topic Re: Changing parameters ruining extrusion cuts later in pipeline! in Fusion Design, Validate & Document Forum

Changing parameters ruining extrusion cuts later in pipeline!

Anonymous — Sat, 15 Jul 2017 19:21:54 GMT

I have had a consistent issue with a model I am working on. I produced a sketch and revolved it around a line, later down the line I added extrusion cuts specified using lines/construction lines. When I go back to the first sketch and attempt to change the diameter of the model it ruins all of the extrusion cuts I made because the lines are no longer in the correct place. How do I correct this? I included photos of the model and the model itself. Please help!

Re: Changing parameters ruining extrusion cuts later in pipeline!

SaeedHamza — Sat, 15 Jul 2017 19:34:07 GMT

Hi,

You have a major problem here my friend, because you've changed something so critical, and everything is built on, so going back in the timeline and fixing it and then going back to the present will cause you errors ( red things in the timeline ) and unexpected changes on the model.

What I mean is in your case rebuilding the model is the fastest solution here, which I highly recommend you to do

Regards

Saeed

Re: Changing parameters ruining extrusion cuts later in pipeline!

Anonymous — Sat, 15 Jul 2017 19:38:40 GMT

Ok, I have rebuilt it before and apparently repeated my mistake, how do I
avoid this issue when I build it next time?

Re: Changing parameters ruining extrusion cuts later in pipeline!

Anonymous — Sat, 15 Jul 2017 19:38:40 GMT

Ok, I have rebuilt it before and apparently repeated my mistake, how do I
avoid this issue when I build it next time?

Re: Changing parameters ruining extrusion cuts later in pipeline!

SaeedHamza — Sat, 15 Jul 2017 20:02:13 GMT

Well according to your model everything can be modified, except again for the main body because everything is based on it

First thing I recommend you to do is to avoid major changings like changing the section of the revolve of your first sketch

One more thing, if you want to add or cut some geometry of you main body, create the add/cut profile and revolve it to add it to the main body or cut it from it, that is the same as editing the first sketch, but a workaround so that you won't have to rebuild your model every time you want to change the main body

Regards

Saeed

Re: Changing parameters ruining extrusion cuts later in pipeline!

Anonymous — Sat, 15 Jul 2017 20:28:24 GMT

Thank you so much for your input, I have one last question that may seem redundant so I apologize in advance: are you saying I should not attempt to change the diameter of the body because it will disrupt all of the later changes regardless... or are you saying I should create an add/cut profile so that if I want to change the diameter of the body without disrupting the cuts I will be able to?

Thank you again for all of your help and patience!

Re: Changing parameters ruining extrusion cuts later in pipeline!

SaeedHamza — Sat, 15 Jul 2017 20:34:11 GMT

ask as much as you want my friend

I'm saying both, I mean if you want to change the parameter of the body, don't go back and edit the sketch, just create the add/cut without going back in the timeline, because yes, it will change everything based on it

Re: Changing parameters ruining extrusion cuts later in pipeline!

TrippyLighting — Sat, 15 Jul 2017 20:58:00 GMT

Conceptually what you are doing is not wrong, however, you don't apply/use the tools correctly so that things do not update properly.

The problem is really the first sketch which is really strangely under constrained. It almost looks like you deleted many sketch constraints. E.g most of the horizontal and vertical lines should have a horizontal/vertical constraint. Don't delete constraints unless you know precisely what you re doing.

Also even with all the sketch constraints properly applied I believe there are some dimensions missing to fully define this sketch.

Once that's one things should be fine.

Edit: I've tried to constrain and dimension that sketch but that is a bit hopeless. The reason why you need to re-build this assembly is simply beaus the first sketch needs to be re-done, without deleting constraints.

Re: Changing parameters ruining extrusion cuts later in pipeline!

Anonymous — Sat, 15 Jul 2017 20:51:52 GMT

So once I fully constrain the sketch I should be able to change the diameter without disrupting the cuts? I have a previous version that is fully constrained but still loses the cuts when I update the diameter... it is certainly possibly I used incorrect constraints or misapplied constraints to particular parts. I will try this though! Are there any constraints in particular that are critical to what I am trying to execute?

Re: Changing parameters ruining extrusion cuts later in pipeline!

TrippyLighting — Sat, 15 Jul 2017 21:01:13 GMT

@SaeedHamza wrote:

I'm saying both, I mean if you want to change the parameter of the body, don't go back and edit the sketch, just create the add/cut without going back in the timeline, because yes, it will change everything based on it

That is incorrect!

I do this allthe time and the ability to edit a sketch e.g. change a dimension to update features later in the timeline is one of the basics of parametric design.

If the sketch is done right this will work!

Re: Changing parameters ruining extrusion cuts later in pipeline!

SaeedHamza — Sat, 15 Jul 2017 21:46:32 GMT

I didn't mean that going back and editing a sketch is wrong, of course this is one of the great and useful features in Fusion

All I'm saying is everything in his file is based on that main body, and editing the diameter of the body will affect everything based on it, for example, if you have extrusions ( holes ) made of a sketch, changing the diameter will cause a problem, because the holes sketch position is fixed, and changing the diameter of the main body won't make them update to it.

This is the case I'm talking about when I said editing can cause problems

Re: Changing parameters ruining extrusion cuts later in pipeline!

SaeedHamza — Sat, 15 Jul 2017 21:55:54 GMT

For further explanation, this is what happens when I try to change the axis of the 2 revolve commands of the main body :

He wants to change the diameter after all, and not the revolve section, and that's by changing the axis location

Re: Changing parameters ruining extrusion cuts later in pipeline!

Anonymous — Sat, 15 Jul 2017 22:01:11 GMT

Ok now I am quite confused... FYI I have not deleted any constraints just have not yet fully constrained the sketch yet. For the sake of clarity, and I apologize for my redundancy and confusion...what approach should I take to make it possible to change the final diameter without losing my extrusion cuts?

Re: Changing parameters ruining extrusion cuts later in pipeline!

SaeedHamza — Sat, 15 Jul 2017 22:50:32 GMT

In my openion, changing the diameter can't be done without affecting the rest of the features, which I showed the result for that above in my previous post

If @TrippyLighting has something in mind that might help, it would be great

Cheers

Re: Changing parameters ruining extrusion cuts later in pipeline!

TrippyLighting — Sun, 16 Jul 2017 00:32:57 GMT

A sketch should be automatically constrained while sketching. Maybe you should create a screencast and show your sketching technique.

In this screencast I am describing what I see as the reason your stuff goes not update properly. I am working to re-create this part so I can show how it should work. We'll see how that goes 😉

Re: Changing parameters ruining extrusion cuts later in pipeline!

TrippyLighting — Sun, 16 Jul 2017 02:12:04 GMT

Here is the second screencast with a fixed design to show that changing the inner diameter of the ring will result in perfectly fine updating features later in the timeline.

I've attached the .f3d file for you to study.

Re: Changing parameters ruining extrusion cuts later in pipeline!

SaeedHamza — Sun, 16 Jul 2017 05:54:20 GMT

Nicely done Peter, I didn't know that proper constraining can be so useful

Re: Changing parameters ruining extrusion cuts later in pipeline!

Anonymous — Mon, 17 Jul 2017 05:19:05 GMT

AMAZING! Thank you for helping me with this, I have learned a tremendous amount about the importance of proper constraining as well. I am not sure why all of those constraints did not automatically appear, but I can certainly see the problem with them missing!