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How to get a 2D drawing out of Sketchup Dream and design
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Prolific poster 3,069 posts DKRickman Prolific poster 3,069 posts
DKRickman

This may be obvious to experienced Sketchup users, but I just figured it out, and thought it might be useful to someone.  I have some experience with both 2D and 3D CAD now, and I have found both to be quite useful.  3D is great for developing complex models and seeing how all of the parts will fit together.  2D is perfect for making flat drawings (such as plans to be printed out), and it easily does some things which Sketchup doesn't do well (like drawing curves).  Until this morning, I have not been able to easily convert a 3D drawing in Sketchup into a 2D DXF.  Every time I tried to export a DXF from Sketchup, all I got was a single line - not very useful.

In case you're wondering why you'd want or need to do that, I can think of a few reasons.  In my case, I am trying to develop a complex laser cut model, and Sketchup has been invaluable for making sure that all of the pieces fit like they should, and also for seeing how the whole thing should look.  I need to convert the 3D model into a set of 2D plans for the laser cutter, though, and I have not been looking forward to having to redraw everything manually.

With a little trial and error, I figured it out.  Here's how I did it:

  1. Open two copies of Sketchup.  One should have the model in it, the other should be empty.
  2. Select and copy the object you want to have a 2D drawing of, and paste it into the empty drawing.
  3. Rotate the object so that the desired face is aligned with the red and green axis, red being horizontal and green vertical.  The vertical (blue axis) location is unimportant, as is the location relative to the origin.
  4. Export the DXF with the desired units, and with DXF option < lines> .  Name it whatever you like, but be sure to include the ".dxf" at the end
  5. Open the resulting file in your 2D CAD program to check for errors or stray objects.

That's it.  You can then edit the DXF drawings as you would any other.  While you could save a step and export objects directly from the primary model, I do not like that option for two reasons:

  1. The orientation of the resulting drawing is not always what you expect.  Since orientation is critical to getting the right face exported, I chose to take the extra step to maintain control.
  2. I do not like the idea of modifying the original model.  Even if you could control the orientation issue, you would still have to rotate the model for each part.  Especially if the model was drawn to align with multiple photographs, changing the orientation would make it difficult to get realigned later.

Ken Rickman

Danville & Western HO modeler and web historian

http://southern-railway.railfan.net/dw/
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Bernd MRH Author 5,633 posts
Bernd

A better solution

Ken,

I was just surfing the net and came up with a "FREE" 2D cad program. It's called "DoubleCAD XT v5. After I loaded it I discovered that it's almost identical to the TurboCad version I bought last year.

Give it a try. Here's where you start. http://www.doublecad.com/DoubleCAD/DoubleCADXTv3/tabid/1100/Default.aspx

There is a form that needs to be filled out. They then send you the download instructions. On it you will find a serial number and activation code. These are used to activate the program and be able to load it on your computer. Give it a try. It even does 3D in with the 2D drafting program.

I was going to try and persuade you to get a 2D drafting program so you can learn drafting. Looks like you were thinking ahead of me here.

Bernd

New York, Vermont & Northern Rwy. - Route of the Black Diamonds - NCSWIC
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Bernd MRH Author 5,633 posts
Bernd

An addition

Having been in the machine tool industry I believe I know a little bit about drawings. Now that you have a drafting program you need to know how to make a drawing of a part and how dimension it. Here's a good place to start.

Google with this search term. (copy this and paste into browser) "blueprint reading for the machine trades" It'll come up with lots of links. Get the "Blueprint Reading for the Machine Trades  - Sixth Addition, unit 1 and unit 2. They look to be power point presentations. Very infomative.

Bernd

New York, Vermont & Northern Rwy. - Route of the Black Diamonds - NCSWIC
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Benny MRH Author 7,188 posts
Benny

...

You got it, Ken.

First, you have to put your desired face on a single plane, aka, lay out your parts.  On my projects, I take the finished 3D model and I "blow it apart," copying the faces and pasting them on a flat sheet with other parts that are all meant to be cut the same thickness [or double thickness, in which case two are cut]

If you have my lasercutter, The next step is to get the Flight of Ideas plugin and Inkscape.  Flight of Ideas kicks a file over to Inkscape, and then by using the Print function [and selecting my laser cutter as the printer] I can then cut the file from my laser cutter program.

I don't do any editing in Inkscape, I do all the editing in Sketchup to get my parts laid out on the face as required.  Inkscape simply makes it possible to transfer the file at scale to the laser cutter.  Inkscape also gives me sets of paths, so I can cut the edges separate from face detail.

I do this becasue as of yet I have not purchased any software to process my laser files, and I like it that way.

--------------------------------------------------------

Benny's Index or Somewhere Chasing Rabbits
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JodyG Regular poster 268 posts
JodyG

There is also a CAD program

There is also a CAD program that is free to download and use called DraftSight- its very close to Autocad, but FREE!
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Steven S Regular poster 265 posts
Steven S

If you want to make paper

If you want to make paper models (or just a paper mock-up), there's a plug-in for Sketchup called Flattery that will unfold your model for printing.  It's good for odd shapes like cupolas.

http://www.pumpkinpirate.info/flattery/


 

Steve S
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