Alibre continues to restrict Alibre Design Xpress’ functionality; in Xpress 11 after the 30 day evaluation runs out, you can only import AutoCAD (DWG, DXF) files, and export STL files.
I’ve used Xpress occasionally since it was introduced in 2005, and I’ve never had problems importing STEPÂ (or IGES) files until recently.Â Since I mainly use mechanical CAD to model PCBs populated with manufacturer provided part models (typically in STEP or IGES formats), this means Xpress is no longer useful.Â As far as I’m concerned, Xpress is now basically just a trial version — great if you want to evaluate Alibre Design before buying, but not useful on its own.
Since I’m not making any money from the PCBs, my budget for MCAD software is basically $0 (OK, I might go up to $250 for software that did a really great job).Â If I were primarily doing mechanical design, especially for money, then my budget would be different.
I’m still thinking about what I want to do; my default option is to model in CoCreate PE, which only exports STL and VRML files, but at least it imports DWG, DXF, STP, and IGES files, so it’s still easy to model PCBs in CoCreate and check that all the pieces fit together.
Go here for my latest MCAD news posts.
August 7, 2009 5 Comments
The beta currently supports importing, viewing, and exporting IGES, STEP, STL, and Open CASCADE BRep files; in the future, more formats will be supported.Â It is based on Open CASCADE; it is currently free but not open source.
CAD Exchanger does not currently support measuring.Â I prefer that the CAD Exchanger team concentrate on adding and improving its file translation abilities; there are already fine free solutions for measuring STEP files.
I tried CAD Exchanger using the same Norcomp HD26M model I used with other CAD programs.Â The user interface does not currently support drag-and-drop.Â The HD26M model loaded in a reasonable time; 3D performance (rotate, zoom, pan) is good, even on a laptop with crappy Intel graphics.Â CAD Exchanger provides a nice selection of pre-defined views.Â I didn’t try exporting.
Here is a picture of CAD Exchanger in action:
May 22, 2009 No Comments
Why am I interested in viewing and measuring STEP files?Â Because I can make a better automation PCB if I can use STEP files.Â Mechanical engineers, of course, like 3D models they can import and use in assemblies, but I am mainly concerned with PCBs.
There are a variety of standard 3D file formats, including IGES, STEP, 3D PDF, STL, VRML, ACIS, and 3D PDFs.Â The most common formats for electrical components are IGES, STEP, and, recently, 3D PDFs.Â My experience is that STEP files typically import with fewer problems than IGES; 3D PDFs are very nice for viewing parts, but unless the file creator took the proper steps, cannot be used for measuring.
My uses for STEP files include:
- Viewing parts.Â I can’t synthesize 3D parts in my head from a set of 2D drawings, and sometimes it’s very useful to see what a part looks like.Â Â I really like to have real parts to play with, but that’s not always possible.
- Sometimes the manufacturer’s 2D prints do not give all the information I want to create my PCB component shape.Â I can get any dimension I want from a STEP file.
- It’s very easy to screw up PCB connectors.Â Doing a quick assembly of the PCB and components lets me verify that my drill sizes are correct, check for cable orientation, and such.
Since I am not doing any heavy duty mechanical design work, I did a bit of research into free MCAD programs that can view and measure STEP files, and preferably create small assemblies.Â I found one program specifically designed as a STEP file viewer, IDA-STEP.Â Â The free version of IDA-STEP does not measure.
However, most free MCAD programs can import and then measure STEP files.Â I took a quick look at five different programs, listed below.Â CoCreate PE is my favorite of the bunch; it seems the best match for a non-mechanical guy like me.
- CoCreate PE
- Alibre Design Xpress Note: since Alibre has dropped STEP import from Design Xpress, it is no longer a good choice.
- Acrobat 3D PDF
- CAD Exchanger (a program to convert between CAD file formats, but it also works as a viewer)
- CADFaster|QuickStep is another CAD file viewer with free and paid versions; when I get time, I will give it a short test.
Note that the free versions of MCAD programs exist primarily for marketing reasons, and the terms can (and have) changed at any time.
There are other free Mechanical CAD programs that might be able to read STEP files, including:
January 26, 2009 11 Comments
Note 3/15/2012: CoCreate PE has been replaced by Creo Elements/Direct Modeling Express. I haven’t tried it yet.
CoCreate Personal Edition is the free version of the CoCreate CAD program.Â CoCreate PE requires an Internet connection every 3 days, can import IGES, STEP, DWG, and DXF files, export STL and VRML files, and is limited to a maximum of 60 unique parts per assembly.
You can drag and drop STEP files onto CoCreate.Â It has a pretty complete set of pre-defined views.Â Performance on my system is snappy.Â I found measuring easy.Â Hmm, so far pretty short and sweet – that’s because I like it.Â It’s my favorite of the four programs I’ve tried (CoCreate, Alibre, PowerSHAPE, IDA STEP) – it seems the most intuitive to me, and was definitely the easiest to use to measure parts.
Note that like all other free CAD programs, the terms may change in the future.Â For example, PTC (the current owner of CoCreate) had a free CAD program called Pro/Desktop that was later dropped (IIRC, the current users were given a five year license).
January 20, 2009 1 Comment
PowerSHAPE-e is the free version of Delcam’s PowerSHAPE CAD program.Â It has all of the functionality of the PowerSHAPE program, except that you can only save files using the encrypted PowerSHAPE-e file format, which cannot be read by any other CAD software (including PowerSHAPE).Â You can use the Delcam Exchange program to save in another file format; I believe the cost is Â£200 (~$300) per file.
The Exchange software provides CAD file translation for a very large number of CAD file formats.Â Importing the files is free, but exporting to another format costs money (currently Â£34 (~$50) per file for non-PowerSHAPE-e files).Â The Exchange software can be run stand-alone, or from within PowerSHAPE-e.
You can set a variety of import options when directly importing STEP files using Exchange; there are no options when importing using PowerSHAPE-e.Â However, you cannot measure parts in Exchange.
You can drag and drop STEP files onto PowerSHAPE-e.Â One nice feature are all the pre-defined views – just click on the icon to spin the part into that orientation.Â However, I had to look up how to manually rotate a part: you have to hold down the middle mouse button.Â Part manipulation speed is good.
You use the calculator to measure.Â When measuring, PowerSHAPE-e seemed a bit behind where I wanted it to be; it might need a faster system than my Athlon 2800 + older Quadro card
January 15, 2009 1 Comment
Update 6/24/09: Alibre wants to keep Design Xpress secret, and has removed several of the pages linked to below
Update 8/7/09: Alibre has removed STEP file import from Design Xpress, so it’s no longer useful as a STEP file viewer.Â (OK, you can import STEP files during the first 30 days, but after that, you’ll have to pay or find something else).Â Go here for or my latest MCAD news posts.
Alibre Design Xpress is the free version of Alibre Design.Â It is significantly less capable than Alibre Design Standard.Â Limitation include only 5 unique parts per assembly, no advanced modeling tools, and no advanced drawing functions.Â Alibre has a feature comparision here.Â However, Xpress can still do a lot, including create assemblies (many free versions can’t), import and export files in various formats [import DXF, DWG; export STL], be used professionally, and create 3D PDFs.
With the free version of any proprietary software, the terms can change at any time.Â My Design Xpress license allows 25 5 [changed when updated to V11] unique parts per assembly.Â Until recently, the normal Xpress limit was 10 unique parts; now it is 5.
In any case, Design Xpress makes a fine STEP file viewer [for 30 days].Â Â You can drag and drop STEP files onto the Xpress Control Panel (but not a part or assembly window), or use the Import menu or button.Â This brings up the Import dialog box, which controls how the STEP file is imported.
STEP files don’t always import correctly, so it’s good to have these options available.Â Note that these options do affect how quickly the part is imported.
I tested Alibre using the same Norcomp HD26M part; it imported without a problem.Â Â I rotated, panned, and zoomed the part without problems.Â Since I often end up with the part at weird angles, I appreciate the View–>Orient–>To Plane… menu which snaps the part view back to a plane.
I found measuring a little tricky at first, mostly because what I thought I was selecting wasn’t what I really was.Â I was viewing the part looking straight at the front; when I rotated the part a bit (as shown in the picture below), I easily selected the features I wanted.
The Linear/Pairs measurement options takes the first mouse clicks after you select it; I could not figure out how to reset the points being measured without closing and re-opening the measure dialog.Â So I had to be careful where I clicked the first two times.
January 13, 2009 No Comments
The German company LKSoft makes a a free STEP file viewer; the current version is IDA-STEP V4.Â The free version does not allow measuring; measuring, printing, editing, importing, and exporting are extra cost add-on modules.
IDA-STEP is an unusual STEP viewer, because it is written in Java (possibly using the Eclipse RCP), and because it is oriented towards PCB design – just take a look at the available components at the LKSoft store.
I spent a little time playing around with it using the STEP model of the Norcomp 180-026-103 HD26M connector.Â It seemed to work well; rotating the model was fast.Â I wish I could drag & drop STEP models onto IDA-STEP.Â Â As noted, the free version is restricted to viewing; it does not allow measuring.
January 10, 2009 No Comments