Hello,

I'm ellaborating a study for my master thesis and I would like to setup a DOE optimization set of analysis but my quality criterion does not fit in the criteria the program has to offer. 

The part I'm trying to study is a small gear with rod and the main criterion I am trying to optimize is the uniform rotation of that same gear so it respects a runout tolerance.

Is there any way I can use the Optimization feature of Moldflow to solve this issue?

Thanks in advance.

Hello, @pdo.rodrigues,

Thank you for posting to the forum!

If we assume that reducing the distortion of gear caused by molding is important for the uniform rotation, you might be able to judge it by using deformation criteria.

Especially, you can monitor dimensional variation at a specific distance by the “critical dimensions”

And by the “roundness”, you can monitor how much a specific rounded edge changes shape due to warp.

The “roundness” optimization criteria are supported in Moldflow 2018.2.

Please see below for the details;

“To create a roundness criterion”

http://help.autodesk.com/view/MFIA/2018/ENU/?guid=GUID-5AF0C51A-7207-485A-9471-49A1D95373E6

“To create a critical dimension for optimization”

http://help.autodesk.com/view/MFIA/2018/ENU/?guid=GUID-C7801E26-31A5-40D6-9536-0CA5BB5E5665#GUID-C7801E26-31A5-40D6-9536-0CA5BB5E5665

Please let me know if you have any questions.

Thanks,

Tetsuya

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Hi @pdo.rodrigues,

Thanks for posting in our forum.

I am not sure what are you trying to achieve with your optimization criteria, but it sounds to me as you want to define a roundness criteria. In that case, since our release 2018.2 we have a flatness and roundness optimization criteria feature that may help you in your project.

I hope it helps!

Cheers,

Javier

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Hello @Javier.Jubierre and @Tetsuya.Ito and thank you for the quick reply.

Warped shaftThe roundness criterion by itself is not enough because even if the gear remains perfectly round, if the rod is warped, it may rotate irregularly. 

So maybe it should be a combination between the straightness  of the shaft and the circularity of the gear. 

Should i apply the flatness criterion to minimize the warpage in the rod by selecting at least 3 nodes? 

As for the critical dimension I cannot see a use for it in this scenario unless there is a way to minimize the variation between two different critical dimension criteria.

So from the tools available, the best solution should be to select at least 3 coplanar nodes on the shaft and establish a flatness criterion in a direction which should be expected warpage. And finally combine the last criterion with the roundness one applied to the gear.

Thanks,

Pedro Rodrigues

Hi @pdo.rodrigues,

Yeah, I agree with you. If you need to analyze the warp on the rod the roundness criteria does not help you much. I also agree that selecting flatness among colinear nodes can make the trick.

Let us know if you succeed with your DoE testing!!

Cheers,

Javier

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