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Aug 30, 2019, 08:25 PM
springer's Avatar
Thread OP

new CAM tools for sketchup users SU to Gcode plugin

I have recently completed a CNC machine to cut foam using the needle cutter from this thread: My machine is shown on page 18 of the thread, and it works a treat for cutting Model Plane Foam and other styrofoam sheet. But this thread is not about it, but rather about a couple of tools I have found to create the files to cut. I use Sketchup V7 almost exclusively, as I find it has most all the features I need and those not native can be added with plugins. When I finished my machine, I needed a way to create the Gcode to drive it. I have the Phlatboys plugins loaded, but hadn't quite figured out how to use them, considering they are really for rotary cutters (i guess - mostly just too lazy to figure it all out!) I wondered if in all the plugins that have been created over the years there was one that automated the translation from .skp to .nc, and after some googling I stumbled onto a google site posting from 2010 of a wafer.rb that seemed to actually work going directly from a sketchup file to a Gcode .nc file. Once I tried it a while i noticed some "issues" with it, and tried to find the author (after 9 years) having only the Google site info. Eventually I found Duncan Law, via Linkedin, and found out that he was a poster here on RCG back in the day as well! We connected and he agreed to revisit the code to fix the issues and enhance it a bit. Turns out he's a programmer by day, so tinkering with ruby scripts is a relaxing diversion (I may be putting words in his mouth, but at least it seem that way).

The plug in is loaded into the plugins folder of V 7 in the normal way, and shows on the plugins pull down menu. To use it, I lay out my templates (all surfaces in z plane) arranged to fit the sheet I'm cutting, select all of them and use the "multiple_push_pull" plugin to extrude 5mm thickness to all of the parts. I then select all and run wafer. I get a dialog box with a bunch of selectable criteria like cutter diameter, etc. So far the defaults have all worked fine. I click OK and it asks for a file name and location to generate the Gcode. Enter that and click OK. It processes and both shows the cutter path next to the original parts and creates the Gcode in the named file. While it was pretty slow when I first tried it, taking a couple of minutes to do a 25part 2x4ft sheet, the last one I did using the V0.2.13 only took 18 seconds to run. The resulting Gcode doesn't have any feed speeds so I need to open and add them. Depending on where you set the Z zero, you may have to change that as well. It defaults to Z=0 as the location to cut, and I set my machine full down stroke to zero at bottom of stroke, so that works for me. I use the Universal Gcode sender program to send the code. It's free and seems to have everything I need: connects to the Arduino (eleksmaker 3 axis) board, browse for .nc file, jog functions to set and return to zero, and a decent path visualization. It also has a pause function that I have had to use from time to time to correct "oops".

The development of wafer is at the point where I can pretty much run it, open the .nc file add feeds and go run the cutter. I figured some of y'all might find that a useful tool set. Here's links to all the sofware:

Wafer: This is Dunk's github page. You can download the latest wafer file (0.2.13) from there. I suppose there is an easy way to download it but I just highlighted all of it, and copied it into a new notepad file named wafer.rb. Had to delete the .txt from the name notepad put on it, before using it.
Universal gcode sender: UGS is a java script Jar file.
The other plugin I found useful is multiple_push_pull.rb found here:
Ruby Script "Multiple Push/Pull" - SketchUp for Landscape Architects (1 min 15 sec)
Wafer needs part thickness to work, so the single surface templates need to be pulled up to the cutting height. this plugin does that for all templates at once, quite nicely.

I have tried wafer on V7, 2013 and 2015 it seems to work on all of them. I trust some of you will find it all useful!
Last edited by springer; Sep 23, 2019 at 10:30 PM.
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Sep 14, 2019, 08:06 AM
springer's Avatar
Thread OP
Lots of views, no discussion. Ah well, here's another use for wafer that I have discovered:

A bit of history first: my cnc machine started its existence as an Eleksmaker laser "engraver" ; half watt diode laser, letter size platten. I expanded it with some new extrusions from 8020 and added the Z axis that set me up for the needle cutter application. While the needler works a treat for cutting foam, and i have used it (with wafer generating geometry G-code) for several planes, i started itching for "even more capability". Tough being an inveterate tinkerer! I was able to stop by the home of dkjlinux, the developer of the current version of the needle cutter this summer. There, I saw his 2.5 watt laser and how much he has been doing with it. Back home I found it on sale at, so just had to get it. So now I have a needle or laser cnc.

I like to put N number identifications on my planes; makes them look more realistic, helps a bit with orientation and adds a little bling! I have had a friend with a Cricut type vinyl cutter make some, and have printed then hand cut others but wanted to do it myself. I find that the laser can cut the vinyl (or even colored packing tape without burning through it's backing paper/film. The trick is how to get the letters & numbers into gcode.

It turns out that sketchup has the key already built in. Here's my process: in a new file, i click on the 3d text icon. That brings up a dialog box where i enter the text, select font, height/size and extruded distance. I select 5mm as default extrusion. (One beauty of this is you can browse the web for hundreds of free truetype fonts). I then place the text, which is a sketchup group at the origin in the plan view. Once placed I explode the group for editing and running wafer. Sometimes they need a bit of clean up. Last night I did one where a couple letters were overlapping "solids". I removed the extra lines making each separate letter an individual item. Once I like the result, I run Wafer plugin from the plugins drop down menu. That generates a .NC gcode file that I save on desktop for easy access. I open the file and edit the speeds and feeds. Wafer automatically adds a Z action for cutting and retraction between cuts. I edit each of them replacing the G01 commands with M03 commands to turn laser on and off. (On my machine M03 S0 is off and M03 S60 is the right power setting for cutting). I set the laser to correct burn height/focus manually before cutting anything, so there is no need for any Z actions in the file. I have made 5 cuts of logos and N numbers so far and all came out perfect!
Sep 23, 2019, 09:58 AM
Summit Model Aeronautics
Steve85's Avatar
Hey springer,

Just came across this thread and think the SU tools you've found are really interesting. I tinkered with SU 7 a few years ago as a means of visualizing component assemblies in 3D without breaking the bank. Being able to directly from SU to G code saves a couple of steps. Thanks for posting!

Sep 23, 2019, 10:28 PM
springer's Avatar
Thread OP
Cool, hope it works for you. If it generates any questions, just ask. As I noted I tried wafer on both SU 2013 and 2015, and it worked ok.

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