topic Tool Path dipping below 3D contour resulting in mill crash in Fusion Manufacture Forum

Tool Path dipping below 3D contour resulting in mill crash

jgaertner — Sat, 11 Jun 2016 18:45:40 GMT

Hello Forum,

I am trying to make some soft jaws for my 6" vise. I made this parts drawing and created the G-code in Fusion and then I ran the part on my CNC Mill using a piece of MDF, to practice, while I am waiting for the real aluminum stock to arrive.

I throught I had left enough room above the vice for my MDF stock but I had the mill crash towards the very end of the G-Code and had to stop the Mill. What I do not understand is why the tool path is dipping below the fnished contour I am trying to mill out? If it is unavoidable, how do you know how much material you need above your vise since the path is not something I drew, so I do not know its dimension?

I have attached the file. Any suggestions or help would be appreciated.

Thanks,

Jgaertner

Re: Tool Path dipping below 3D contour resulting in mill crash

HughesTooling — Sat, 11 Jun 2016 20:36:36 GMT

I think for a job like this the only option is to make an extended surface and select it in the op under model. One thing you should always do is select the model in the setup, if you don't you risk machining into the model.

Here's a screencast to show how to setup the adaptive op.

Mark

Re: Tool Path dipping below 3D contour resulting in mill crash

jgaertner — Sun, 12 Jun 2016 00:08:41 GMT

Hello Mark.

Thanks for your help. Is it possible to see a larger screen version of your video? I have trouble following all the steps on the small screen. Why did you have to make my cut awy feature wider to be able to select it for an operation?

Thanks,

Jgaertner

Re: Tool Path dipping below 3D contour resulting in mill crash

jgaertner — Sun, 12 Jun 2016 01:21:20 GMT

Mark,

I think I found another way of doing the same operation. I did not have to change my part any, but used the "center of boundary" control and this time I paid more attention to the simulation and where the paths were the tool paths were going to go. See whether you agree that this will work too?

Re: Tool Path dipping below 3D contour resulting in mill crash

HughesTooling — Sun, 12 Jun 2016 09:45:42 GMT

The problem doing it that way is it will be done as a closed pocket so you end up with helical plunges that will take longer to machine. You probable should add some offset to machine just past the edge.

If you click the arrows at the bottom right of the screencast window it will go full screen.

Mark

Re: Tool Path dipping below 3D contour resulting in mill crash

HughesTooling — Sun, 12 Jun 2016 09:53:27 GMT

Here's the toolpath as an open pocket like my screencast.

Mark

Re: Tool Path dipping below 3D contour resulting in mill crash

jgaertner — Sun, 12 Jun 2016 12:19:40 GMT

Hello Mark,

Thanks for the tip on making the video screen larger! Now I can better understand the steps you did.

I am OK with the machining taking longer as everything I do is one off, not production work. I can't see redrawing, modifying parts in Fusion just get the tool paths to work? That makes no sence to me. I understand/appreciate that you have made a solution to my issue but these extra steps seem, to me at least, defeating the purpose of have a well working CAM software.

Granted, I still have a ton to learn in using Fusion so guess I will keep trying each new project as they come along.

Thanks,

Jgaertner