topic MOTION ON A FLIGHT PATH in Inventor Forum

MOTION ON A FLIGHT PATH

a.amirNVP3B — Tue, 04 Mar 2025 09:07:23 GMT

Hi all,

can anyone help me to constraint the scraper onto the flight. The scraper has a pivoting point at the top. I really need to know whether the scraper my clash in between the shells. The

Please find attached the screenshots.

THANKS IN ADVANCE.

Re: MOTION ON A FLIGHT PATH

Michiel.Valcke — Tue, 04 Mar 2025 09:54:43 GMT

Have you tried placing a transitional surface constrain?
https://help.autodesk.com/view/INVNTOR/2025/ENU/?guid=GUID-CD8AE8A0-03F0-468A-BE85-D7C5B989BA0B

Re: MOTION ON A FLIGHT PATH

a.amirNVP3B — Tue, 04 Mar 2025 10:44:42 GMT

I tried but it did not work.

Thanks,

Anas.

Re: MOTION ON A FLIGHT PATH

JDMather — Tue, 04 Mar 2025 11:57:26 GMT

@a.amirNVP3B

I would use Environments>Dynamic Simulation for this analysis.

Re: MOTION ON A FLIGHT PATH

Michiel.Valcke — Tue, 04 Mar 2025 13:26:25 GMT

Does your joint have enough freedom to compensate for the lateral move of your scraper?

Re: MOTION ON A FLIGHT PATH

johnsonshiue — Tue, 04 Mar 2025 20:30:34 GMT

Hi! I believe Transition Constraint should work as long as you limit the transition scope using a surface body. Please share the files here.

Many thanks!

Re: MOTION ON A FLIGHT PATH

a.amirNVP3B — Wed, 05 Mar 2025 06:04:15 GMT

Here is the model.

I tried Environments>Dynamic Simulation to do the analysis, I did not find a solution yet.

Re: MOTION ON A FLIGHT PATH

johnsonshiue — Wed, 05 Mar 2025 20:50:45 GMT

Hi! The iam file isn't enough. Please use Pack&Go to ensure reference all files are included in a folder. Zip them and attach it here.

Many thanks!

Re: MOTION ON A FLIGHT PATH

a.amirNVP3B — Thu, 06 Mar 2025 06:13:06 GMT

hi, sorry 😅.

here is the pack&go file.

Thanks.

Re: MOTION ON A FLIGHT PATH

johnsonshiue — Thu, 06 Mar 2025 21:21:58 GMT

Hi! Many thanks for sharing the files! I took a quick look. Indeed, there is already a surface body in the sheet metal part. However, Transitional constraint (and all other assembly constraints) work between two different components. The transition will only happen between two selected components.

In your case, you will need to have one part with all of the loft surfaces combined together. Then the scrapper transits on the combined surface bodies.

You could easily do that by saving the current assembly as a different assembly. Next derive the new assembly to a part (include only the surface bodies). Then use Stitch command to combine all surfaces into one quilt. Place the derived part into the old assembly. Add the transitional constraint between the scrapper and the quilt surface. It should work.

Thanks again!

Re: MOTION ON A FLIGHT PATH

a.amirNVP3B — Tue, 11 Mar 2025 05:52:00 GMT

Hi, I tried what you proposed, it should work logically but I get the error window ("The assembly cannot be solved").

I tried to reduce the scraper arm's length for it to fit in the locus of the path, but it gives the error window and when I accept the relationship the shaft does not rotate nor the scraper swings.

If I send you the files I modified, would you be able to try and see if it works?

Thanks.

Re: MOTION ON A FLIGHT PATH

JDMather — Tue, 11 Mar 2025 13:28:20 GMT

@a.amirNVP3B

I do not own a license to a rar extractor.

Can you Attach *.zip file instead?

Re: MOTION ON A FLIGHT PATH

johnsonshiue — Tue, 11 Mar 2025 20:55:08 GMT

Hi! Yes, absolutely! Please share it here or send it to me directly (johnson.shiue@autodesk.com). I would like to understand the failure better.

Many thanks!

Re: MOTION ON A FLIGHT PATH

a.amirNVP3B — Fri, 14 Mar 2025 08:33:53 GMT

Hi Mr Johnson,

sorry for this late reply. I will send you my model in a bit.

I worked on a solution but I need to add a constraint to the scraper so that it stays within the two shells where the path is. instead of having fixed hanger the support, I made the point of support a pivoting point so that each time the scraper comes to contact with the shell, it rotates so that it continues its way. I cannot figure out the right constraint to use, while I constraint the end part of the scraper tangentially to the shell it does not work.

Find attached a video of the solution I am working on.

If you could suggest something I would be grateful. Thanks.

Re: MOTION ON A FLIGHT PATH

a.amirNVP3B — Fri, 14 Mar 2025 08:35:29 GMT

Hi, I could not save *.zip. Can I have your email please? I will send you the files directly.

Thanks,

Anas.

Re: MOTION ON A FLIGHT PATH

johnsonshiue — Fri, 14 Mar 2025 19:51:11 GMT

Hi Anas,

Many thanks for sharing the files! I took a quick look and modified the model a little bit. It should work better now.

Without disclosing the design detail, I can share some comments regarding this issue. It is a combination of Tangent constraint and Transitional constraint leading to reduced DOF. To make Transitional constraint work, it is better limit the scope of transition. Use a small sphere or a surface to transit over the target face.

Tangent constraints can be replaced by Mate constraints or Flush constraints whenever it is applicable. Tangent constraints are better used when the components are not connected to other components. Otherwise, the DOF can be significantly reduced.

Thanks again!