Make components scale issue

[pmaxwellNKJEX]

I am using the 'make components' to export some parts from a multi-solid body.

The part is in inches and scaled wrong, so I'm also using the scale option to correct the part size.

This is where the problem exists.

The part is a wheel, it has a diameter of 6350mm (should be 250mm)

When I scale it by 1/25.4 the resulting part comes out at 247.65mm

I tried 1/25.3 to se what happened and the result was 254mm

It seems this feature is limited to 3 decimal places for accuracy. 

When I use 1/25.4 it rounds to 0.039, when I use 1/25.3 it rounds to 0.040.

Is there a setting somewhere I'm missing, or is this a bug to be fixed by Autodesk?

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Thanks,

Paul.

[admaiora]

Can you attach the part?

[blandb]

I made a circle and extruded it to what you had said, made component and got the same result, but when I opened the part up, and edited the derived part, the scale was set to 0.039 ul, so I then set that to be 1/25.4 and it then came out to be 250mm.

See video:

[cssmyth64]

I know this is not the proper way to do this by any means but.......scale it again? By my math if you take the one that comes out to 254 and scale that by .984 you will be within .07. Quick and dirty.

[pmaxwellNKJEX]

The part I used the 'make components' command on part is very large.

Also the issue is very easy to replicate and not part related.

[pmaxwellNKJEX]

I just tried that and it does work.

So once you're operating in the 'derived part' environment there is no rounding.

It is not a solution though. We shouldn't have to double up on work when it should just work.

[pmaxwellNKJEX]

My workaround for this was to start a new part and then use the 'derive' command, then selected only the bodies I wanted. This works, but is not a solution.

[SBix26]

It may not be quite fair to criticize some techniques as workarounds when the problem is created from the beginning by your use of a major workaround!  The real answer is to go back to the model and make the dimensions right so that no scaling is needed.

But perhaps another way to address  the scaling round-off issue is to set the number of decimal places in your master model and in your part template(s) to a much larger number than three (I believe it goes as high as eight).  Check Document Settings > Unit tab to set decimal precision.

All that said, I agree that this looks like a completely unnecessary limitation (might even fit the definition of a bug).  The number of decimal places displayed in the file should not determine the accuracy of a calculated value like that.

---

Sam B

Inventor Pro 2023.1 | Windows 10 Home 21H2

[johnsonshiue]

Hi! I am wondering how was the part modeled in the first place. On a true-scale 3D modeler, the unit does not change the actual model size. Was it a mesh to begin with? It was probably imported to an inch template so that the model became too big (1 mm became 1 inch).

Many thanks!

[pmaxwellNKJEX]

The model was supplied to us, so the origin is unknown.

Not a mesh, once imported to inventor it was a multibody solid, just non-editable solids.

[pmaxwellNKJEX]

When you're supplied models from external companies, you can't control how the models are made.

Scaling components out like this could be used for a scaled 3D print, but given you could probably deal with an off-scale it's probably not an issue that would arise.

I don't believe this is a setting because the "derive" environment works perfectly with the same input.

As a previous poster showed; if you accept the initial result and then edit it, you go through the "derive" controls and the scaling works.

I'm sure it's a small oversight in the programming, one that will be easily fixed now it has been identified.

[johnsonshiue]

Hi! Could you share the original neutral format file here or send it to me [email protected]? I would like to understand the behavior better.

Many thanks!

[pmaxwellNKJEX]

Have emailed the part to you 

[johnsonshiue]

Hi Paul,

Many thanks for sharing the file with me! Without disclosing the detail of the part, I can share another workflow that can scale the bodies easily besides Derive or Direct Edit.

1) Open the part and set Doc Unit (Tools -> Doc Settings -> Units) to Inch.

2) Export the part as STEP.

3) Start an inch template in AutoCAD.

4) STEPIN -> pick the STEP file.

5) In AutoCAD, type in UNITS and change the length unit to mm.

6) STEPOUT.

7) Import the STEP file back to Inventor.

The bodies will be rescaled from inch to mm.

Many thanks!

[pmaxwellNKJEX]

Hi Johnson,

Will Autodesk be taking this on and increase the number of decimal places that the scale feature will accept during the 'make components' function?

Regards,

Paul.

[johnsonshiue · Accepted solution]

Hi! This behavior is a bit counter intuitive. Actually, the scale factor precision is controlled by the part template used in Make Components dialog. Try this and see if it works better.

1) Open the template ipt file.

2) Go to Tools -> Doc Settings -> Units -> set Linear Dim Display Precision to all decimal places -> Save. Close the template file.

3) Repeat the workflow that you are trying to do.

The scale factor value should stay put.

Many thanks!

[pmaxwellNKJEX]

Hi Johnson,

That did solve the issue with using "Make components"

Why is it that the workflow of "New Part> Derive> Select multibody solid> select solids> Set scale> OK" Isn't affected by the template precision?

Regards,

Paul.

[johnsonshiue]

Hi! I believe the inconsistent behavior is a bug. Make Components dialog should just work like Derive. I will work with the project team to see if we can make it consistent.

Many thanks!

[johnsonshiue]

Hi! This has been confirmed as a defect, INVGEN-63548.

Many thanks!