topic Re: How do I assemble these joints together (bushing inside a clamp on a rod)? in Fusion Design, Validate & Document Forum

How do I assemble these joints together (bushing inside a clamp on a rod)?

mgianzero — Thu, 01 Feb 2018 21:40:11 GMT

I've been learning more about assemblies and joints, but can't seem to figure out how to set my two points for a rigid joint when it comes to a bushing clamped by another part like this. I think I can reset my joint origin, but not sure how. When I try to join them, bearing tends to turn on me.

Ideally, I would like the two bearings (LM8UU) butted against each other and fitted snuggly inside my bracket and all placed somewhere in the middle (not end) of the Y Axis rod.

How do I do this?

Re: How do I assemble these joints together (bushing inside a clamp on a rod)?

davebYYPCU — Thu, 01 Feb 2018 22:26:11 GMT

I have made the two bearings, an as built joint, Rigid and kept the spacing you suppled,

then joined them to the carriage block, rigid, the block is not the same diameter as the bearings, so used offsets to position the centre of the bearing with the inferred centre of the channel, and the centre of the bock over the two bearings,

Then made a slider joint for one bearing and the rod,

file attached, edit the joints to see the offset settings to help make sense of it all.

Might help

Re: How do I assemble these joints together (bushing inside a clamp on a rod)?

mgianzero — Fri, 02 Feb 2018 03:33:42 GMT

Dave,

I looked at your file and I think I've figured it out.

Only thing is, I was using linked files (distributed design) and now I cannot edit the joint origins. I read somewhere why this is but I don't fully understand it. https://forums.autodesk.com/t5/fusion-360-design-validate/placing-a-joint-origin-problem/td-p/6029134

Can you join objects using joint origins on linked components?

Re: How do I assemble these joints together (bushing inside a clamp on a rod)?

daniel_lyall — Fri, 02 Feb 2018 04:14:31 GMT

You can not put joint origins on a linked component, you can put the joint origin on the mother of the linked component and edit the joint origin on the mother of the linked component you can not edit the joint origin on the linked component.

If you break the link you can now add a joint origin to said part.

Re: How do I assemble these joints together (bushing inside a clamp on a rod)?

davebYYPCU — Fri, 02 Feb 2018 06:14:44 GMT

Common practise is what @daniel_lyall has said, edit the original component, then you can keep the link,

Can you join objects using joint origins on linked components?

Yes, in the big thread you are discussing, top of page two, was my attempt to explain joints with linked components that don't have Joint origins, included.

Same as Jeff's explanation in the linked thread.

A projected sketch should update if the linked component moves, but I have not tried that.

right now I can't remember if Pete's frame joints were done with linked or unlinked beams, where he used the mid points of face edges, not joint origins, using the contained snapped points avoids the Joint Origin problem all together.

Might help....

Re: How do I assemble these joints together (bushing inside a clamp on a rod)?

TrippyLighting — Fri, 02 Feb 2018 09:16:44 GMT

@mgianzero I personally try to avoid using linked components. There are a number of disadvantages of which one you’ve already came across. They are cumbersome to work with and that really can get in the way of a design workflow.

Re: How do I assemble these joints together (bushing inside a clamp on a rod)?

mgianzero — Fri, 02 Feb 2018 17:31:47 GMT

Hello again Peter. Thanks for jumping in with help.

Would I be opening a can of worms by asking "why it is not good practice to used linked components in a design?"

I think it would be nice to eventually put my model together without linked components as it seems "cleaner" and more organized, at least to me it does. However, if I'm designing parts (or sub assemblies) in such as model as the one I am creating here, I find it nice to edit the individual items in separate files. It also makes it easy for me to test several versions of subassembly parts in the same model.

Re: How do I assemble these joints together (bushing inside a clamp on a rod)?

TrippyLighting — Fri, 02 Feb 2018 23:56:19 GMT

I guess I opened that can myself 😉

In 2016 I was invited to teach a Fusion 360 class at Autodesk University together with Jeff Strater. We prepared a handout for that class and here is a link to a more up-to-date version of it.

It has a section on Linked Components and when they should be used and current limitations, which still exist in that form.

Re: How do I assemble these joints together (bushing inside a clamp on a rod)?

TrippyLighting — Sat, 03 Feb 2018 00:16:29 GMT

@mgianzero wrote:

Dave,

I looked at your file and I think I've figured it out.

Only thing is, I was using linked files (distributed design) and now I cannot edit the joint origins. I read somewhere why this is but I don't fully understand it. https://forums.autodesk.com/t5/fusion-360-design-validate/placing-a-joint-origin-problem/td-p/6029134

Can you join objects using joint origins on linked components?

Explicit joint origins have to belong to a component. However if you are working in a design with linked components, in that design the linked components are static and cannot be edited, so placing a joint origin on. a linked component from the assembly fails. You'll have to open the linked component place the joint origin, save it, Goa back to the assembly and update it. then you can use the joint origin.

However, when working with this red component you will have a problem selecting some of the geometry when trying to place a joint origin. If you try placing a joint origin on normal solid geometry, Fusion will recognize an arc, circle, cylinder etc and will allow you to snap the joint origin to the center of such. This red component is faceted in curved areas and will not allow that. So either you'll have to fix that, or work around it.

Also, if yo can avoid working with such triangulated garbage then you should, I've fixed designs for users where a single component like that substantially slowed Fusion 360 down. Such faceted objects have easily 10-100 times the surfaces they would have if they would be normal solid geometry.

Re: How do I assemble these joints together (bushing inside a clamp on a rod)?

jeff_strater — Tue, 06 Feb 2018 21:15:46 GMT

One small correction to what @TrippyLighting said. You can, in fact, create Joint Origins on linked components. But, it's certainly not obvious that you can do so, or why you can. In fact, I had to try it just now to prove that my memory was not completely shot yet.

What is true is that you cannot make any edits to a linked component without opening that component in a separate tab. So, for instance, you cannot edit a sketch in a linked component from the top level, or even change the visibility of a body in a linked component, because those are edits to that design, and linked components are read-only in the context of the referencing design. We hope one day to change that, but it's how it is today.

And, in all local designs (where all components are defined in one design), when you place a Joint Origin, it is embedded inside of the component that owns the geometry you picked for the Joint Origin. This is, in fact, a violation of the Active Component rule. Normally, any new objects you create go into the active component. So, if you create a sketch or a work plane, it goes into the active component. Joint Origins are the one exception to that rule. Joint Origins are the only objects that can go into a non-active component. So, this combination (linked components are read-only and and Joint Origins always go into the component that owns the geometry you pick) would seem to imply exactly what my friend Peter said.

However... When we were working on linked components, we decided that this workflow was important enough to special-case. So... if you do place a Joint Origin on geometry owned by a linked component, that Joint Origin will be owned by the top-level component in your design. It's a special case to an already-special cased area.

~~OK, that wraps up tonight's episode of "the minutiae of Fusion functionality and history".~~

After going back and investigating further, I will have to recant all of the above. I swore I was able to do this when I tested it, but whatever state I was in I am no longer able to reproduce. So, I apologize for implying that this was possible, and sending folks down the wrong path.

Jeff

Re: How do I assemble these joints together (bushing inside a clamp on a rod)?

TrippyLighting — Sat, 03 Feb 2018 01:30:21 GMT

Ha, awesome!

Re: How do I assemble these joints together (bushing inside a clamp on a rod)?

mgianzero — Sat, 03 Feb 2018 20:04:54 GMT

Jeff and Peter,

These are great explanations to a confusing area of F360 that, I know you have explained in other threads. So thank you for repeating and expanding on this concept.

I'd like to make a few points myself and, perhaps, an additional question or two:

So with this limitation of joint origins not being editable in linked components because linked-components are read-only, is this the reason why it is not recommended to use linked components in general in a F360 model? Peter was telling me this is not good practice. But I liked the idea that I could edit my components in a separate file and not have all the other components, bodies, sketches, etc. to deal with in my current model. So when should someone use linked components and when should they not?

To Peter's comment:

"Also, if yo can avoid working with such triangulated garbage then you should, I've fixed designs for users where a single component like that substantially slowed Fusion 360 down. Such faceted objects have easily 10-100 times the surfaces they would have if they would be normal solid geometry."

Unfortunately, sometimes we get STL or STEP files to work with (I know that's not ideal) but it saves some time on my end redrawing the objects in F360 if I'm not really changing much. This, however, can create these curved or faceted areas which I know can slow down F360 and cause problems down the road. So I only redraw these items when they really become an issue. But, for right now, I simply import the file using the "Insert Mesh Option" and then turn off Design History to go into Direct Modeling and then select "Mesh to BRep" option. I then delete areas where I know multiple planes really describe the same plane to simply the imported component a bit. But I didn't know an easy way to remove the surfaces found around holes, fillets, or curved areas. Did I do this right?

Re: How do I assemble these joints together (bushing inside a clamp on a rod)?

TrippyLighting — Sat, 03 Feb 2018 20:19:58 GMT

I post #8 in this thread I provided a link to the AU handout that Jeff and I created That contains information on when linked components are useful and current limitations.

As it pertains to these triangulated components, if you have access to a dimensioned drawing for that component then I'd "repair" those areas on such a component that have to fit to tother components. In this case the cylindrical surface for the linear bearings. Then you can joint these correctly.

Re: How do I assemble these joints together (bushing inside a clamp on a rod)?

mgianzero — Sat, 03 Feb 2018 21:22:20 GMT

Peter,

"As it pertains to these triangulated components, if you have access to a dimensioned drawing for that component then I'd "repair" those areas on such a component that have to fit to tother components. In this case the cylindrical surface for the linear bearings. Then you can joint these correctly."

Maybe I'm not following here, but I often times do NOT have access to the dimensioned drawing for many of these components but STEP or STL files (I know they are not ideal) are all I can get my hands on. Often times I either reuse the same parts (designed by another CAD program) or use with minor modifications. So redrawing ends up being a bit of extra work. Is there a relatively easy way to modify these converted STL file's without redrawing the whole part, as you mentioned the cylindrical surface for the linear bearings looks sloppy. I am aware of this, but if I have fifteen of these similar parts in about 8 different printer models, I'd be doing lots of extra editing I didn't think was necessary. As it is right now, those STL files are working models that can easily be printed as is using a 3D printer. I didn't want to redraw everything when really fitment, and possibly animation, are all I'm really considering here.

I did read your handout (very nicely written) regarding the need for linked components it said:

When are linked components needed ?

When the component/assembly is to be reused in another design AND
Modifications to it are expected.

In my situation, we are designing several different printer models and each will most likely use some of the same components (option #1 above) and since we are also simultaneously modeling several printers at the same time, minor adjustments to the build volume of any of these printers may require an alteration to the design of these parts (option #2). Also, we may want to go back and forth between a different set of component modifications to study their differences and may even use two set of parts as options on the same printer. So if we follow your handout, linked components seems like the way to go.

I just seems to me that editing joint origins is my biggest hangup with using linked parts in my scenario. Not trying to be difficult here, just trying to understand the limitations of using F360 in this capacity.

Re: How do I assemble these joints together (bushing inside a clamp on a rod)?

TrippyLighting — Sat, 03 Feb 2018 21:34:53 GMT

These .stl comports are OK to work with, they can be a hassle simply because the joints in Fusion 360 don't provide meaningful snap points for assembly, but then you can locate a joint origin and just offset it to the desired location. Not ideal, but you only have to do that once, so it's an alternative for these components.

The scenario you are describing is one where I'd use a linked component as well.

Re: How do I assemble these joints together (bushing inside a clamp on a rod)?

Anonymous — Tue, 06 Feb 2018 17:49:41 GMT

@jeff_strater wrote:
You can, in fact, create Joint Origins on linked components.

@jeff_strater

How?

When I try "Joint Origin" on a linked component, I cannot select any geometry of that component.

Manfred

Re: How do I assemble these joints together (bushing inside a clamp on a rod)?

mgianzero — Tue, 06 Feb 2018 17:56:26 GMT

Manfred,

What I ended up doing since I really wanted to keep the linked components was I simply opened up and edited the original linked files and selected "joint origin" from there. When you save these files and then update your assembly file, you will see the joint origin there to create a joint with.

Re: How do I assemble these joints together (bushing inside a clamp on a rod)?

Anonymous — Tue, 06 Feb 2018 18:25:50 GMT

Ok, sorry, the confusion was caused by my bad English.

I did not realize that "create Joint Origins on linked components" means "open linked component and then create the joint origin". That procedure of course works for me too.

@TrippyLightingfalls Du mal Zeit für Nachhilfe hast: wieso bedeutet "on" sowohl "auf", "an", "bei" - aber auch "in" (laut dictionary). Und wie erkenne ich, daß Jeff mit "on" meint, daß man "in" der component den joint erzeugt und nicht "auf" der referenz? Seufz....

Re: How do I assemble these joints together (bushing inside a clamp on a rod)?

TrippyLighting — Tue, 06 Feb 2018 18:35:55 GMT

No, the confusion is cause by @jeff_strater explanation, which suggests that if you have a linked component in a design, that you can still create a joint origin associated with it's origin in that very design.

What is different to a joint origin for an "embedded" component is that it won't be part of that linked component but will show up in the joints folder at the top level.

However, I don't know how to create that sort of a joint origin, because as you described, you aren't offered any snap points on a linked component.

Of course you can always open a linked component, add the joint origin, save it, go back to the assembly design and update it.

Re: How do I assemble these joints together (bushing inside a clamp on a rod)?

jeff_strater — Tue, 06 Feb 2018 19:30:47 GMT

Hmm... I swear I was able to do this when I posted that. But, now I see the same thing - unable to select faces on linked components. I apologize, and I'll dig into this further to see if my original statement was completely wrong, or if there is some workflow where this works.