looking for technique - join components and create bolt holes

[chmed]

I have two "rails" that I want to bolt together.  One has a pattern of bolt holes already and I want to use it as a guide to create corresponding holes in the 2nd component.  I have added each component to a new design and joined the appropriate faces such that they are centered to each other.  But, one rail needs to be located closer to the edge of the other rail.  I have't found any way to join the 2 pieces in the correct position without creating holes or other geometry on the rail with no holes.  

For this particular situation it would probably be faster to just layout the holes on the bare rail but I'd like to learn some techniques for doing this as I expect that I will need to do this kind of thing in the future.  

Any suggestions?  Perhaps there is something that I've missed about the join function?  

[jeff_strater]

Hi @chmed, I think I get the gist of your request.

I'm not sure what your rails look like, so I'll just use a couple of flat plates.  The key, here, is to use Joint Origins.  This will let you offset the joint by a specific amount.

Here is a screencast.  Hopefully you will get the idea of how to apply this to your own designs:

Jeff

[Anonymous]

Neat! Something new every day, right? 🙂

[chmed]

Thanks, this is just what I was looking for.  

Except that there are 2 problems I'm having:

A)  If there are 2 of the same component inserted into a design, only one of them seems to be able to accept a joint origin.  

B)  I've been making basic building block components in their own designs and inserting them into my master design.  But, it seems that I have to unlink these components in order to cut holes in them.  This means that I can't go back and modify a component from its own design and have it update in my master design automatically.  It seems like there should be a different way to do this.  I don't really want to create all of my components in my master design, it might get pretty slow and cluttered.  Am I missing something?  

[jeff_strater]

Hi @chmed,

If you are using inserted components, then the process for the Joint Origin is slightly different.  And, you will run into a problem when you want to cut the holes.

But, first, backing up a bit:  Do you really need to use inserted components?  It's fine if you do, but one of the advantages of Fusion, in my view, is the ability to define local components, without having to create separate designs for each.  As @TrippyLighting likes to say:  don't use external components unless there is a really good reason to do so.  Mostly, that reason is:  You want to share the components across multiple designs.  If a component is only used in one design, I would keep it as a local component.  There is really no performance concerns with local components, as far as I know.  Using external components is inherently a "bottom-up" design process.

However, if you do want to use external components:  You will have to open the external design, and insert the Joint Origin there, then go back and update your design to see the Joint Origin.  But, this is where the process falls down:  You are correct - you cannot cut holes in an external component, from the top level.  You would have to open that component, and cut the holes there.  But, then, you would lose the ability to use the first component to properly align the holes.

It really comes down to whether you want to do "bottom-up" modeling, in which case you design components in isolation from each other and assemble them, or "top-down" modeling, in which case local components make things easier on you.

Sorry this doesn't really give you the answer you wanted...

Jeff

[TrippyLighting]

So what made you believe that that is a good approach ? I know this sounds aggressive maybe even provocative, but I really don't mean it that way!

Quite a few users do this and I am wondering where this comes from.

This is really not so dissimilar from my own experience in starting with Fusion 360. I was convinced that external components (or XREFs or Block, or linked components) are an absolute necessity. This was mostly based on working with two other solid modeling software solutions, namely Solid Works for 12 years and Geomagic Design for 4 years. Both of these softwares use a different file format for assembly files and for component files.

I is fairly normal for veteran CAD users to work in Fusion 360 with way too many external components. However, it appears that also a good number of user without prior CAD knowledge also seem to do this and I am very curious as to what the root cause for this is.

As Jeff has stated, one very distinct advantage is that Fusion 360 does not differentiate between a component and assembly file. You can perfectly fine design fairly complex designs with many components in a single file. I am assuming these are your first designs in Fusion 360 and my advice would be to not use linked components at this time and this early in your design process..

Once a component is finished in one particular design its fine to be exported into it's own file if you want to use it in another design. But starting with unfinished components in separate files that are linked to one master file and then will need many edits and design revisions will definitely slow your design process one and make it cumbersome and rather frustrating.

[chmed]

Thanks for the input guys!  

To address some of the comments, I am fairly new to Fusion 360 but I'm really liking it.  I took some AutoCAD way back in college and I've used a few basic CAD packages for the past few years to do a variety of CNC projects (even got somewhat proficient with Sketchup) but with F360 I finally feel like I have the right tool.  So far I've modeled a few things and I've written some CNC toolpaths.  Although I hit some bumps with post processing and trying to feed the old CNC router, I'm very excited about what I can do with this CAM.  

In this case, I was creating basic aluminum and steel profiles as separate components since I figured I would want to pull them into designs for various purposes without having to recreate them every time.  That said, I had the idea that I would maybe apply some features specific to my current project into some of the of components.  I have been experimenting with the sim functions and wanted to swap beams around quickly so I was looking for a way to keep my reference mounting/alignment holes in the components.  But I wasn't really sure how to approach it.  You know, just stepping into the dark room and feeling around for the right light switches.  In light of the largely one-way cross referencing system between components it makes sense to me now to just keep these profiles as components and unlink them when I place them in a design.  And that's probably fine.  For every tool there is a process or workflow that is best avoided.  And I can export the components if there are features I really want to "save".  

The sim side has been very cool so far.  Initially I was looking at basic deflection calculators and searching the web for moment of inertia specs for various profiles but with F360 I can do a lot more than that.  It's even in color!  

To answer your question about why so many people want to design using separate components... I think it might largely be a mental clarity thing.  If we build in small blocks or increments then it is easier to keep the thoughts and work space uncluttered.  We need to "compartmentalize". In some ways the human mind is astounding and in other ways it's incredibly limited.  

[TrippyLighting]

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@chmed wrote:

To answer your question about why so many people want to design using separate components... I think it might largely be a mental clarity thing.  If we build in small blocks or increments then it is easier to keep the thoughts and work space uncluttered.  We need to "compartmentalize". In some ways the human mind is astounding and in other ways it's incredibly limited.  

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Yes, that makes good sense. At the current time, using external components keeps things very separate, fr example you cannot. say project an outline from existing other components to you linked component and use that projected sketch to modify the linked component.

The advantage of Fusion 360's all in one file approach is, however, that you can keep things separate if you need to but it won't limit you when you don't want to.

The one way that's right for most applications to create "good" internal components is to follow Fusion 360 R.U.L.E #1: 

Before doing anything, create a component and make sure it's activated.  

This will do several things:

1. All objects created after activation such as sketches, bodies, construction planes, joint origins, etc.  are created in that component.
2. When the component is exported to it's own file in the data panel with "Save as", perhaps for re-use in in another design, it will contain the parametric design history and all these objects that were created to make the component.
3. The design history also called timeline will become increasingly unwieldy in larger designs. Activating a component fill filter the timeline for only those items that pertain to that component, which makes the timeline much easier to deal with.