Big problems editing a sketch

john_smith077

Hello

I have got myself into a bit of trouble editing a Sketch.

My Sketch consists of two quite complex areas (call it "Area_A" and "Area_B".) that are connected by a simple pair of lines.

The problem is that my pair of lines was originally created [in error!] using a Mirror, and now I need to lengthen this pair of lines. In this way I am hoping to move Area_A and Area_B further apart. [If not I will have to do hours of work!]



FWIW, the history was that first I created "Area_A" and then I created "Area_B".
i.e. I worked from right to 

The strange the is that if I delete the two lines that connect Area_A and Area_B, much of Area_B stays black. 
i.e. It is properly anchored and so it can't be moved.


But I have now idea how come the whole of Area_B doesn't go blue!

Any suggestions? (I really, really don't want to rebuild Area_B from scratch)

Cheers

J


PS I am still quite new! 

steve_shubin

@john_smith077

The best thing to do is to post the link to your document so people can play around with it and see how to fix it

Post the URL

NeilCooke

Woah! Rule #1 - keep sketches simple - I guess you're learning that now the hard way. I'm afraid you may have no choice but to start from scratch again. If you really need to create everything in sketches (rather than building the 3D model one step at a time) you should at least do each "flange" in a separate sketch. Free advice.

wayne_sauder

@john_smith077

 the transform command should break all constraints.

mahir

I second @NeilCooke. This looks like you're trying to manually draw out a flat pattern for a sheet metal box with multiple steps/jogs and mitre flanges. The beauty of 3D CAD is this is much easier to do by designing the box in 3D and letting the CAD generate the flat pattern for you.

john_smith077

steve_shubin said:

@john_smith077

The best thing to do is to post the link to your document so people can play around with it and see how to fix it

Post the URL

Sorry, but I don't know how to do that!

EDIT
OK try this:
https://cad.onshape.com/documents/de034e825102d66adecc250b/w/0b31a58dee9a7f5e1c3b375e/e/c2754ce7c63d3b14534858f8?renderMode=0&uiState=62aa57e259d2e2753a799acc

Thanks

J

john_smith077

NeilCooke said:

Woah! Rule #1 - keep sketches simple - I guess you're learning that now the hard way. I'm afraid you may have no choice but to start from scratch again. If you really need to create everything in sketches (rather than building the 3D model one step at a time) you should at least do each "flange" in a separate sketch. Free advice.

I am trying to create a book-cloth cover that will be glued to a box I am building. 
I am using a rubber hinge which is quite hard to model accurately. 

If I create this book-cloth part it in multiple separate Sketches, presumably OnShape will create multiple separate Parts, each of which I would then need to bond together.  :^(

J

john_smith077

mahir said:

I second @NeilCooke. This looks like you're trying to manually draw out a flat pattern for a sheet metal box with multiple steps/jogs and mitre flanges. The beauty of 3D CAD is this is much easier to do by designing the box in 3D and letting the CAD generate the flat pattern for you.

No, it's not sheet metal it's a layer of book-cloth going over a card box. I did wonder about trying to get OnShape to help generate the flat pattern...  [Maybe I still should??]

But the wrapping is quite complicated because:
A. In many places it needs to overlap over itself. [Can OnShape's sheet metal tools do that?]
B. It needs holes punched through it
C. It goes over 45 deg chamfers
D. If goes over a soft rubber hinge (that is already slightly hard to model!)
(E. Fwiw, I am hoping to print the Sketch on an A3 printer, and it would help with assembly to have the construction lines that I have drawn...)

And finally, because I am new and my small brain can only handle a limited amount of new information at once!

J

john_mcclary

Try not to take the "Sheetmetal" tool literally.
That tool is for any material that you want to fold/flatten.
-cardboard
-paper
-etc.

Sheet-metal is just the typical use for that modeling suite, so it inherited the name 'sheet-metal'.

steve_shubin

@john_smith077

As per @wayne_sauder   you can use TRANSFORM within the Sketch

john_smith077

steve_shubin said:

@john_smith077

As per @wayne_sauder   you can use TRANSFORM within the Sketch

Thanks, both. I think that may get me out of jail... 

I shall investigate the Sheet-metal thing next time/when I have time.

Cheers

J

tim_hess427

@john_smith077 - Just want to point out that you CAN make a single part from multiple sketches. This is done all the time. 

If you're extruding a part, for example, you can do Extrude1 using sketch 1, then Extrude 2 (selecting the "Add" tab in the dialog box) using Sketch 2. If the two extrudes are touching, they'll automatically be combined into a single part. 

john_smith077

john_smith077 said:

steve_shubin said:

@john_smith077

As per @wayne_sauder   you can use TRANSFORM within the Sketch

Thanks, both. I think that may get me out of jail... 

I shall investigate the Sheet-metal thing next time/when I have time.

Cheers

J

WAIT, I changed my mind. The Transform function is little better than 'living hell'. It murders almost all the relationships within the area of the Sketch that is being "Transformed". 

And given how hard it is within OnShape to see why any given line is blue, this is an utter nightmare.

Why can't Onshape just leave in place ALL of the relationships between lines within the area being "Tranformed"?

OnShape is brilliant in many ways, but editing Sketches is a major weakness.

This is extremely disappointing. 

NeilCooke

You need to try editing sketches in other parametric systems. They’re exactly the same. 

john_mcclary

Here is one method of how to model what you have in 'sheet-metal'
From this point, you can set some variables and make it parametric, but the concept is there

TEST001 (Document) - Copy | Part Studio 1 (onshape.com)


the only 'sketch' in the whole part was a simple square

S1mon

Ah. Yes, now I see what you're trying to do. I sometimes have sketches that are more complex than some people, but the only way I would ever have a sketch this complex in Onshape (or Solidworks or Creo) would be if I imported a DXF from another package as a reference. I would definitely do this very differently. I would model this as Sheetmetal, and try to do this by modeling the 3D shape and convert to sheetmetal and add the smaller details (chamfers, flanges, reliefs, etc). Onshape can figure out so much of this for you.