How to find AutoCAD drawings of parts on Digikey

Was it always this easy? How could I have not known?

First, know the manufacturer of the part I want a CAD file of the package of.

Then find that manufacturer on this list:

https://www.digikey.com/en/resources/3d-models

From the manufacturer's link on that page, again find the part. If the part has a CAD model, it will be findable when narrowing searches from this level down.

The part will have a link to the cat files on the manufacturer's site, which may or may not be correctly indexed.

My technique for making assembly drawings

Assembly drawings seem like they should be quick to throw together, because all that needs to be done is to copy and paste the drawings of various parts together. However, the drawings for all the parts are all either done in a variety of different drawing tools or have to be found from vendors, many of whom aren't just giving out free DXF files. So a big wad of different software is needed to put everything together. Here's the list:

Main drawing tool: I would use AutoCAD but it's bloated plus it's expensive and nobody wants to buy it for me. So I'm using DoubleCAD XT which is free for some reason.

To convert front panel drawings: All our front panels are done in Front Panel Designer, which exports to DXF. Astonishingly though, FPD is exporting 3D DXFs, which cause me problems because I am making 2D views and DoubleCAD XT unhelpfully goes nuts trying to render holes that are 3D. The solution is to explode the 3D drawings multiple times in Model Space in DoubleCAD, then select the entire mess and scale Z=0 to flatten the parts. The downside of this is that this results in the tops and bottoms of holes and edges being rendered twice. There's probably a more elegant solution but I haven't had time to figure it out.

To convert board silkscreens to DXF: GerbView is a tool that you can get a trial version of online, but it has proven to be so useful that I had to just buy it. It can be bought from here: http://www.gerbview.com/download.html GerbView can output any layer as PDF, DXF, or other formats. The downside is that the scaling gets mangled; I think that it is outputting the DXF in metric units but I am reading it as English units in DoubleCAD. So to read the DXF that GerbView produces into DoubleCAD requires rescaling before the image can be pasted into my assembly drawing. While searching for tools to view and convert Gerber drawings, I also found GBR2DXF here, and it seemed to be free, but the download process required registering for a password and it seemed like too much information to give out so I didn't try it.

To convert part drawings from PDF to DXF: Many manufacturers will release PDFs of their part drawings, or sometimes just line drawings of their parts. To paste these into my assembly drawing, I have a couple of techniques. The main one is to use a PDF to DXF converter program called Aide PDF to DWG Converter. It uses some kind of algorithm to trace PDFs, and the result is often shaky and poorly aligned if you zoom in but it is possible to then import the DXF and trace it with regular shapes. It has a free trial version but I'm probably also going to buy it. For really clean PDFs of things that were mechanical drawings to begin with, I can just give it the PDF file name, do the conversion, then import the resulting DXF and do cleaning up. It also produces results that are at an incredibly huge scale, so downscaling to convert to 1:1 is also necessary. For drawings where all I have is a JPG or other raster image, I first convert the image to PDF using PrimoPDF or CutePDF.

Some PDFs are shaded or have other features that make them not convert to DXF well. Sometimes I have to make a drawing from a photograph. In those cases, I can feed the drawing into an online tool that produces a black and white raster drawing that looks close enough to a line drawing that I can convert it to PDF and then feed it into the Aide converter. That online tool, oddly enough, is a service for quilters, it is called RapidResizer Stencil Maker. Again, the results of this tool are just approximate enough to produce a DXF that can be cleaned up and traced.

How to make isometric drawings in AutoCAD

I wanted to show an isometric drawing of my assembly, but of course I wasn't actually using AutoCAD. It seems from the following link that it might be pretty easy to do it in AutoCAD:

https://autocadtips1.com/2012/07/27/intro-to-isometric-drawing/

It turns out to be super easy to gen up an Isometric view from a 2D 3-view drawing! I found one video that explains everything very well, and then I began to realize that a few of the other links on the subject that I found were saying the same thing.

In short, the procedure is: Take your top view, rotate it by +45 degrees, then scale the Y axis by 0.57735. Take your front view, also rotate it by +45 degrees and scale its X axis by 0.57735, then rotate it by -30 degrees. Take your side view, rotate it by -45 degrees, scale its X axis by 0.57735 and then rotate it by +30 degrees.

Here's the video:

https://www.youtube.com/watch?v=fs71w6UhXiM

Here's a super awesome page that shows exactly the same thing but with words and pictures:

http://www.intellicad.org/articles-and-press-releases/bid/205888/2-D-construction-technique-to-create-an-isometric-view

Here's a completely different way to do isometrics in AutoCAD using the SOLPROF, SOLVIEW, and SOLDRAW commands, which of course are not part of the free knock-off DoubleCAD that I am using:

http://www.maelabs.ucsd.edu/mae_guides/autocad/3d_to_2d.htm

DoubleCAD XT 5 flatten

So, for some reason DoubleCAD XT is free and I've been using it until I can find my old AutoCAD CD. DoubleCAD is so like AutoCAD it's eerie.

I need to make fiddly official drawing files of my Front Panel Express panels. No problem, Front Panel Express exports to DXF. I can open the DXF file in DoubleCAD just fine. Just select all, paste into a drawing border in paper space in a drawing file and done, right?

Unfortunately not. The result looks fine, but after saving and reopening, all holes and standoffs on the panel come up painfully rendered with thousands of cross hatches apparently an attempt to show the holes' depth. It seems that Front Panel Designer exported the front panel as 3D DXF which is admirable but for some reason when I paste those 3D objects into my flat drawing in DoubleCAD, DoubleCAD it wants to do something special for me.

No problem, just flatten the DXF from Front Panel Designer, right? No, for some reason DoubleCAD XT 5 doesn't have the "FLATTEN" command like AutoCAD does. On the TurboCAD forums this feature is frequently requested, and although TurboCAD, DoubleCAD's parent company, gives the illusion at least of being a lot more sensitive to their customers than say EagleCAD, there is still no Flatten command. So customers post their favorite workarounds in the forums. There may be some trick to using the "place on workspace" command, but most workarounds that I've found so far involve editing the panel in Model Space, which is 3D, exploding all blocks, selecting everything and doing a cutclip and then pasting into paper space which supposedly flattens the exploded objects.

Sometimes this doesn't always work they way I expect however. Sometimes when I think I've flattened the model, I save it and reopen it and it shows the depth rendering still. My present theory is that I need to use the "explode" command several times. The last time I got it to work, the process seemed to be that I selected everything, used explode several times (which can only be done in Model space), then manually set the SizeZ for the entire group to 0, then cut everything and pasted it into Paper space and then back into Model space to verify that SizeZ stays 0, then saved and reopened to verify that SizeZ was still 0 and there was no extra rendering.

Here are a couple of forum threads where folks suggest their methods for flattening drawings. Many writers seem to agree that using a third application, ProgeCAD, is the easiest answer but I really wanted something that would do the job entirely in DoubleCAD.

This thread mentions ProgeCAD, talks a lot about something called pick-point hatch which I don't understand, somebody proposed the cutting and pasting into Paper space to flatten, and somebody else mentioned needing to use explode first if there are 3D blocks. Manually setting Z=0 is also mentioned, also a different command to change the elevation although the command syntax is not clear: http://forums.doublecad.com/index.php?topic=446.0

Here is another forum thread where setting Z=0 is mentioned, although it also mentions using the "place on workplane" command after that which never seemed to help me. ProgeCAD is also mentioned: http://forums.doublecad.com/index.php?topic=684.0

Here's how to do it in AutoCAD: https://knowledge.autodesk.com/support/autocad/troubleshooting/caas/sfdcarticles/sfdcarticles/How-to-flatten-a-drawing-so-all-linework-is-at-an-elevation-of-0.html