Does anyone have a TinyG 4th or 5th Axis post for Fusion360?

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AnonymousPerson
Posts: 758
Joined: Sun Apr 26, 2015 1:16 pm
Location: 3753 Cruithne

Does anyone have a TinyG 4th or 5th Axis post for Fusion360?

Post by AnonymousPerson » Fri Apr 06, 2018 5:09 pm

Hi all,

Took some time over the past week and a bit to create an initial prototype 4th axis for my
S3. It's super basic - just to get the hang of the concepts - and I've hooked it up to an
Arduino Due with g2core (current master branch) running on it, + some steppers wired
up on a breadboard.

I'm able to control all of the motors, limit switches, (etc) via manual G-Code, so at least
the initial 1st iteration of physical and electrical bits works.

Next up is getting something to generate tool paths. Fusion 360 seems like a reasonable
candidate (free, and widely available).

There is an existing "Tinyg" post processor that comes with Fusion360, but it seems to
only be for XYZ linear axis, instead of having rotational axis support too.

Has anyone been down this path already and gotten Fusion 360 to generate 4th or 5th axis
tool paths for g2core/TinyG2? Either indexing or continous is ok, just looking for something
that works "at all" as a starting point.

If not, I guess it'll be a case of looking at the other post's and seeing if they can be adapted,
but I'm just kind of hoping... :)
Shapeoko 3 #516

AnonymousPerson
Posts: 758
Joined: Sun Apr 26, 2015 1:16 pm
Location: 3753 Cruithne

Re: Does anyone have a TinyG 4th or 5th Axis post for Fusion

Post by AnonymousPerson » Sat Apr 07, 2018 3:37 pm

It turns out there's a fair amount of info around on how to customise and outright develop Fusion 360 posts, so giving that a go now.
And they have some initial basic post development training videos on YouTube too: My g2core-with-a-fourth-axis - post is in development here (filename of "g2core.cps") if that's useful: https://github.com/justinclift/Mill-Pos ... -g2core-v1

Something a bit weird with the post processor development workflow in Fusion 360, is that there doesn't seem to be a way to save the intermediate toolpath representation code which Fusion 360 sends to the post processor. And Fusion 360 auto-deletes log files, progress info, (etc). eg makes things painful for post development

To workaround that problem, I've whipped up a small utility that intercepts the call from Fusion 360 to the CAM360 post processor, and writes out the intermediate file, calling arguments, (etc), and saves them. It also generates a (windows) batch file for manually running the intermediate code through the post processor again, but with verbosity and debugging turned on to make things a lot easier.

Code is here, as it's probably useful for other people too:

https://github.com/justinclift/fusion36 ... nterceptor
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AnonymousPerson
Posts: 758
Joined: Sun Apr 26, 2015 1:16 pm
Location: 3753 Cruithne

Re: Does anyone have a TinyG 4th or 5th Axis post for Fusion

Post by AnonymousPerson » Sat Apr 07, 2018 7:42 pm

It turned out to be pretty easy to add new axis to the post (both 4th and 5th). Fusion 360 now runs through the post happily outputting A and B axis coordinates for the example part I'd modelled.

Only problem is, the example part should only need 4 axis. And when I reduce the machine capabilities to only 4 axis... Fusion 360 barfs. :?

Hopefully it's something simple, such as my not fully grasping Fusion 360's machine vs WCS pieces yet, from a CAM perspective at least.

Will continue on with it tomorrow, and see how it goes. :)
Shapeoko 3 #516

AnonymousPerson
Posts: 758
Joined: Sun Apr 26, 2015 1:16 pm
Location: 3753 Cruithne

Re: Does anyone have a TinyG 4th or 5th Axis post for Fusion

Post by AnonymousPerson » Sat Apr 07, 2018 8:54 pm

This is a Fusion 360 CAM post processor that just saves the intermediate file to wherever you select:

https://github.com/justinclift/Mill-Pos ... ediate.cps

Simpler than the interception approach above. The interception one though, does display the arguments
which Fusion 360 calls post with.
Shapeoko 3 #516

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