Learning About Assemblies

It’s one thing to know about a topic intellectually. It’s another thing altogether to have some hands-on experience with it. This week I’ve spent in training with Solid Edge. It’s entirely humbling, I have to say. Being an expert in one tool does not automatically make you an expert in another. I’ve long acknowledged my SE noob status. But all that experience doesn’t mean it’s even going to be easy to learn another tool. I had to go through the same process as the rest of the students to get the hang of how things work, and how to navigate.

Let’s take a look at a few topics we learned about in class:

Mates in SE

There are two different sets of tools that look similar. There are the tools on the Relate group, and the tools on the Face Relate group. Face Relate are relations that position or orient faces, changing the shape of a part. The Relate group are tools that position or orient parts, like mates. There is another Ribbon group in the part environment called Relate which is just a set of sketch relations.

mate – face to face coincident
planar align – can be at a 0 distance or at a specified distance, which would seem to be parallel, but that’s a different relation. This applies to faces
insert – This appears to be a combination of a concentric and planar – like the hinge mate in SW
connect – This appears to be a point-to-point coincident, but can be point-to-line, or point-to-face.
axial align –  basically concentric
parallel – Can be parallel at a specific distance or an unspecified distance, but this is applied to  edges
angle – what it sounds like


Solid Edge also has mates like Cam, Gear, Center plane, Match Coordinate Systems, Rigid Set, and Ground, all of which have equivalents in SW.

The way some of the training is set up, it appears to walk you through the bad section of town first. There is actually an option called “Use Reduced Steps When Placing Parts”. The training has you do stuff like pick a part to be mated. Pick a face to mate. Confirm the selection. Pick the other part. Pick the other face. Confirm that selection. That’s 3X the number of picks you really need. And then later, they tell you to use the “Reduced Steps” option, which I think eliminates the need to identify the part. And then they pull out the “FlashFit” thing on you. So the training actually makes the software look bad, then better, then great. I would have made that order the other way. So you see that the fast workflow is there, which makes you feel good about the software, and then show you there are other ways to do it (and associated benefits of the more detailed workflow, if any).

FlashFit is great. You just pick faces, and the parts fly together. No Vulcan mind-meld grip on the mouse or keyboard when you’re doing it. Pick, pick, slam. Pick, pick, slam. It works. Why the training tortures you first, then shows you FlashFit just seems unnecessary. Maybe you do need to know all those arcane picks. But first of all, make the “Reduced Steps” option the default. Not sure if its ever really necessary. The student’s experience with the software should be positive. FlashFit is probably most comparable to SmartMates in SW, except that you don’t have to Alt-drag. Alt-drag is difficult on two levels. First, holding down Alt and knowing when to drop it, especially when used with Tab to flip a mate (Alt-Tab is the shortcut to change windows), and second dragging something specific to something specific, and knowing when to drop the mouse button as opposed to the Alt key. It is much easier just to click on stuff without dragging, and without holding down modifiers. So FlashFit beats SmartMates by a mile in the usability category. I think it’s limited in the same way that SmartMates are limited – essentially coincident and concentric mates, which are probably most of your mates anyway.

Getting used to the terminology and differences in function will take putting together a few assemblies to get comfortable with, but so far it looks good. Oh, also, the Ground mate in SE is actually a mate, while in SW, Fixed is not a mate. This always confused me. SE’s method here makes more sense.

If you use patterns in Synchronous parts, the patterns should be applied as procedural features so that they can help in placing parts in the assembly. SE has the functionality to allow feature patterns to drive component patterns.

0013Replacing Parts in Assembly

Our trainer never went through it, but ST5 added some great functionality around replacing parts in an assembly. None of this nonsense that you have in SW with file names and conflicts. You can replace a part with a copy of itself, which you make on the fly. You can also replace a part with a brand new part. SW is annoying in this respect, but as a user, not knowing anything else, you just accept the limitation, and use the weak tools as they are, instinctively working around flaws. Ive seen these SE tools demoed by Art Patrick, who just makes the software sing. Strongly recommend his sessions at Solid Edge University.


Inter-part relations are like in-context stuff in SW. Personally, I’m not sure that I’d use inter-part, but not because it’s a bad tool. I think it makes more sense than SW’s in-context, because it actually places surface copies of the other part within the part with the relation. Also, it is really clear about what you are doing – making a relationship where one part drives another. In SW, it’s all very vague, so people tend to get themselves in trouble quite often with in-context, because you might do it never knowing what you’ve done. In SE at least you have to make the conscious decision to drive one part with another. SE appears to give you better control, or at least fewer repercussions if you screw up.

You can create persistent relationships between faces within a single part, but not between parts in an assembly. So Synchronous assembly editing should rely on Live Rules. Ordered assembly editing can include inter-part relationships.

The whole deal about reference bodies in SE is very different from SW. In SE, the inter-part reference body is a surface body. So SE users are actually using surfacing more often that SW users. And they are using them automatically in a way that SW users often set up manually, and pat ourselves on the back for doing it. I haven’t tried to break it yet, but inter-part looks more robust than in-context. Especially on the file management side, which I’ll have to come back to another time.


The main reason I don’t think I’d use inter-part in SE is because I’d probably use Synchronous in assemblies instead. Synch assemblies are brilliant. You just manipulate parts by moving faces, and you can use faces from other parts as references, without creating permanent relations. It’s the ability to use parts in assembly as reference without the nasty overhead of external references. It’s the whole “create the design intent when you need it” sort of thing. Synch assemblies is a topic all its own. Again, refer to Art Patrick for this kind of stuff.

0015Assembly Explode

To me, the assembly explode interface in SE is really awful. There are far more picks than necessary. It just looks old, and like no one has gone through it in a while. Granted, Explode isn’t the most commonly used feature, but it should get a make over. Not just the way it looks, but the way it works. Pick the part(s), move it. I know those guys can come up with good interfaces, it’s just a matter of getting to it, I’m sure. Separating Explode from the rest of the assembly functions seems a little odd to me. It is in the ERA (Explode, Render, Animate) area.

Inserting Parts into the Assembly0017

I’ve always thought that the SolidWorks interface for Insert Component has some unnecessary steps. I think it has to do with the Browse button being a separate step. It should just go into that directly. Anyway, I don’t get that feeling in SE. The Parts Library window is very convenient, and has sorting and search tools. The little display at the bottom of the Parts Library window is active – you can rotate that part, and the part will come into your assembly in the displayed orientation. This is really nice. Your spaceball will even drive it. This really helps pre-assemble parts, to put then in so they can be mated correctly more quickly.

Speaking of spaceballs, your spaceball will also rotate individual parts in the assembly, just like SolidWorks.

Other Interface Bits

There were other parts of the SE assemblies interface that didn’t seem up to par with the rest of the software. The display configurations seemed a little clunky. Display configurations are like Display States in SW.

The Prompt Bar is a huge helper in SE, if you can remember to use it. In most workflows the Prompt Bar will tell you what SE is looking for next. This is really necessary, since SE doesn’t have list boxes for selections the way SW does. In SW, if the software is looking for something, there is an empty selection box. In SE, the selection is all visual, and the prompt is text based. I’ve said it before, and after training, it seems even clearer – the SE interface is fairly cryptic. It might be the lack of selection boxes that makes it seem this way to me. In the Command Bar shown above or to the left, you see the interface for Auto Explode. The lack of listing selected items in a selection box is a decided difference between SE and SW.

This relates to my main difficulty with the SE interface overall, that it is very icon based. I’ve described before that this is great for expert users, but for learning, it’s tough. Most of the time in class, I turned on the setting at App Menu=>SEOptions=>Helpers=>Command User Interface=>Use Vertical Docking Window Form. But sometimes I just couldn’t find it in this format (talking about the Command Bar here).

There’s a bit of terminology that you have to get past, as a SW user. In SE, “activated” or “inactive” are like “resolved” and “lightweight”. In SW, the terminology has an inherent confusion about it, where the opposite of suppressed is resolved, but the action to do that is unsuppress. Also, the opposite of lightweight is also the opposite of suppressed. So SW has this three-state cycle where SE just has two two state cycles (show/hide, active/inactive). I thought SE had some equivalent to suppressed, but I don’t know what it is.


Overall, SE assemblies are very good, but there are areas where the interface and workflow need updated. The visuals are pretty good, meaning that SE makes good use of transparency and color to help you understand where the focus is and what’s currently selected. The prompt bar is your friend. Hotkeys in SE are very efficient, and once you’re familiar with them, I think even more productive than they are in SW. They got all the big areas right, I think.

Having taken the basic class, I’m now dangerous enough to teach myself the more involved aspects, and maybe more than that I know how to ask the right questions. It took me 17 years to get where I am with SolidWorks, and I expect working with Solid Edge will be a process as well. But overall, SE is much more to-the-point than SW. There are fewer irrelevant bits. I can’t even imagine trying to learn SolidWorks from the ground up today. You’d have to ignore 90% of the software because it doesn’t even relate to basic CAD.

I’m very grateful for the chance to take this training. The on-line component worked out really well for the most part. You have to be disciplined to get the most out of it, but you just can’t beat the convenience.

Updated: March 16, 2013 — 6:17 pm


Add a Comment
  1. Matt relate to assembly relationships, here some concept that might  interested you.It might speak to you more, now that you have some hands on experience with the software. The way icon are create ( the triangle represent the normal of the surface) it help you picture how the constraint works, especially if you run in manual mode versus flash fit.

    Once the constraint is placed , the icon give you a better visual feedback.

    It date back few years ago ( 2-3) but the concept is still the same


    Relate to the article is a series of video here the first one,  The other should be available from the top of the screen.


    Not sure you had time to play with it, the Relationship Assistant, I’m sure your dangerous side will want to look at it :-)

  2. Matt, the Mate and the Planar Align relationships are very similar to each other and work the same way meaning both can make the faces coincident, some specified distance apart or floating.  What makes them unique is that Mate is for aligning the exterior face normals such that they are pointing towards one another and Planar Align points them in the same direction.

    Hope that helps.

  3.  Thanks Matt for sharing your experience and I agree with most of the points you raised. Regarding inserting parts into the assembly, I really would like to be able to drag a particular part from the little display window at the bottom directly to the assembly instead of going back to the part library and dragging the file from there. This added option will save time, unnecessary mouse movements and clicks.

  4. Hadi

    I would propose to:

    – Select the part from the library
    – Drag the component
    – select a surface that will participate in the part placement
    – Press and maintain the CTRL key and pivot the part to the orientation that best fit your needs.

    If you simply click and drag, the part will be pan

    If the surface you select is not the one you need, RMB to unselected and click a new one

    So now you won’t have the unnecessary mouse movement and you will save 150 pixel in travel ;-)



  5. Matt,

    I don’t know if you came across it, but there is one other little gem in FlashFit – if you pick two circular edges, if possible it will create both a mate and axial align with locked rotation. So for something like placing a bolt into a hole, you can fully position the part with two clicks.

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