How to change the scale of components and assemblies

[Anonymous]

Hello,
I am trying to change the scale of a distributed project because the 3D printing is going to be in a small scale for testing purposes first. When I am scaling using the scale tool all the bodies are scaling properly but they don't maintain the same position related the each other. So the scale isn't even for the all the parts of the component. I think this is because each bodie is using the same axis in order to scale.
Thanks in advance,
Best regards,
Javier

[jeff_strater]

would it be possible to post or share your design, or at least some details about the design?  The basics seem to work for scaling components, but my test was a very simple case.  There certainly could be problems in model-level scaling.

A couple of questions:

1. when you say "distributed project", are you referring to a design with referenced components stored in different designs, which have been inserted into a top-level design?  The scale command will not act on external designs (they are considered write-only, and need to be edited separately).  So, are you scaling each referenced component independently?  If so, then you are right, that will not preserve positions in the top-level assembly.
2. are you using uniform scale or non-uniform scale?

One thing that might help is to use joints to position components,  Using Joints can help because they will be associative to the geometry,  So, if you have a rigid joint between faces on two different components, and the geometry of the components is scaled, the rigid joint will force the components into the correct positions.

Jeff Strater (Fusion development)

[Anonymous]

Thanks Jeff!

Yes, I forgot to mention that I had to unlink the referenced component before doing the scale operation and select the bodies. Anyway, It could be awesome to allow the possibility to scale referenced components in order to do kitbashing and integrate some cool designs into Fusion 360! 

For this issue, you can use this small document so you can see my problem  http://a360.co/1MLct0p

In this example, I have used a couple of rigid joints (Non as-built joints) and random placements. By the way, I have set the rigid joints with and without offset but I get the same result with both.

The steps I have followed are the following:

 1. Insert the assembly into a document. (since we are not in the same project you probably don't have to unlink the reference)

 2. Select the Scale tool (MODEL mode). Modify -> Scale

 3. Select the component, that means you have to select all the components and bodies inside.

 4. Select the desire Axis. You can use uniform or non-uniform scale type since the result it will be the same.

 5. Set the scale factor (test some random values <> 1) in order to see the result. Each component seems to be scaled but separated to each other.

Tell me if you need anything else! Thanks in advance.

Best Regards,

Javier

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@jeff_strater wrote:

would it be possible to post or share your design, or at least some details about the design?  The basics seem to work for scaling components, but my test was a very simple case.  There certainly could be problems in model-level scaling.

A couple of questions:

1. when you say "distributed project", are you referring to a design with referenced components stored in different designs, which have been inserted into a top-level design?  The scale command will not act on external designs (they are considered write-only, and need to be edited separately).  So, are you scaling each referenced component independently?  If so, then you are right, that will not preserve positions in the top-level assembly.
2. are you using uniform scale or non-uniform scale?

One thing that might help is to use joints to position components,  Using Joints can help because they will be associative to the geometry,  So, if you have a rigid joint between faces on two different components, and the geometry of the components is scaled, the rigid joint will force the components into the correct positions.

Jeff Strater (Fusion development)

---

[jeff_strater · Accepted solution]

well, this was a head-scratcher, all right.  It took me quite a while to figure out what is going on.  It's definitely a bug, and we'll fix it.

the irony here is that the advice I gave you, you actually had followed, but it was also what is at the root of the bug!  Sorry about that.  The problem is that you have applied the scale after the joints.  And, what is happening is that the joints are solving first, then the scale is applied later, which moves the bodies incorrectly.  A workaround can be to put the scale before the joints.

Here is a screencast showing how this works on a very simple case.  At the beginning, I have 3 instances of the same component, all linked together with rigid joints,  If I add the scale afterwards, things fly apart as you have seen.  However, if I reorder the scale to before the joints, everything is ok:

http://autode.sk/1NlRqHf

(sorry, it looks like the "embed" feature in screencast is no longer there, so I can't just embed this inline).

Now, however, that is only part of your problem.  If I do this on your design, it mostly fixes the problem.  However, things are still not quite right.  On further investigation, it seems that there is another bug.  The scale operation is not applied to any offsets in the joints.  I can kinda work around that, by manually editing the offsets, but again you should not have to do that.  Here is another screencast with your sample model, showing the workarounds.  Note that the third component is not constrained by a joint, so I needed to add one at the end:

http://autode.sk/1NlUEdN

It is still not perfect, though.  The screw component is too far down, and I'm not quite sure why.  I think it has to do with the joint origin, but I'm not sure why.

A couple of other notes:

1. you do have to "break link" for a referenced design in order to scale it.  You cannot modify a referenced design from the referencing design today.

2. if you have multiple instances of a component, you really only have to scale one of them.  Selecting more than one has the same effect.  It doesn't do any harm, just FYI.

Hope this helps clear up the issue a bit.  In general, I would recommend doing the scale before the joints.  Or, delete the joints and re-apply them.  Sorry for the inconvenience.

Jeff

[Anonymous]

Really thanks for your answer Jeff!

Yeah, I now about the thing that if you scale the bodies before creating the joints it works good, but you need to do it separately. If you scale multiple bodies at once they will scale using differents local pivots (or axis) and they don't contraist its current position to each other mantaining the same "as-built" position. Anyway, knowing that Fusion has this limitation using the scale tool with multiple objects I will need to take another workaround as you have explained me.

Thanks again

Best Regards,

Javier

[Anonymous]

Is there a way to do this for bodies that aren't connected by joints? A scale from a single point tool? Why does the scale tool have you pick one axis than scale from separate axis' (maybe it's scaling at different rates for different parts?)?

[jeff_strater]

Hi @Anonymous,

I'm not really sure what you are asking.  You can definitely scale multiple bodies at the same time using the scale tool, and they will all scale about the selected point, which will preserve their relative positions.  See the screencast below.  If this is not what you are asking about, can you post a screencast showing the behavior that you think is incorrect today?

Thanks,

Jeff

[Anonymous]

Excuse me pardon my grammar * "pick one axis, then* scale from"


Maybe it's an issue with the imported bodies/components? (It's a cool explosion effect regardless 🙂 )

[Anonymous]

New I should've hit preview first on the screencast....

[Anonymous]

Of course it's insert.

[Anonymous]

I am having the same problem, with bodies not keeping their relative positions to each other when scaled. Was a solution ever found for this? I'm not having any luck searching.

[Anonymous]

Here is a reply I got in another thread:
https://forums.autodesk.com/t5/fusion-360-support/scale-from-point-doesn-t-work-on-imported-stps-etc...

[lichtzeichenanlage]

BTW: If you scale the bodies and tolerances, you'll also scaling your clearances. That's something you should have in mind.

[admaiora]

Is this bug fixed?

[BleysIngram]

I have had similar issues scaling assemblies that have pattern (circular) instances. This is pretty dramatic when reducing things to 1/48th scale. Dissolving the pattern feature helps but I still run into issues that must be from a variety of causes.  Oh, other things that help, make sure all rigid groups are suppressed, un-ground everything, and reset your scale point of origin to 0,0,0,. The point of origin thing gets fairly important with dramatic scale changes.

[sniperstealth]

The issue seems solved scaling from the origin and deselecting random point scaling 

[cnlimpin]

hello, will u please re send the screen cast? i cant open it anymore. I'm currently having the same issue

[cnlimpin]

will u please resend the screencast? its not working anymore. i am having the same problem sir

[lichtzeichenanlage]

The screencast is working for me...