Part measuring wrong size in assembly

[NigelHay]

We found during assembly that some parts will not fit together as intended. When we check the Inventor model we find that this part (a simple black ring in the attached image) measures 18.445mm long if measured in the assembly. If I open the part by R.Clicking from the assembly it measures 21.5mm. The part was created by extruding an annulus by 21.5mm. If I insert a 2nd instance of the same part it comes in at 21.5mm, same happens if I copy & paste the part within the assembly.

Can anyone suggest how the part can measure 2 different sizes?

I've included the.ipt here. In the 2 images I've turned off visibility of the parts either side so that nothing obscures it.

We have checked this on the 3 seats of Inventor we have here, same outcome on each PC.

Inventor Pro 2017

Win 7 64 bit

[mcgyvr]

Can you post the assembly?

Are you sure that the section view is not causing this "confusion"..

The part is 21.5..

It looks like you have a section view active.. If sectioned it will measure incorrect..

Disable the section view and measure it again..

[NigelHay]

Thanks for your reply. It still measures the same with the section disabled. I can post the assembly, would I need to use 'pack & go' or would a STEP file be OK?

[CCarreiras]

HI!

If you copy the part inside assembly enviroment, maybe you created a new part... but we only can be sure if you attach here the model or send more info.

[mcgyvr]

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@NigelHay wrote:

Thanks for your reply. It still measures the same with the section disabled. I can post the assembly, would I need to use 'pack & go' or would a STEP file be OK?

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You can simply do a save copy as on the assembly to create a new copy..

Then remove all other parts from it.. Then do a pack and go on that..

Don't provide a step file..actual Inventor files..

It sure still looks like there is a section view there..

[NigelHay · Accepted solution]

No section, the red line you see is just the measurement line, all of the visible parts are on the outside of the ring.  BUT, I've found the problem. I don't know how or why but there is an extrusion in the top level of the assembly, not in the component, which reduces the height of the ring. I spotted it when I made a copy of the assembly & started stripping parts out ready to post here.

Thanks for your attention but this is now solved.