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The Turbulent MCAD Market

I’m not interested in being a 3D Mechanical CAD (MCAD) journalist, but since has lot happened in the last year, it’s time for my summary.

The “Big 4” have been up to a lot:

  • SolidWorks is being brought closer to its parent (Dassault Systèmes).  It’s highly probably that a new version based on the CATIA V6 CGM kernel is coming, possibly cloud based.
  • PTC has put Pro/E out to pasture, and is busy trying to get its new Creo components out.  Creo is supposedly to be modular (including history based and direct modelling modules) and app-oriented.  The vision sounds nice, but I suspect that the actual operational and pricing details will make it evolutionary, not revolutionary.
  • AutoDesk is adding direct modelling to Inventor via the Fusion program.  The free 123D program is a cut-down, stand-alone version of Inventor fusion.  123D looks quite useful, but I expect it’ll be neutered if it starts to impact Inventor revenues.
  • Siemens PLM Systems is finally getting its Solid Edge act together.  They’re concentrating on making Solid Edge the best program for machine design, and Synchronous Technology V3 (direct and history based modelling) has been getting good reviews.

There’s been even more change with many of the smaller players:

  • 3D Systems recently bought Alibre.  A few months ago Alibre introduced a $1500 bundle consisting of a RapMan 3D printer, Alibre Design Personal, and MoI.  I’ll be interested to see what happens next.
  • The $97 Alibre Design Standard deal really was a great deal, just for the translators and 3D PDF output alone, but the recent pricing and capability changes (e.g. removing almost all import and export options from AD Personal) really neutered the entry level version.
  • I’m hopeful that 3DS will provide resources so Alibre can keep improving (especially since I just paid for Alibre maintenance!)
  • ZWCAD of China bought VX, and renamed it ZW3D.
    • On the positive side, ZWCAD is trying to treat customers well, there have been no US layoffs as far as I know, they have been investing money into ZW3D (licensing more components, adding more developers, etc), appear to be listening, and probably have a good upgrade policy.
    • On the other hand, it’s taking a  (long?) while for them to get up to speed, they’re going to a reseller-only approach (e.g. you have to contact your reseller to upgrade), and they really need to spend some money and hire some good US marketing folks.
    • For example, when ZWCAD took over, they gave all customers a free upgrade to the next level.  So if you had VX Innovate, you got upgraded to ZW3D 2010 Standard, if you had VX standard, you were upgraded to ZW3D 2010 Professional.  I think this was a great gesture, but ZWCAD never received any publicity for this.
  • Think3 users are in a huge mess, and should start looking elsewhere, since there are now two versions, one from Versata, and one from the Italian bankruptcy trustee.  Deelip is the place to go for all the details.
  • I plan on discussing my experiences with Alibre, ZW3D, and 123D, but I won’t make any promises on how often I’ll have time for such posts.

    August 2, 2011   No Comments

    Eagle 3D PCBs with Alibre: Assembling the Model Part II

    Before starting to put all the pieces together, spend some time planning.   Things to think about include:

    • What is your naming convention?  A good naming convention for parts and assemblies really helps you remember what is what.  Which is a more useful name for a connector model, Part_21 or AMP 5499206-IDC-26?
    • How are you going to assemble the part?  Are you going to use any sub-assemblies?  Good use of sub-assemblies makes assembling the model easier and more logical.
    • Do you have all your part models?  I like to have all my models ready before assembly, but you could start with what you have, and download or create as you go.
    • Do you need to modify any manufacturer provided models?  For example, your part might be slightly different from the closest manufacturer model, or you may need to modify the part (e.g. by adding reference geometry) so you can easily add constraints.
      • I’ve come across both these cases, and will discuss them more in the future.
    • Are you going to directly import your manufacturer models into your assembly, or convert them into Alibre parts first?  Alibre Design 2011 can directly import STEP, SAT, and IGES parts into assemblies.
      • IIRC, previous Alibre versions couldn’t directly import into assemblies, which is why my current designs convert all imported parts into Alibre parts.

    Here are my tips on adding constraints:

    • Come up with a naming convention for constraints: J1_Align_Pin1 provides much more information than align22.
    • Position the parts so you can see all the features you plan on using to mate the parts together.  I really like using the triad tool, with minimum motion mode off.
    • I’ve had much better results using the manual constraints dialog than trying to use quick constraints.  Sometime I’ll give quick constraints a try again.
    • I’ve found it’s always necessary to move and zoom all around, and every time I use the icons, my constraints dialog goes away, so shortcuts are the way to go:
      • Pan: press and hold middle mouse button, then move mouse pointer
      • Rotate: position the mouse pointer where you want to rotate, then press and hold right and left mouse buttons, then move mouse pointer.
      • Zoom in: press Page Up
      • Zoom out: press Page Down
    • Be careful where you click; it’s easy to select a feature you don’t want.
    • I like anchoring one part (for example, the PCB) so I know which part will be moving when I add constraints
    • Check the defaults.  Often, the mate constraint will show the current distance between parts, so I have to change it to zero.
    • Use your PCB layout as a guide.  OK, if I could get Alibre to handle the silkscreen layer this wouldn’t be necessary, but it’s handy when I have a PCB full of holes and no silkscreen information on the PCB model.

    January 13, 2011   2 Comments

    Eagle 3D PCBs with Alibre: Assembling the Model Part I

    The final step in creating a 3D PCB model is to assemble all the pieces together.  Normally Alibre assemblies are created by constraining the parts.

    A constraint limits how two parts can be located relative to each other.  Three constraints fully constrain a part.  For example, think of mating a through hole connector with 10 pins in one row to a PCB.  You could add three constraints like this:

    1. Use an Align constraint to align the axis of the connector’s pin 1 with the PCB hole for pin 1.  Now the connector is limited to two degrees of freedom: it can move close and farther from the PCB and it can rotate 360 degrees  around the pin-1/hole-1 axis.
    2. Use another Align constraint to align the axis of the connector’s pin 10 with the PCB hole for pin 10.  Now the connector cannot rotate: it can only move close or father from the PCB.
    3. Finally, use a Mate constraint with a zero offset to mate the bottom of the connector with the top of the PCB.  Now the connector cannot move at all; it is attached the the PCB just like you had perfectly soldered a perfect connector to a perfect PCB (pins centered in the holes, connector just touching the PCB, etc).

    That sounds pretty easy, right?  Well, the reality is often different.  Extruding a PCB is straightforward.  Mating parts together is not; there are many possible ways of mating the parts together, and the best approach depends on the specific parts and PCB.  I think MCAD assemblies are complex enough that an expert could write a book just about assemblies (and I’m definitely not an expert).

    I haven’t found a lot of practical information on Alibre assemblies.  My findings so far:

    • You should definitely read the Alibre Design User Guide chapter on assemblies.  It covers what’s available, including about 20 pages on constraints, but is brief and descriptive.  It does not give any examples or practical advance.
    • Based on the table of contents, the Learn 3D CAD book also only covers constraints briefly (about 20 pages), but still looks like it’s worth the price, since it has a real world example, and advice on overall design (top down vs bottom up).  I’m planning on getting the PDF version when the 2011 update is available.  Note 10/5/2011:  the Learn3DCAD website is no longer active, so this is no longer an option.
    • The Alibre forums look useful if you have a specific question, but aren’t a tutorial.  Also, if you’re on maintenance, there’s always tech support for specific questions.
    • I’m not sure how useful Alibre’s paid training materials (DVD, exercise book, online seminars) since they don’t provide detailed information on the contents.  I suspect they wouldn’t cover some of the problems I’ve had.

    Next up in this series: some specific tips from my experience.

    January 11, 2011   No Comments

    Eagle 3D PCBs with Alibre: What’s Left?

    I haven’t forgotten about my Eagle 3D PCBs with Alibre series.  There is one big topic left:  putting all the pieces together using Alibre assemblies.  Unfortunately, my experience is that mating parts to create assemblies is often very tricky (especially when you’re using imported parts), and there’s not a lot of resources.

    I’ve done a fair amount of research, but it’s hard to give the same kind of step-by-step instructions for mating parts in an assembly that I did for extruding the PCB.

    Also, I’ve just re-done my blog PC (a Thinkpad X61t) with a bigger hard drive and Windows 7 64-bit, so that’s sucked up a lot of time recently.   (Side note: there’s not a lot of 64-bit software out there yet.  But so far I’m quite please with the upgrade.  Alibre Design 2011 does have a 64-bit version, but only for Professional and Expert users.)

    What I’ll probably do is write an article (hopefully in the next week) with some notes on how I mated everything together.  I’ll post the files in Alibre Design 2011 format so you can see what I did.

    Then this series will be complete.  But I do plan on writing about some Alibre tips that are sort-of related to this series.  And I do have a new series planned that’s more automation related.

    November 20, 2010   No Comments

    Alibre Design and DXF Blocks

    Many DXF files use blocks.  A blocks defines an object, which then be placed in many locations, and each location can be scaled and rotated individually.   For example, the standard Eagle PCB DXF export ULP uses one block for each different style of pad (circular, square, etc), and then scales, rotates, and places these blocks for each individual pad.

    But blocks aren’t so great when you’re importing them into Alibre Design (AD).  I’ll look at a few issues by trying to extrude the Phoenix ZFK3DS 1,5-5,08 (1704415) terminal block outline; for example, I might want to model a cover for the end block (1704554).  The files are available in a ZIP archive here Alibre and DXF

    The DXF file provided by Phoenix uses blocks for all the views.  I removed the views I didn’t want; the resulting file is Phoenix 1704415 Profile – block.DXF, shown below in DoubleCAD XT.  You can see the blocks on the right.

    Phoenx 1704415 Profile using blocks

    Phoenix 1704415 Profile using blocks

    I can’t extrude that profile; I need to remove the pins and the pegs.  But I can’t edit the block in the drawing (left side of screen).  In the Alibre sketch mode, I can only move it, delete it, or copy it.   In the DoubleCAD drawing I can only scale, rotate, move, copy, or delete the block.

    But I can edit the block in DoubleCAD by selecting the block in the block tab (shown on the right), and pressing the EC (Edit Content) button.  The block is now displayed in the drawing area, and I can edit it, then press the check mark (next to EC) when I am done.  The final result is shown below and in the Phoenix 1704415 Profile – block for Extrude.dxf file.  Note that when you edit a block, all objects based on that block will update when you finish editing.

    Phoenix 1704415 Profile - using blocks, edited

    Phoenix 1704415 Profile - using blocks, edited

    Another approach is to change to a no-block approach by editing the block you want, selecting everything, copying it, closing the block editor, pasting the copied part into the main drawing, and finally deleting all the blocks in the block tab (when you delete a block, all the objects based on that block are deleted).  The result is in the Phoenix 1704415 Profile – No Block.dxf file.

    With the no-block file, you can delete the stuff you don’t want in either DoubleCAD or import it into Alibre Design and delete it in AD’s sketch editor.  The no-block approach isn’t good for a circuit board full of blocks, but it works great for a single profile.

    There are some other differences between the block and no-block approaches in Alibre Design.  Alibre has a non-obvious approach to pasting in sketches: “normal” pasting (Ctrl-V) always pastes the clipboard content in the same position relative to the origin; paste stamping (Ctrl-T) lets you place it where you want (press ESC when you’re done pasting).

    The approach is always the same for getting a DXF file into a sketch: import (which opens an Alibre drawing), open sketch mode, select everything, and then paste it (Ctrl-T or Ctrl-V) into the desired sketch.

    So far I’ve found that blocks don’t paste correctly; they get pasted with some sort of an offset, whether using paste or the paste stamper.  Non-block DXF drawings paste correctly.   But it’s easier to move blocks in Alibre sketches: just select them and drag.  To move a non-block figure, you have to select all of it, cut it (Ctrl-X), paste stamp it (Ctrl-T), move it where you want, and then quit stamping (Esc).

    Here’s a picture of the finished profile extruded in Alibre:

    Extruded DXF profile

    Extruded DXF profile

    I’ve used DoubleCAD XT for all my DXF manipulations because it’s free and it works for me.  You should be able to do the same things with any other high quality AutoCAD clone.  DraftSight is another free AutoCAD clone worth checking out; it’s available on Windows, Mac, and (real soon now) Linux.

    October 20, 2010   No Comments

    Machine Design on DIY Manufacturing

    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

    MCAD Update: VX, Alibre

    I don’t write much about the latest mechanical CAD news, because others (like Deelip) already do it better than I can.  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.  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.  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.  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.  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

    Eagle 3D PCBs with Alibre: Extrusion Notes

    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

    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.  The picture below shows a simple case.  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).  On the right I extruded it (Extrude-DoubleCAD.ad_part).

    Simple Extrusion

    Simple Extrusion

    So what can go wrong?  Here are some situation where Alibre Design will not extrude your sketch:

    1. Overlapping objects
      1. For example, when two lines on the same layer both cover the same area.  The picture below shows two thick lines (outlined so it’s clear) overlapping at an intersection.

        Overlapping Lines

        Overlapping Lines

      2. A thick rectangle will extrude OK, but you can’t make one in Eagle PCB (Eagle will only create filled rectangles).
      3. If the lines have zero width, they do not overlap.  So it’s best to make sure your board’s borders in Eagle PCB have zero width.
      4. 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.   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.
    2. Overlapping lines on different layers
      1. This is the same as #1, except the lines cross each other on different layers.  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.
      2. The Extrude-Different Layers.DXF file shows this scenario; below is the error message when I import and try to extrude it.

        Errors Extruding Duplicate Lines

        Errors Extruding Duplicate Lines

    3. Extruding PCB traces or silkscreen text.
      1. It’s possible to create traces or text that Alibre will extrude, but the standard DXF ULP’s output is useless.  You would have to create a very different DXF ULP.
      2. 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.

        Extruding Text & Traces

        Extruding Text & Traces

      3. 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).  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.
        Text & Traces - outline

        Text & Traces - outline

        Text & Traces - Wire Width

        Text & Traces - Wire Width

        Text & Traces - Filled Wire Width

        Text & Traces - Filled Wire Width

    September 1, 2010   1 Comment

    Eagle 3D PCBs with Alibre: More on Creating DXFs

    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.  Now I will go into a little more detail.

    All the files DXF files I mention are available in a ZIP file here Extrude

    What are the problems with the normal DXF ULP?

    1. It creates the pads, not the drill holes.  The picture below shows, in green, the pads created by the normal DXF ULP.  I added the drill diameters in white using DoubleCAD.
      Pads created by Eagle DXF ULP

      Pads created by Eagle DXF ULP

      1. Notice the green  squares (which I use for pin 1).  I haven’t seen a square drill bit yet…
      2. Notice the the green square and green circle are much larger than the white circle.  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).   But we want to extrude the actual hole size through the PCB, not the pad (drill area + copper area).
      3. 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.  And you’d better remember to re-apply your normal design rules (or you’ll end up with a worthless board).  This approach will work OK for SolidWorks (I’ve tried it), but still doesn’t work with Alibre, because of other problems listed below.
    2. The DXF ULP creates the pads using object blocks (with different blocks for the different pad shapes).
      1. The ULP creates two identical blocks right on top of each other on the same layer (17, Pads).  Alibre will not extrude sketches with overlapping objects.
      2. For some reason, Alibre does not copy the blocks correctly.  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.  The picture below shows this with the DXF (Extrude-Different Layers.DXF) on the left  and the part (Extrude-Different Layers.AD_PART) on the right — the pads have moved far to the right.

        Problem Copying Blocks

        Problem Copying Blocks

    So what did I do?  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:

    1. I changed the Via function to always create a circle with the drill diameter on the dimension layer (layer 20).
    2. 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.

    DXF ULP Options

    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.  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.  For extruding PCBs, you should never select the Use wire width or Fill areas options.
      DXF no Wire Width and no Fill Areas

      DXF no Wire Width and no Fill Areas

      DXF using Wire Width, not using Fill Areas

      DXF using Wire Width, not using Fill Areas

      DXF using Wire Width and Fill Areas options

      DXF using Wire Width and Fill Areas options

    September 1, 2010   4 Comments

    Eagle 3D PCBs with Alibre: Extruding the PCB

    Extruding the PCB – Overview

    The first step to a complete 3D PCB model is to create the PCB.  The basic approach is to export a DXF outline of the PCB and its holes from Eagle PCB, import it into Alibre, and then extrude it.  It’s not as easy as it sounds.

    Alibre Design refuses to extrude sketches with any overlap.  AD V11 did not show where the errors are, but V12 does (this feature alone makes V12 worth the upgrade).

    If your PCB border has a non-zero width, Alibre will not extrude the PCB because the four corners overlap.  For some reason, Alibre Design does not accept the way the standard Eagle DXF script creates holes.

    I did not have any success getting Alibre Design to extrude the silkscreen or trace layers, nor was I able to overlay the silkscreen or traces as a visible sketch on top the extruded PCB (maybe because Alibre Design does not support surfacing).

    When extruding, CoCreate PE is about as picky as Alibre, but (like AD V12) it highlights what it doesn’t like.  SolidWorks doesn’t have problems extruding the standard Eagle DXF output.  VX Innovator is also less picky; I have successfully extruded the silkscreen layer.

    I made a couple quick and dirty changes to the standard Eagle DXF creation ULP to fix the holes; the result is dxf-fsw.ulp.

    Creating the PCB — Step By Step

    1. Open your project in Eagle, then open the Eagle Board editor with your PCB layout.  I used the FP-SMC-1 project as an example; you can download the files here.
    2. Make sure your borders have a width of 0.
    3. In the Eagle PCB board editor, turn on only the dimension, via, and pad layers (layers 17, 18, and 20).
      Layers for DXF creation in Eagle

      Layers for DXF creation in Eagle

      FP-SMC-1 in Eagle set for DXF creation

      FP-SMC-1 in Eagle set for DXF creation

    4. In the Eagle PCB Board editor, run the dxf-fsw.ulp ULP.
      1. Select a file name for Output file; I used FP-SMC-1.dxf with the appropriate path for my Eagle PCB setup.
      2. The Always vector font, Use wire widths, and Fill areas setting should not matter.
      3. The units do matter: you need to know them when you import the DXF.  I used inches.
      4. Then run the script by pressing OK.
      5. You can download my resulting file here FP-SMC-1.dxf

        Running the dxf-fsw ULP

        Running the dxf-fsw ULP

    5. Close Eagle PCB.
    6. Start Alibre Design.
    7. Select the File->Import menu, select AutoCAD DXF files for the file type, select the file (in my case, FP-SMC-1.dxf), and press Open.
      1. File Units need to match the units you used when creating the DXF in Eagle (I used inches).
      2. I don’t think Maintain Projection matters.
      3. Importing Only Visible Layers makes sense.
      4. Start importing by pressing OK.

        Importing DXF into Alibre

        Importing DXF into Alibre

    8. Select the Sketch->Activate 2D Sketch menu  (or press Ctrl+K).
    9. Select the Edit->Select All menu (or press Ctrl+A)
    10. Select the Edit->Copy menu (or press Ctrl+C)
    11. In the Alibre Home window select the File->New->Part (or press Ctrl+Shift+T)
    12. Select the Sketch->Activate Sketch menu (or press Ctrl+K)
    13. Select the plane to use for your new sketch.
      1. You can name the sketch.  It’s not a big deal in a simple part, but I would recommend named sketches in a complex part.
      2. I used the XY plane.  You can select the plane by either clicking on the plan in the work area, or clicking on the list of planes in the tree on the left (e.g. Planes->XY Plane).
    14. Select the Edit->Paste menu (or press Ctrl+V) to paste the DXF drawing into the sketch.
      1. You could select and move the sketch around if desired.

        FP-SMC-1 DXF pasted onto the sketch

        FP-SMC-1 DXF pasted onto the sketch

    15. Select the Sketch->Activate Sketch menu (or press Ctrl+K) to deactivate the sketch mode.
    16. Select Extrude Boss by menu (Feature->Boss->Extrude) or icon (typically the top right icon).
      1. Verify the correct sketch is selected.
      2. Use To Depth for Type.
      3. Use your PCB thickness for depth (0.062″ or 1/16″ for me).
      4. I reversed the extrude so the sketch is on top (probably doesn’t matter a lot).
      5. Leave everything else with the default settings, except you may want to name the extrusion.
      6. Start the extrusion by pressing OK.

        FP-SMC-1 ready for extrusion

        FP-SMC-1 ready for extrusion

    17. Save the PCB using the File->Save As menu (Ctrl+Shift+S); mine is available as FP-SMC-1 PCB.AD_PRT

      The extruded FP-SMC-1 PCB

      The extruded FP-SMC-1 PCB

    18. We are done creating the PCB itself.  Now we have to assemble the board inside of Alibre, so stay tuned.

    Here is the FP-SMC-1 PCB as an Acrobat 3D PDF; if a correct version of Acrobat is installed, you can click on the PCB, and then rotate it and more.

    June 29, 2010   3 Comments