# Sketchup and CNC



## Mr T (6 Jul 2010)

Hi

We think it's time we started using CNC (not ours, we'll subcontract). How good is skecthup pro at talking to CNC? Can it produce files in a format readable by cnc machines?

Chris


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## SketchUp Guru (7 Jul 2010)

Hi Chris, you can export DWF or DWG files which could then be converted to G-code. I've not done it but I've read a little about it. You need some way to convert the DXF to the proper file type for the CNC machine.

Slightly different--Yesterday I was asked about making images from SketchUp that could be used as height maps by a carving machine called CarveWright. Evidently the image I made and show here worked fine for that.







I think a search of SKP to CNC or SKP to G-code will turn up some stuff for you. Also search for Phlatboyz. They have some interesting hardware as well as a plugin to allow you to make stuff with their machines from SketchUp.


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## SBJ (7 Jul 2010)

Sketchup is not an ideal platform for use with CNC. I find it brilliant for creating 3D visualisations of projects but I dont use it for creating CNC output.


I assume that you are thinking of using a 2D/2.5D flat bed CNC for cutting out parts from panel stock? 

You are better off looking at a CAD system - there are plenty out there, some of which are free. That said, speak to you CNC people and ask them what they want/recommend. I do some CNC work for my brother and his files always seem to be a bit buggy and take a lot of work to get them useable.


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## RussianRouter (7 Jul 2010)

Mr T":1tq44i5i said:


> Hi
> 
> How good is skecthup pro at talking to CNC? Can it produce files in a format readable by cnc machines?
> 
> Chris



You want to use Sketchup with a CNC machine? are you serious lol

Find a cam program that was designed for CNC.


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## wizer (7 Jul 2010)

RussianRouter":3m9uymiw said:


> Mr T":3m9uymiw said:
> 
> 
> > Hi
> ...



A great deal of people are doing it. What's so funny? It outputs to DXF, so it does work.

I do agree that for serious work then you need to go for a proper CAD/CAM programme. I've been learning TurboCad for this purpose and I'm finding the learning curve steeper than it was with SU, but I'm getting it.

Chris. What exactly do you want the CNC to do?


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## Mr T (7 Jul 2010)

Hi

RR wrote:


> You want to use Sketchup with a CNC machine? are you serious lol
> 
> Find a cam program that was designed for CNC.



I don't see the need to be quite so dismissive, I assume this is what passes for being direct for scousers.

I have no experience of working with cnc. It's taken me about four years to get the hang of sketchup and I don't want to spend a few thousand quid and another four years learning on cam software just yet. Sketchup pro may be a cost effective way of dipping my toes in the water of cnc.

Wizer, initially I am interested in cncing the wave shape in the wave kitchen described in the projects and work in progress section. After that I am told the possibilities are endless!

Many thanks to those who have made useful comments.

Chris


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## CNC Paul (7 Jul 2010)

Mr T":2xcvhsy9 said:


> Hi
> 
> We think it's time we started using CNC (not ours, we'll subcontract). How good is skecthup pro at talking to CNC? Can it produce files in a format readable by cnc machines?
> 
> Chris



Chris,

Any cad programme that outputs DWG or DXF will be fine for CNC but you will need a CAM programme to produce the machine code, I use Aspire by Vectric which I think is the easiest CAD/CAM programme to use. There are other 2D programmes in their range.

I to would not put down Sketchup, I have a friend that designs programmes for Shopbot CNC, he told me Sketchup were getting a CNC to play with and tryout stuff in their office. Using a CNC would be perfect for you wave kitchen.


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## SBJ (8 Jul 2010)

CNC Paul":1619h0ts said:


> Mr T":1619h0ts said:
> 
> 
> > Hi
> ...



I thought that sketchup curves were just a series of lines rather than "true" curves? How would you get over that?


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## CNC Paul (8 Jul 2010)

SBJ":1shq5w5h said:


> CNC Paul":1shq5w5h said:
> 
> 
> > Mr T":1shq5w5h said:
> ...



Stuart,

You are correct, but there is a Sketchup Ruby to draw Bezier Curves. I think most of the CAD/CAM programmes will also convert to Bezier Curves.


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## SketchUp Guru (8 Jul 2010)

All curves whether drawn with the native Circle and Arc tools or with plugins such as Bezier.rb and the BezierSpline extension approximate curves using straight line segments. In most cases you can control the number of line segments to adjust the smoothness of the curve. For most applications the default number of segments is adequate. Perhaps, though, you would want to increase those values for models being used for CNC work. For other applications, one should be judicious in deciding when to increase the number of segments used for arcs and other curves. Increasing the number of segments will increase file size and can result in some faces not being filled during Follow Me or Intersect operations.

In the reading I've done, there has been mention of smoothing options in the software that handles the conversion from DXF/DWG to G-code.


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## SketchUp Guru (11 Jul 2010)

FWIW, I doodle out this thing today.






And I created a quick height map.






A friend imported the image into their CNC Simulator and got this.






She's going to try actually carving it with her CNC machine later this week. Looks like it should work, though.


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## SBJ (11 Jul 2010)

have you got any write ups of this Dave?


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## SketchUp Guru (11 Jul 2010)

Stuart, are you referring to creating the height map?


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## SBJ (11 Jul 2010)

Yes Dave, although I wouldn't know how to create those shapes accurately in sketchup either


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## CNC Paul (11 Jul 2010)

Dave R":fq4eipgv said:


> FWIW, I doodle out this thing today.
> 
> 
> 
> ...



Dave,

Very nice sketch, how was it converted ? Artcam or Aspire


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## SketchUp Guru (11 Jul 2010)

Stuart, the height map is dead simple. Set up a 2D view that is appropriate and set the camera to Parallel Projection. Also use Zoom Extents to fill the drawing window. Turn on Fog (Window menu), untick Use Background Color and set the color to black. Then you have to play with the fog sliders until you get a tonal range that will work. Edit the style and untick Display Edges as well as Profiles if it is ticked. Export a JPG to make the image.

Thank you, Paul. The sketchy look was created in FotoSketcher from a JPG. In SketchUp I made the background color a green and I applied a sketchy line style. The face color was set by editing the front face color and shadows were turned on.


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## SBJ (12 Jul 2010)

thanks Dave


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