Posts from — September 2010
Nope, not the kind of models you find at Model Mayhem; this post is all about finding 3D models of your PCB parts.
You can always make your own, but unless you are an MCAD software expert, rolling your own will take a lot longer.
So far I haven’t had to make a model, but I’ve only used connectors, which typically have STEP or IGES models available from the manufacturer.Â Â But many electronics manufactures do not provide models.
Here are some good model sources:
- Always check the manufacturer first, especially for electromechanical products (connectors, switches, etc).Â You might have to register first.Â Also, sometimes you can get a model by asking (I’ve done that successfully with Amphenol).
- Check out general purpose CAD part libraries.Â I haven’t used any yet, so I don’t have any personal recommendations.Â Ten Link’s list looks like a good starting place.
- You might be able to use MCAD vendor specific user generated CAD libraries.Â If you have good import options (e.g. Alibre Design Expert) you can try importing Solid Edge, Pro/E, or SolidWorks models.
- Pay for model creation, using either a free-lancer or a company such as Simplified Solutions.
- For MCAD software with an API (which includes Alibre Design), you can use this API and information (for example, from an IDF file) about the part to automatically create models — or pay for someone else’s add-in.Â My earlier post has some more information on this approach.
- You might be able to use STL, Sketchup, or 3-D POVRay models developed for projects such as Eagle’Up or Eagle 3D.Â Sycode makes affordable Sketchup and STL importers for Alibre.
- There’s always Google and other search engines.Â I place web search near the bottom because a lot of models are hidden where search engines can’t find them.
- Do it yourself; in that case, I recommend spending a lot of time and some money learning how to model well (to save you time overall).Â The “some money” is best spent on books (such as
Introduction to Solid ModelingNOTE: Learn3DCAD website is no longer active) or videos, although don’t forget to search for free resources and check out what came with your MCAD software.
Simplified Solutions does have some interesting solutions, including:
- An existing library of electrical components in STEP format.Â Pricing is reasonable for professional use at $550 for 50 models or $1700 per year for unlimited models.
- 3D part creation at a reasonable price ($650 for 20 parts, but check on the details; you probably need to provide data in a format they like, e.g. IDF, which for Eagle PCB users means you’ll have to update your library with IDF information).
- 3D PCB model creation (they model the entire PCB).
September 13, 2010 No Comments
Machine Design has an article on Do It Yourself Manufacturing, basically talking about small (often 1 person) niche companies doing design with CoCreate PE or Alibre Design and manufacturing using personal CNC tools from Tormach.
September 3, 2010 No Comments
I don’t write much about the latest mechanical CAD news, because others (like Deelip) already do it better than I can.Â But, since I write a lot about affordable MCAD, it’s time for a brief update on two players:
- Alibre has replaced the $97 Design Standard with the $99 Personal Edition.Â The PE is useless for my uses (such as modeling PCBs) because it won’t import or export STEP or IGES files, although at least you still can do a basic file export to 3D PDF.
- The cheapest version that can handle STEP files is Design Professional, which is currently $599; Alibre’s price do move around a lot.Â Since Alibre runs a lot of specials, especially for existing customers (e.g. PE or Standard users), you should be able to upgrade for less if you wait a while.
- But I’m very happy Alibre is keeping the Standard edition alive for current users.Â I plan on staying on maintenance as long as Alibre continues to provide Standard upgrades.
- VX dropped the VX Innovator and Innovator Light products a while ago without saying anything at all.Â So if you’re interested in Innovator, well, too bad.
- My guess is that this is related to the news that China’s ZWCAD ZWSOFT (maker of the ZWCAD AutoCAD clone) has bought VX; VX will be staying in Florida, but the VX product line will become ZW3D, possibly with significantly lower prices.
September 2, 2010 No Comments
In this post, I have a few final notes about extruding Eagle PCB DXFs.
All the files I mention are available in a ZIP file here Extrude Alibre.zip
The basic idea is simple: I have a sketch with an outline (the PCB borders) with holes in it (pads and vias) that I want to extrude.Â The picture below shows a simple case.Â On the left, there is a rectangle with a circle inside it (Extrude-DoubleCAD.dxf, which I created in DoubleCAD, and then imported into Alibre).Â On the right I extruded it (Extrude-DoubleCAD.ad_part).
So what can go wrong?Â Here are some situation where Alibre Design will not extrude your sketch:
- Overlapping objects
- For example, when two lines on the same layer both cover the same area.Â The picture below shows two thick lines (outlined so it’s clear) overlapping at an intersection.
- A thick rectangle will extrude OK, but you can’t make one in Eagle PCB (Eagle will only create filled rectangles).
- If the lines have zero width, they do not overlap.Â So it’s best to make sure your board’s borders in Eagle PCB have zero width.
- But even if you use thick borders, if you export (using my modified DXF ULP) with the Use Wire Width option off you will have a usable DXF, because in this case the ULP resets all wire widths to 0.Â Â Since you should always export with Use Wire Width off, it’s probably OK to use thick borders, but I always still set my borders to zero width.
- Overlapping lines on different layers
- This is the same as #1, except the lines cross each other on different layers.Â For example, if you have a border on more than one layer in Eagle PCB, and export both those layers to the DXF, then Alibre will not extrude that DXF file.
- The Extrude-Different Layers.DXF file shows this scenario; below is the error message when I import and try to extrude it.
- Extruding PCB traces or silkscreen text.
- It’s possible to create traces or text that Alibre will extrude, but the standard DXF ULP’s output is useless.Â You would have to create a very different DXF ULP.
- Below is an example of a DXF (Traces+Text-Extruded.dxf) and extruded part (Traces+Text-Extruded.AD_PRT) that gives an idea of what DXF exported from Eagle PCB would have to look like.
- Instead, below are some screen captures of actual Eagle PCB DXF ULP output showing the results (for no wire width, wire width, and filled wire width).Â Alibre will not extrude any of these, and I haven’t found a way to overlay a sketch or bitmap on top of a surface.
September 1, 2010 1 Comment
I mentioned in the previous post in this series that you cannot use the standard Eagle DXF ULP to generate DXF files that Alibre can use.Â Now I will go into a little more detail.
All the files DXF files I mention are available in a ZIP file here Extrude Alibre.zip
What are the problems with the normal DXF ULP?
- It creates the pads, not the drill holes.Â The picture below shows, in green, the pads created by the normal DXF ULP.Â I added the drill diameters in white using DoubleCAD.
- Notice the greenÂ squares (which I use for pin 1).Â I haven’t seen a square drill bit yet…
- Notice the the green square and green circle are much larger than the white circle.Â This is because the DXF ULP is creating the pad outline; for each pad, Eagle adds some copper area around the drill diameter (how much depends on the active design rules).Â Â But we want to extrude the actual hole size through the PCB, not the pad (drill area + copper area).
- You can get around this by creating a special set of design rules that does things like set all pad shapes to circular, pad size to the drill size, etc.Â And you’d better remember to re-apply your normal design rules (or you’ll end up with a worthless board).Â This approach will work OK for SolidWorks (I’ve tried it), but still doesn’t work with Alibre, because of other problems listed below.
- The DXF ULP creates the pads using object blocks (with different blocks for the different pad shapes).
- The ULP creates two identical blocks right on top of each other on the same layer (17, Pads).Â Alibre will not extrude sketches with overlapping objects.
- For some reason, Alibre does not copy the blocks correctly.Â When I imported the DXF into Alibre, they appeared at the right location, but when I copied the sketch to the new Alibre part, they moved to a totally wrong location.Â The picture below shows this with the DXF (Extrude-Different Layers.DXF) on the leftÂ and the part (Extrude-Different Layers.AD_PART) on the right — the pads have moved far to the right.
So what did I do?Â Well, I didn’t have a lot of time, and I’m not a DXF expert, so I made the minimum changed required for Alibre to work:
- I changed the Via function to always create a circle with the drill diameter on the dimension layer (layer 20).
- I changed the Pad function to always create a circle with the drill diameter on the dimension layer.
So far these changes have worked for me, but I should note that AutoCAD 2000 doesn’t like my changes (I haven’t tried newer versions).
The final topic: a bit on the DXF ULP options.
- Output file is the name of the DXF file that will be created.
- Always vector font should force a vector font to be used, but I haven’t test this feature.
- Unit selects whether to use inches or millimeters.Â Always remember the units you choose, because when you import a DXF into Alibre Design, Alibre needs to what units you used.
- Below I show the same simple board creating DXFs using 1) no wire wire or fill areas, 2) using the wire width option only, and 3) using the wire width and fill areas options.Â For extruding PCBs, you should never select the Use wire width or Fill areas options.
September 1, 2010 4 Comments