Buildin' Projects: Solidworks to gcode for ShapeOko 2 using Autodesk Fusion 360 CAM

Tuesday, January 19, 2016

Solidworks to gcode for ShapeOko 2 using Autodesk Fusion 360 CAM

I've been searching for a while to find the best (and cheap) way to go from Solidworks 3D CAD files to gcode to run my ShapeOko2. After reading through the forums and trying a couple different options, the software the worked the best for me was Autodesk Fusion 360's built-in CAM package. Fusion 360 is a full featured 3D CAD package- and the best part is that it is free to students / hobbyists. I think that's a great strategy to widen their user base, and it's beyond me why Solidworks doesn't adopt a similar model.

The first parts I wanted to cut were some 1/4" thick 6061 aluminum sections for a home-built adapter to put a Trail-A-Bike on my Yakima roof rack.

I could have modeled the parts in Fusion 360, but since I'm more familiar with Solidwork's interface, I created the .prt files in Solidworks then imported them into Fusion 360. Another option for model creation is Onshape's excellent CAD package- which is very similar to Solidworks, and also free for Home users.

So, the software toolchain I used was:

Model in Solidworks, save .prt file
Import into Fusion 360
Use Fusion 360's CAM module to create the toolpaths
export Gcode
use gcode sender to send to Shapeoko2

Creating a toolpath from a .prt file is much more involved than simply 3D printing a part- with a lot more pitfalls. It took me quite a few tries to get the process to work property. I cut out a complete set of parts from 1/4" plywood before I even tried cutting aluminum- it's a lot cheaper to scrap than aluminum!

I found a good tutorial video on Fusion 360's CAM:
https://www.youtube.com/watch?v=XYoovemQoiM

Initially I had some issues with Fusion 360's generic GRBL post processor (plug in to generate gcode optimized for the Shapeoko's software). After some searching I found and improved one to use:

Discussion:
https://camforum.autodesk.com/index.php?topic=6144.0

Link to post-processor:
https://camforum.autodesk.com/index.php?action=dlattach;topic=6144.0;attach=7615

I did find a couple settings to tweak on the post-processor:
set "retractheight" to 5mm
set output units to "mm" - definitely do not forget this, otherwise you'll have big problems.

Cutting aluminum with the Shapoko was also a trial and error process- lots of experimentation with feeds 'n' speeds and lubricant. I liked CRC True Tap coolant / lubricant I found on Amazon. WD-40 and 3-in-1 oil also seemed to work OK.

The final Trail-A-Bike rack adapter worked great- and kept the Trail-A-Bike safely secured during a 1,500 mile road trip.

I did learn some lessons about the Shapeoko2 cutting aluminum. I really want to do any modifications possible to stiffen the structure- stock it's pretty flexible to try and cut aluminum at anything but a very thin layer / stepdown.

Also, the plywood trial copy didn't exactly work- it was slightly thinner than 1/4", and was a little misleading about actual fit on the Trail-A-Bike. The plywood version fit exactly right, and the aluminum didn't. And, since I finished the aluminum version the night before the big road trip I didn't have time to re-design and re-cut all the parts- so I broke out the dremel and manually ground the parts down to make them fit. They were a bit ugly but still worked.