ... that are different version PLUS R14 (if my remebering is correct) was the first release able to hold proxies .. here used to not lose the lineweight info when reopend in a newer AutoCAD release.

- alfred -

[LukeJS]

Hi Alfred, thanks so much for the response and looking into this.  I replied to some points you made for clarification.

>> if you want to plot to a pen-plotter then each color in AutoCAD will be converted to a pen on the plotter. AutoCAD does not know what

>> lineweight the pens have you put into the plotter carousel, so lineweights were not important.

AutoCAD does infact know what size pens are in the plotter as you can specify them with my pen plotter ADI driver in R14, it's really cool.  This feature is also in the modern version of AutoCAD if you add a ploter as HP Generic LHPGL plotter but I have not been able to get the generic HPGL plotter driver in the modern version to work with my plotter so I am trying to use R14 just for plotting.  This is why lineweights are key, AutoCAD knows the pen size and will draw as many lines as needed directly adjacent to create one larger line which matches the set lineweight in the CAD file.

>> I looked now into a R12-DXF .. and yes, code 370 for lineweights does not exist, if it was supported in R14 or not ...

>> I don't know that now, but again, for plotting with a pen-plotter, it's really not important.

As said above the lineweight is critical for pen plotting.  You are right I can only output to R12-DXF or R14-DWG.  Thanks for the info on that version of DXF not supporting lineweights.  I know AutoCAD R14 supports line widths, I do not know if width is differnt from lineweights but I can set the width of a line in R14 and it will plot accordingly.  

>> Be careful, you can't save to a R14-DXF, so you compare R12-DXF and R14-DWG ...

>> that are different version PLUS R14 (if my remebering is correct) was the first release able to hold proxies ..

>> here used to not lose the lineweight info when reopend in a newer AutoCAD release.

Sorry, I do not really understand proxies so I am probably missing something key here.  The interesting thing is I can draw a polyline with a thick lightweight in R14, save it as a DWG, then open it in 2010 and everything is fine.  I can't do it the other way around though by drawing a few lines in 2010 and saving it as R14 DWG without getting proxy errors and no preservation of line weights.

Thanks again for your help!

[Alfred.NESWADBA]

Hi,

please don't mix up polyline-width and lineweight.

That are very different things!

- alfred -

[LukeJS]

Thanks for your help Alfred.  Good point, it looks like you can't set the width of a line, only polylines.  R14 supports polyline widths as well, so is there a way to convert all lines in a drawing to ploylines with a width attribute set to the width of the line's lineweight?  This would allow me to export a file to R14 and have the lines output to the correct width.

[jggerth1]

it's been a decade ot two since I dealt with pen plotters -- but we had no trouble using different pen numbers, and putting different weight pens in the carousel.  lineweight in the CAD file was immaterial -- since the color was assigned to pen number.  

[LukeJS]

Thanks for the response JGerth, I am not having issues with pens or pen weights on the plotter end.  The issue is preserving the line weight property when converting to R14 to allow it to be plotted at the correct thickness.  After discussing with Alfred it seems R14 may not support lineweights.  R14 does support polyline widths so is there a way to convert all lines in a CAD file to polylines with a width set to what the lineweight property was?

[Alfred.NESWADBA]

Hi,

>> so is there a way to convert all lines in a drawing to ploylines with a width attribute set to the width of the line's lineweight?

Not really, because of the simple point that these two values can't be set as alternative, the LINEWEIGHT is independent of any scale (viewport scale, plot-scale, ...) whereas a polylinie-width is an absolute value.

You can try that in modelspace, create a layer with lineweight 0.5mm, draw a line onto it (make sure visibility of lineweight is set to on), draw a polyline on that layer and then zoom mode close to the polyline, you'll see how lineeweights work.

If you draw a polyline with a polyline-width ... zooming more close to the poly makes the polyline appear thicker the more close you are.

As long as you only plot with one scaling that you can use _PEDIT to convert lines to polylines, , select them and give them a polylinewidth (e.g. using the property window). But besides of that onyl works with just one plot-scale you also have no chance to assign "polyline-widths" to objects like hatch, dimensions, text, .... and so that is a second reason why polyline-widths are not an alternative for lineweights.

- alfred -

[jggerth1]

No, there isn't anything readily available that comes to mind.  and, although certainly some of the skillful folk in the cutomization group could whip something together, it would break in too many places to be useful.  TEXT or POINTs for example, circles would need to be recreated, and so forth.

I suspect you'll be ahead IGNORING lineweights in Acad, and relying on color.  If you're dependent on R14 style output, then you need to work in an R14 philosphy.

Hopefully you've at least been using lineweights on a BYLAYER basis instead of per entity over-rides.