topic Re: 3+2 axis milling, toolpath in the air in Fusion Manufacture Forum

3+2 axis milling, toolpath in the air

Anonymous — Sun, 19 Feb 2017 14:13:50 GMT

Hello everybody, New at Fusion (but having used Catia and Powermill) I try to reproduce a 3+2 milling project, the problem is that I could not find the proper set-up so Fusion does not mill in the air (or in this case in the table of the machine). I attached 2 screenshots, 1st of the toolpath, 2nd of the stock. I hope somebody can help me, I really want to use Fusion but I am stuck so far with this feature. Cordially Francois

Re: 3+2 axis milling, toolpath in the air

Steinwerks — Sun, 19 Feb 2017 15:20:56 GMT

Is it possible to share the file here? If so, go to File -> Export -> Save As .F3D and attach it to your next post.

If not, a dummy file would help a lot, or at least screenshots of your toolpath settings. We can certainly get your retracts down using settings such as Maximum Stay-Down Distance, Stay-Down Level, and Retraction Policy, all of which are in the Linking tab.

My starting go-to settings are these:

Re: 3+2 axis milling, toolpath in the air

Anonymous — Sun, 19 Feb 2017 15:41:34 GMT

Hello Steinwerks.

First tanks for your help, I attached the saved file.

I tried to play with the parameters you said but without success, still I am not sure I was clear enough, if you check the picture fusion3, you can see some toolpath (in the red triangle) which should not be (in myunderstanding) since there is no material there and they are not even links movement but really machining movement.

Cordially

Francois

Re: 3+2 axis milling, toolpath in the air

Steinwerks — Sun, 19 Feb 2017 16:02:39 GMT

Ah, yes I misunderstood.

What you are seeing is what is called the shadowing effect, in which the toolpath, looking at the stock from the Z (top) orientation believes there is stock until it reaches the maximum depth definition. I believe I've gotten this to work before but give me some time to work with it.

Re: 3+2 axis milling, toolpath in the air

Anonymous — Mon, 20 Feb 2017 09:07:29 GMT

Hi Neal,

Thx for the explainations and for your help !

Cordially

Francois

Re: 3+2 axis milling, toolpath in the air

Anonymous — Fri, 31 Mar 2017 11:28:14 GMT

Hi Neal,

Did you manage to solve the issue? (or is it a much bigger job)

Cordially

Francois

Re: 3+2 axis milling, toolpath in the air

jeremyah6364 — Fri, 31 Mar 2017 13:44:10 GMT

Here is what I came up with. I made a quick box that would represent your table in this situation. In the geometry tab, I turned on model and selected the "table". It now knows to avoid it. If you ever want to keep the toolparth from touching something, just make a quick model of it and select it under the model tab. Hope this helps!

Re: 3+2 axis milling, toolpath in the air

Steinwerks — Fri, 31 Mar 2017 22:56:41 GMT

I had to go find the part I was thinking of, and I had made a single surface instead of a box using the Patch environment, although implementation is essentially the same. If you want to cut all the way below the part, offset the solid or surface down by an acceptable amount.

Re: 3+2 axis milling, toolpath in the air

matty.fuller — Wed, 12 Apr 2017 07:34:03 GMT

I ran into a similar issue a few months ago, and as mentioned using Avoid/Touch Surfaces as mentioned will stop you going down past the part.

Depending on your machine retractions might not be an issue, but if so setting Minimum Retraction will solve a lot of your problems. It doesn't stop the path from retracting crazy high at the start/end of the toolpath and during some linking moves - see my post here for an example. For our machine I resolved this by patching the post processor to check the true Z height of rapid moves in relation to the machine's working envelope, and trim them down to a safe Z ceiling instead.

Obviously this is not a fix that can easily be shared, so if those retractions are an issue for you it probably requires changes to Fusion or getting someone to look at your machine + post in detail, unless someone else has figured out a technique.