DXF Import Units Problem and Scale Limitation


#1

I am using a PCB layout program for circuit board design and export the 3D information for import into a mechanical CAD application as my standard design flow. I am considering a permanent move to Sketchup and have been trying to make the two CAD apps work together, to no avail.

There are 3 main issues that don’t make it easy to go to Sketchup.
1 - The PCB CAD software I am using is not very flexible with what is produced in the DXF output; so I have to use what it gives me (as everybody does). Its numeric base is in nanometers or something ridiculously small.
2 - No matter what Import Units I select with Sketchup it comes in HUGE. For instance, 1.750" = 145833’ 4". I have had it up to 884,000,000’.
3 - With the smallest import size (1.750" = 145833’ 4"), when I Scale the object down, I can only go to 1’ 5", and no smaller. This seems like a numeric limitation for the Scale feature in Sketchup.

If Sketchup could import micrometers or nanometers I could probably Scale it down to the correct size. At current, I do not have a good design flow path to get my 3D PCB’s into Sketchup to design around or validate a higher level assembly. I would prefer not to write/run a script to convert the DXF units, or run it through another CAD program to have a better starting scale units.

Any help to resolve would be appreciated. Thanks -Jeff


#2

For the scaling, have you tried using the Tape Measure tool instead of the Scale tool?
No matter what scale your geometry comes in or what units your model is set to, as long as you know the measurement of one thing in your import, you can use the Tape Measure tool to rescale the geometry up/down to its proper size.

Hope this helps

CD


#3

Hello Chris.

The Tape Measure Tool literally has no effect to scale the imported object.

-Jeff


#4

Can you upload the dxf so we can have a look?


#5

Here is the zipped-up file. - JeffBNVD_Controller_Tstbrd_v1.0-(BNVD_Controller_RevD_v1_0)3D_mm.zip (402.9 KB)


#6

I definitley see the issue of the imported scale. Strange!

In this animation, you will see how I changed the overall scale of the import.

Let’s say I knew the height of the board was supposed to be 10"…

  • Enter into the component (Edit Component mode)
  • Using the Tape Measure tool: Click top of board --> Click bottom of board --> now type the value it should be (10") --> Enter!

RESULTS: Now the entire import is scaled down proportionally to accommodate the 10" height :slight_smile:

5ae0e77f0f3d7265266031


#7

I discovered I had not been in Component Edit mode when applying the Tape Measure to scale it. I was now able to scale the object to actual size of 1.250H x 1.75W. Thanks for the quick response and the help to resolve. -Jeff


#8

Side note:
The reason your initial attempt didnt work is that SU tries not to scale items that are inserted from an outside source like dwg imports and inserting components from the component browser.
Components and groups that are created within the project WILL scale without having to enter into the component.

This is important to understand because if you are scaling with the tapemeasure tool without entering into the component context, everything in your model that was not inserted from an outside source will also scale.


#9

This topic was automatically closed 183 days after the last reply. New replies are no longer allowed.