topic Re: A constrain issue in Inventor Forum

A constrain issue

Anonymous — Tue, 15 Sep 2020 13:53:03 GMT

Hello everybody,

As you see in the attachment I have encountered a problem in Tangent constraining the Blue Tube to the Red Strap where I did many attempts to do that but no success. Would you please help me to do that even if it is necessary to redesign the Red Strap?

Thank you,

atajabbas

Inventor 2017

Re: A constrain issue

imajar — Tue, 15 Sep 2020 15:02:28 GMT

Hi @Anonymous , I opened the assembly, but don't see any issues with tangent constraints. Nor do I see a blue tube. Do you mean the green tube? Can you take some screenshots and sketch what you are trying to do?

Re: A constrain issue

mcgyvr — Tue, 15 Sep 2020 15:30:07 GMT

You can constrain the surface of the green tube to an "edge" of the red strap using a tangent constraint but you can't constrain to a "face" of the red strap using tangent as thats just not physically possible do to the other constraints you have applied to the green bar.

Re: A constrain issue

Anonymous — Tue, 15 Sep 2020 19:59:21 GMT

Sir,

Many thanks for your reply

In the new attached files and in the assembly I have constrained the Green Tube as Tangent to the Shade Tube just to show you, but what I want is to let the green Tube to lay as a tangent to the Red Strap even if to change the shape of the strap itself. I know the green tube is in an angle to the strap and this what I do not know how to handle it or how to measure the angle

Thank you

atajabbas

Re: A constrain issue

imajar — Tue, 15 Sep 2020 20:59:50 GMT

I'm still not sure what you are asking. Do you want to bolt the green tube to the red plate?

Would you rather keep hole in the shade tube where it is and bend the red plate to match the angle of the green tube, or would you rather keep the red plate straight and drill the hole in the tube at an angle?

Re: A constrain issue

johnsonshiue — Tue, 15 Sep 2020 21:58:38 GMT

Hi! I took a quick look at the assembly. If I were you, I would avoid using Tangent constraints. Though the spacial relationship in real world for these rods may be tangent, I believe you would be better off using Mate or Flush. The issue with Tangent constraint is that it can be unstable in terms of the solve result. The solutions may not be unique.

Many thanks!

Re: A constrain issue

Anonymous — Wed, 16 Sep 2020 14:49:23 GMT

Hello Mr. Aaron Jarrett, PE, the nice man.

Many thanks for your kind reply.

Indeed I now have divided the Red Plate into 2 parts and I did the assembly again as in the <attachement> to show you the action that I want. And yes, I want to bolt and bent the Red Plate to along the Green Bar. But first, we should know the angle between the Green Bar and the Red Plate and then how to bent it to tangent the Green Bar. I added another parts for clarification my idea

Many thanks

Re: A constrain issue

imajar — Wed, 16 Sep 2020 15:20:27 GMT

OK, I will send you two private screencasts in a minute showing what I am about to describe:

In this new assembly, you don't even need to know the angle, you can use constraints to do everything automatically, see the screencast. BUT, this assembly is more expensive to make.

A much simpler method would be to bend a plate, the second screencast I'll send you shows a crude way to do this.

Re: A constrain issue

Anonymous — Wed, 16 Sep 2020 18:33:52 GMT

Yes, sir, the assembly is to show what I want and what I encounter

You are right, it is better to bend the plate. but how

Many thanks

atajabbas

Re: A constrain issue

imajar — Wed, 16 Sep 2020 18:36:21 GMT

You should have received a link to a second video showing how to bend the part. If you didnt, then google search the "fold" function in a sheet metal part.

Re: A constrain issue

Anonymous — Wed, 16 Sep 2020 22:07:48 GMT

Sir,

Many thanks for your reply

Indeed I haven't received any link for both neither "fold" has been not found in google

Thank you

atajabbas

Re: A constrain issue

imajar — Wed, 16 Sep 2020 23:10:03 GMT

Thats odd. All of the results on the first page of google show how to do it when you search for "Inventor Fold".

If you cant find anything, then just take the tutorials on making sheet metal parts, that will teach you how to do it.

Here are public links to the videos.

https://autode.sk/2ZKsWlf

https://autode.sk/35DWDIF

Re: A constrain issue

Anonymous — Thu, 17 Sep 2020 14:31:47 GMT

Thank you so much for your reply

Indeed I searched for Fold only and not for Inventor Fold. Maybe this is my error

Thank you for the links and they are very helpful

atajabbas

Inventor 2017

Re: A constrain issue

Anonymous — Fri, 18 Sep 2020 20:13:19 GMT

Hi Mr. Aaron Jarrett.

I have followed the instruction in the video for Bent Part, but I couldn't succeed. The attachments are shots of what I see. Would you please tell me where is my error?

Thank you

atajabbas

Inventor 2017

Re: A constrain issue

imajar — Fri, 18 Sep 2020 20:27:20 GMT

I cant tell what you have selected in the second picture. But if you tried to select the front face of the bent plate and the outer surface of the pipe, it wont work. To get it to work, the software will need the two to be perfectly parallel and the method I used only get it parallel to .001 degrees. (or whatever precision you used) Instead, you can place a tangent constraint between the face of the bent plate and the top edge of the tube (a circle).

Re: A constrain issue

Anonymous — Sat, 19 Sep 2020 14:04:01 GMT

Hi Mr. Aaron Jarrett, you are so nice.

I have done it by doing the Tangent constrain to the Bending Line and it has been succeeded

Indeed, unexpected to use the bending line instead of the surface.

Beautifull solution

Thank you so much

atajabbas

A tangent problem

Anonymous — Sun, 18 Oct 2020 09:43:14 GMT

Hi Mr. Aaron Jarrett

Would you please take a look to the attached assembly file.

My problem is how to let the Blue Plate to be tangent to the Green part.. By calculations , I can do it very close to the green part but my need is Tangent to the green part. There is freedom to make changes to the Blue part to suit or to solve the problem. If we can do double fold to let the blue part shorter , it will be better and the strength of the jount will be better.

My best regards

atajabbas

Re: A tangent problem

imajar — Mon, 19 Oct 2020 14:58:56 GMT

Hi, I took a look at your file, but you did not ask a question in your post.

The blue part looks pretty close to being tangent already. Why wont it work as is?

As for the double fold, I'm not sure what you mean. Can you sketch it?

Lastly, I assume you have noticed that the green part is interfering with the red part. Do you intend to cut the end of the green part, or shorten it?

Re: A tangent problem

Anonymous — Wed, 28 Oct 2020 22:04:20 GMT

Hi sir,

Many thanks for your kind reply. My delay in response is due to non receiving any notification about your message. I'm sorry.

The attachment is a sample of what I mean by double fold.

The blue part is close but not tangent and I did it by trial & error. It does not accept Tangent constrain and that is my problem.

The green tube will be shortened so that it will not touch the red part and I left the trimming to the last stage after solving the problems.

Regards,

atajabbas