topic Re: Assembly: How to place rotational constraints? in Inventor Forum

Assembly: How to place rotational constraints?

achintya_bhatnagar — Sun, 19 Mar 2023 08:20:19 GMT

I have an assembly of a wheel. I have grounded the central hub. I have few other circular parts that are coaxial with the hub. I was able to align their axes and also prevent their axial movement -- both by placing Mate Mate Assembly Constraints. However, I am unable to make them stop rotating with respect to each other.

I need to align slots in one part with the teeth in the other part, both of which are mounted on the wheel hub, so that all the three parts are rigidly connected with each other.

Could you please suggest how to achieve this?

Attached is my assembly file and a picture. Thank you.

Re: Assembly: How to place rotational constraints?

kacper.suchomski — Sun, 19 Mar 2023 11:48:54 GMT

Use mate/parallel or angular constraints between component work planes to stop mutual rotation.

https://help.autodesk.com/view/INVNTOR/2023/ENU/?guid=GUID-0F500089-4F69-41C5-AFE8-B58AC9E8E15E

https://help.autodesk.com/view/INVNTOR/2023/ENU/?guid=GUID-AD4679FD-EE9B-47C0-9E32-04B990BDD29E

You can also do it all at once using rigid connections.

https://help.autodesk.com/view/INVNTOR/2023/ENU/?guid=GUID-21DC3336-5C51-42C1-90FB-4299CD66E0C6

Re: Assembly: How to place rotational constraints?

Alexander_Chernikov — Sun, 19 Mar 2023 11:49:35 GMT

Unfortunately, the assembly file alone is not enough to open the model - the part files are also needed (it is also advisable to indicate the version in which you are working).

But you can try to use angular constraints between the coordinate planes of each cylindrical part.

Re: Assembly: How to place rotational constraints?

achintya_bhatnagar — Sun, 19 Mar 2023 13:02:28 GMT

@Alexander_Chernikov @kacper.suchomski

I tried using constraints, but adding constraints to link rotation generates errors. See the screenshot here.

I have tried almost everything I could think off. It is still not working. Please see the assembly and part files attached here. I need to not only lock the relative rotational motion but also ensure that the teeth fit into slots.

Re: Assembly: How to place rotational constraints?

kacper.suchomski — Sun, 19 Mar 2023 13:28:16 GMT

The cutouts are rectangular (parallel sides); and the plugs are radial (angled sides). How did you try to align them while maintaining concentricity? (This is a geometry question, not Inventor).
You don't read the advice carefully. @Alexander_Chernikov and I both wrote to use mate/parallel or angular constraints to the construction planes of the individual components, not the faces of the grooves. And after seeing the model, this advice still holds true. And it works.

Re: Assembly: How to place rotational constraints?

achintya_bhatnagar — Sun, 19 Mar 2023 16:15:10 GMT

The rectangular cutouts are arranged in a Circular Pattern along a circle such that the radially outward edges of the cutouts (8.3 mm) is tangential to the circle (using Tangent Constraint in Sketch). The inward edges of the cutouts are 168 mm away from the center of the circle. See the sketch in WheelGeometryTemplate.ipt or below:

Different parts of this sketch (Wheel geometry template) were extruded to make tyre walls, inner lock disk and outer lock disk to ensure that they all align with each other.

The plugs are obtained by Bend Part feature with radius 168.15 mm and angle 360 deg.

This is how while the plugs are curved, the cutouts are rectangular. There is a slight clearance between each cutout and the corresponding plug. Now, in the assembly, I need to ensure that the plugs are inserted into the cutouts and stay there. Note that there are matching cutouts along the circumference of the tyre walls too. They too need to be aligned with the plugs.

Re: Assembly: How to place rotational constraints?

kacper.suchomski — Sun, 19 Mar 2023 16:37:56 GMT

It doesn't change anything. You don't have to explain why you created this geometry.

It's just that the constraint you tried to create is impossible - from a geometric point of view; not because of Inventor.

Create a constraints between the workplanes and after the case.

Re: Assembly: How to place rotational constraints?

89198826955 — Sun, 19 Mar 2023 18:38:43 GMT

You can create construction planes for a single part

and an auxiliary plane to another part

impose dependency on the auxiliary planes

Re: Assembly: How to place rotational constraints?

achintya_bhatnagar — Sun, 19 Mar 2023 20:47:23 GMT

@89198826955 @kacper.suchomski

Could you please be a little more specific how do I create the constraints for my requirements? I am into Inventor for barely a couple of weeks. I see these options here. Which ones should I choose?

Could you elaborate "Create a constraints (which constraints) between the workplanes (what workplanes) and after the case (what case)" and "You can create construction planes for a single part and an auxiliary plane to another part impose dependency on the auxiliary planes (what do you mean by auxiliary planes and imposing dependency on them?)"

Re: Assembly: How to place rotational constraints?

kacper.suchomski — Sun, 19 Mar 2023 21:02:11 GMT

Expand the part files in the browser and select work planes to constrain instead of solid faces in the graphics window.

Re: Assembly: How to place rotational constraints?

89198826955 — Mon, 20 Mar 2023 06:09:15 GMT

make extra

additionally build an axis for the hole

for a rectangle, build an additional plane

combine them

Re: Assembly: How to place rotational constraints?

89198826955 — Mon, 20 Mar 2023 06:16:44 GMT

these are not working planes

these are additional structures

Re: Assembly: How to place rotational constraints?

johnsonshiue — Mon, 20 Mar 2023 21:55:33 GMT

Hi! I think you want to make sure TyreWall4:1, TyreWall4:2, and RollingSurface4:1 rotate synchronously, right? If yes, the constraints to use are Mate or Flush to ensure one of their origin planes are aligned.

Many thanks!

Re: Assembly: How to place rotational constraints?

achintya_bhatnagar — Tue, 21 Mar 2023 07:50:49 GMT

Thank you all for your help. My problem has been solved. In summary, the parts can be locked for rotation in this way:

Place the assembly angle constraint (choose undirected angles) between the workplanes of the parts. For selecting the workplanes, on the left in the browser window, open one of the parts, go to Origin and select one of the planes (XY, YZ or XZ). Then do the same thing again for the other part.

For aligning the plugs with the cutouts, create a new plane as explained by @89198826955 above.

Thank you!