Constraining assembly components.

[Squawk]

My intention is to make a foam inlay for a component.

The foam inlay however is not a square but has both tapered and little round sides.

I can make a "mate - flush" constraint and get the component to align the correct place in height.

But I can't find any way to constraint the closest proximity of the object to 1 mm from the sides.

Is there any way I can accurately set the position of the component from the sides, preferably constrained?

Please see attached file.

Thank you for any help in advance!

[Squawk]

I started to read through your Vacuum technique, but my skill and knowledge are not so far as to understand what I'm doing and sometimes even doing the same did not create the same results..

I should really finish this foam inlay so I decided to do with what I have now and go through that and some other tutorials later.

Your way of repositioning the way I used now worked quite well for me at this time! 🙂

[Squawk]

Thank you for your thorough explanation Curtis!

Very clear, even for me! 😉

I see how it's easily possible to create straight workplanes even though working with tapered surfaces.

And once having those, it is easy to make a parallel one that touches the most outer dimensions of a tapered side.

Awesomely explained!

Thank you also for the links of both re-setting the origin point (will add those to favorites because it's hard for me to remember by heart at this point) and the creating workplanes. Options are limitless it seems.

[Squawk]

Maybe I should start a new thread on this, but since we've been scratching surfaces of, I'll go ahead and post my question here..

In the light of the "new way" for me to compose a component, I've used centrepoint centered sketches, used symmetry constraining, construction lines and projected geometry. As much as possible (for my current level of understanding) as advised by JD, Curtis, some others and the various tutorials I've read recently.

And I was happy to find all lines turned blue despite of a (in my view) very clean creation, indicating all being fully constrained.. at least so I thought..

But when running "auto dimension and constraint" to check if I forgot anything, in all my sketches I get warnings.

Also Sketch Doctor seems upset and is incoherently mumbling warnings I totally don't understand.

I feel there must be simple thing I'm lacking that applies to all my sketches, since the sketches aren't very complex but yet all cause these issues.

Of course I can draw them my "old" way, but then I won't learn anything and I can already see JD shaking his head.. 😉

I hope I haven't driven you guys to despair yet and maybe want to help me on this.

I attached the .ipt file here:

[Squawk]

Ok, I deleted all the sketches and started again. But immediately, from the beginning, I end up with the same sketch doctor errors.

No matter what I try, I can't get it right.

Google and Autodesk Community searches on sketch doctor errors didn't resolve it either.

Here is my very simple file, that seems not to want to come into existence..

[JDMather]

Sketch1

It looks like you are doing the rectangle the "old-school" way.

Doesn't 21012 have the Centerpoint Rectangle tool?  (I can't remember back that far.)

But that is OK, you have a centered rectangle.

But what is the purpose of Top Work Plane?

Isn't it just a duplication of the XY Plane?

Any time a beginner is creating a workplane - this is almost always wrong step.

Your goal (as a beginner) should be to use only the BORN Technique.  Use only the Origin geometry to create the rest of your geometry.

I don't see any Sketch Doctor errors on your latest file?

[Squawk]

The idea is that I want to extrude that rectangle less than the big rectangle.

The reason why I created a new work plane, is because the next sketch (trapazoid) I wanted to symmetry sketch in the middle between the big rectangle top side and the small rectangle bottom side.

That sketch would not be symmetric around the origin point.

Only the big rectangle is symmetric around the origin point (yellow point).

See picture:

My 2012 version only has a "rectangle two point" and "rectangle three point" tool.

My sketch doctor does give me an error ("overlapping curves") on this very very simple sketch (also attached for clearity):

[JDMather]

---

@Squawk wrote:

But when running "auto dimension and constraint" to check if I forgot anything, in all my sketches I get warnings.

Also Sketch Doctor seems upset and is incoherently mumbling warnings I totally don't understand.

---

I recommend that you forget Auto Dimension and Constraint.  YOU should know when you have applied the required dimensions and constraints.  Simple geometry.  OK, I will allow as a test, but I still think you should forget that tool even exists.

You are not locating the origin in the logical symmetry location.

You have to consider the overall - not a single rectangle.

Edit your Top Plate sketch and right click select Show All Degrees of Freedom.

You have not tied down the ends of these construction lines.

Looks like you just "eyeballed" them to previous sketches.

You must Project Geometry from previous sketches.

[JDMather]

---

@Squawk wrote:

My 2012 version only has a "rectangle two point" and "rectangle three point" tool.

My sketch doctor does give me an error ("overlapping curves") on this very very simple sketch (also attached for clearity):

---

 I forget when they added the Center Point Rectangle tool.  Are you up-to-date on all Service Packs for 2012?

I think the Sketch Doctor can be ignored since you simply have an object line overtop of a construction line.

Frankly, I never use the Sketch Doctor except on other peoples sketches. If you know what you have done is correct, overrule the doctor.

Did I give you any information on the BORN Technique?  You should not be creating any workplanes unless you are doing a loft (or maybe sweep) at this stage of your work.

[Squawk]

On the original file I attached yesterday (my time) I used a lot of projected geometry to constrain my sketches.

But then the "red plus" from the Sketch Doctor showed up as soon as I tried to extrude the different surfaces.

That is how I ended trying to figure out all the errors in Sketch Doctor. It was preventing me from extruding anythying.

As for the whole of the rectanble, I see where my thought process went wrong. I redid the sketch the correct way.

I used the "horizontal" and "vertical" constraint tool to lock the rectangle down, as 2012 doesn't have the option you mentioned before (I'm not sure about my service packs, will look that up).

This is what I see when selecting "display degrees of freedom" in the old sketch:

As you can see, there are yellow and blue dotted lines.

That is where I tried to use "projected geometry" for my sketches. Obviously something didn't work..

But what does that information even tell me? What do you mean with "You have not tied down the ends of these construction lines."?

How does one "tie them down" and what would this above picture look like if I did?

Either way, my approach was all wrong with the new work plane idea.

So as I wrote above here, I redid the sketch and this time the whole rectangle around the center point.

Then made a new sketch called "top plate" and sketched the trapazoid that I can't seem to lock down with symmetry..

I did centre the long legs of the trapazoid around the X axis so that is symmetrical.

But I can't make it symmetric around the Y axis withouth the sketch doctor playing up and potentially preventing me from extruding it later.

Of course I can lock it down by just dimensioning it from some fixed point, but that is not the "preferred" way.

I attached my sketch. It became fairly simple now. Maybe you can have a look at this .ipt file:

[JDMather]

When you display degrees of freedom - the red arrows indicate endpoints that have not been constrained.

To "lock them down" you need to Project Geometry the lines from the previous sketch and then add Coincident constraints between the endpoints and the projected geometry (I always change projected geometry to contstruction - although this isn't a requirement, I almost never use projected geometry other than for construction reference.)

[Squawk]

I also made them construction lines and points, since they don't have any other function than constraining things. It seemed more logical.

But I'm not sure I understand what you mean with "add Coincident constraints between the endpoints and the projected geometry".

What "endpoints"?

[JDMather · Accepted solution]

These endpoints. 

At the red arrows indicating remaining DOF.

Done correctly - Inventor does this work for you.

[Squawk]

Thanks JD, for your answer and patience!

I made the construction line smaller, made the constraint point to the origin but after dimensioning the construction line, the problem was solved..

Strange how it suddenly worked. Must have done something different the first time.

[Squawk]

This problem is solved.

Thanks you all for your help!