Extrude and share sketch problems.

[Squawk]

Hello,

I've been breaking my brain over this..

Somehow I can't extrude several shapes in my sketch. I can't see the "share sketch" option in sketch 1.

After extruding 3 things, there is no extrude part available anymore, even though sketch 2 could be set to "share sketch".

I really need help with the following:

- why can't I choose "share sketch" for sketch 1?

- why does the "share sketch" feature of sketch 2 not allow me more than 2 extrudes?

- I made 2 sketches so that when I would use extrude, I can select an extrude per sketch. However, even though I select sketch 1, when trying to extrude sketch 1, it allows me to select sketch 2 features as well. Why?

- I cannot slelect the the feature without the round circle with legs, only the whole thing or the round circle with legs (see pictures). Why?

I hope somebody will have the time and energy to help me out..

Thanks in advance!

Squawk

[rdyson]

You can't share a sketch until it's consumed.
If you consume sketch2 before sketch1, sketch1 will be automatically shared.
I have no problem extruding multiple areas of sketch2.

[mdavis22569]

I think the problem is there are so many things going on in this sketch ...it's hard to tell what's part of what... Is it possible to extrude it in stages? That would probably help with sharing sketch ...

[Squawk]

Thank you for your reply.

But I have no idea what you mean with "consumed"..

Will try to look it up.

Either way, it will not let me select "share sketch" (see picture).

But I have to extrude different parts of the sketch to different values. They are not all the same.

[Squawk]

Thank you for your reply.

No, it will only keep letting me select what can be selected in the first try.

And after the third extrusion, it wouldn't let me select any other part to extrude anymore.

It looked like there was no sketch anymore to extrude..

The reason so many things are going on in this sketch is because I need to make a 3D form of the object that I then need to "cut" out of a foam filling of a case, to make a foam inlay.

My approach was to first make a simplyfied 3D shape, emerge it into a solid block (of foam) the size of the case, and then subtract that shape from the block (of foam) to make the space needed for the object.

Then cut it into 4 layers and project the cutout space into a 2D sketch for the water cutter company that can cut the foam for me.

I hope this makes sense..

[johnsonshiue · Accepted solution]

Hi! Sketch1 is already shared after it was consumed by Extrusion1. You just need to make it visible in order to create other features based off Sketch1.

Thanks!

[Squawk]

Yes! That's it!

Thank you for your help, it works now! 

[JDMather]

Once you have completed this part - attach it here and I will show you how it should have been done.

[Squawk]

Hello JD,

Yes, it is completed now. Including all the extruding etc..

How I should have done it? I'm self schooled (with the help of Google and YouTube) so I can guess my approach was not the most efficient one..

Very curious what you will show me.

I attached the part.

Thank you for any help!

[ampster401]

after looking at that screenshot, "KISS" comes to mind!

JD will cover it I am sure!

[Squawk]

lol.. yeah..

I was doubting about adding that screenshot.. 😉

Problem is that each sketch in that drawing need a different extrusion. So I had to draw them all.

[JDMather]

---

@Squawk wrote:

Very curious what you will show me.

---

I just realized that you are on r2012 (SP1?) was there only one SP for r2012?

I assume you used the Autodimension and Constraints tool.  Forget you ever saw that tool. 

There is a lot of symmetry in your part - the Origin Centerpoint should be positioned to make optimal use of this symmetry.

Use Feature Patterns rather than patterned sketch features (mirror is just another type of pattern - don't normally use in sketches).

Looked to me like you were missing some obvious Tangent constraints.

Given the information the feature tree does reveal - I am not even very confident the geometry really matches your true design intent. 

I suspect that you have about 50% more work than needed to make the part.

Can you get r2015?

What is the source of your dimensions?

[JDMather]

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@Squawk wrote:

...So I had to draw them all.

---

Nope!

[Squawk]

Thank you for your reply JD!

I didn't use the autodimension and contraint tool to add dimensions and contraint.

Only to check if I had forgotten any.

In a previous project I did, but it didn't make logical results and often I could make them clearer when doing/trying them myself.

The problem with this object is that it is not completely symetrical.

Only the left and the right size, but not front and back.

Plus the landing gear in the front and back is positioned differently.

I'm affraid that more that I spend much more than 50% of the work needed.

I first made a grid like measurement of the object because there is no drawing of it available (picture attached).

After that made that into a "coordinate based" drawing in Inventor (picture attached).

Then I printed it 1:1 on hard paper and cut out the shape. Where needed I corrected the drawing.

This way was sure it matches the object (if that is what you meant with "design intent").

After my "coordinate based" drawing was done I made the drawing on 1 side (the left side) from 1 origin point and then distances and angles as much as possible. This simplified the drawing. I checked some marking points from that drawing with the "coordinated based" drawing to make sure the dimensions were still the same.

After that I had the trouble of extruding things, but Johnsom Shiue solved this by pointing out the "visibility" option.

The result you saw in my previous post.

I bet you must be shaking your head when looking at the files attached, but I never received any instructions and have very very little experience..

It was the best I could do with what I had.

I only have the Inventor 2012 version.

Anyway, I am very happy with anything I can learn from you!

[JDMather]

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@Squawk wrote:

The problem with this object is that it is not completely symetrical. ....

After my "coordinate based" drawing was done (picture attached),

---

I can see.  I understand symmetry.  There is a lot of symmetry that you could have made use of.

When I am doing something like that - I place the picture image right into Inventor on sketch(es).

Scale the image such that image size more or less matches a couple of critical measured dimensions and then nothing else in that sketch(es).

I will try to post example later today.

[Squawk]

Thank you JD, I appreciate your help!

I didn't know one could import a picture and "overdraw" it (if that is what you mean).

But there is a problem with the source picture. There is some parallax.

for example the black round thing on the bottom (video transmitter antenna) sticks out much further than visible on the picture.

Anyway, I'm probably getting ahead of myself. Will wait for what you will show me later on.. 🙂

Thanks again!

[JDMather]

Yes, there will be parallax error using this method.

There are ways of reducing this, but in the end the image is used for reference.

You can't take it too literally when using as an aid for sketching.

[JDMather]

I recommend that you go through these, especially the Vacuum tutorial

http://home.pct.edu/~jmather/content/DSG322/inventor_surface_tutorials.htm

[Squawk]

That looks interesting.. 🙂

And it would have helped!

[Squawk]

Wow.. that looks extensive! Added to favorites.

By the looks of it, it's next level. I will try though!

(Can I send you an e-mail for those example files?)

Thanks for your help JD!