CAM setups not working as expected

[Anonymous]

Hello, I am new to fusion 360 and fairly new to CNC machining. What I am trying is to make pockets on flat wood piece that have the depth as seen in the model. I have made many attempts to generate a toolpath that results to the desired pocket but with no success (two sample pockets in the file). Here is a link of my file, http://a360.co/2mBH8bG , any help would be greatly appreciated. I honestly do not know what I am doing wrong and I am really frustrated.

A note: the sketch is an imported dxf file created with adobe illustrator, I don't know if this affects the outcome but I thought mentioning.

[LibertyMachine]

The issue is in your Heights tab. For the Pocket operation, you have "Selected Contours" along with a -1MM offset. This will put it 1mm below the surface you selected.

The 2D Adaptive operation shares a similar issue. You have "Stock Top" along with a -1mm offset. Since you have an extra 1MM of stock on top of your model, it's only going to cut to the top of the part. You could select "Selection" and select the surface you want to cut to, or you can give it a value of -2mm from Stock top. (I prefer selections rather than calculated values, personally)

[Anonymous]

Hi, thank you for your reply. The problem is not with the depth that it is cutting at but with the shape it is cutting. if you look at the geometry that I am trying to cut it should make a pocket that has the shape of the storks mouth. To illustrate the problem I have fixed all the depth problems and made a screencast to illustrate the problem. The area that is cut is larger than what is bound by the chains I set in geometry. For the eye it behaves as expected.

Not sure why the screencast URL is not accepted but here it is: http://autode.sk/2mj5HIA 

[LibertyMachine]

Well, I really want to help you further, but I'm encountering a bug when I select a few things or simply regenerate the toolpath that you have created. I will circle back around when I have more info

[Anonymous]

Thanks a lot, looking forward for your reply!

[LibertyMachine]

Well, getting around that issue was minor. However, i still have some questions. i'm trying to weed out what is intended design versus inexperience with the software. For instance:

1) Are you really using a .1mm tool with 1mm length of cut? That is what you have your tool dimensions set to. I don't want to say that's impossible, but it will definitely be a challenge..

2) What's going on with this part, what's the deal with these cavities; intended or accidental?

Again, trying to resolve this issue, but I would like to know more about the intended design and resulting cuts. A lot of what we will be dealing with can be made a lot simpler if there are unintended features that can be cleaned up

[Anonymous]

How did you resolve that problem because I am getting it too some times 🙂

1) I am not sure what happened there with the tool (maybe  it wasn't properly saved) but for the screencast I actually used a 1mm tool. I will be using this tool only for the mouth for everything else I will use a vcarve engraving bit that has a cutting diameter of 0.1mm and a 10° angle but I don't mind the tapper that is going to result because of this. I have done this before and it is feasible. It would be a nice challenge to try with a 0.1mm tool indeed!

2) Here is an image of what I am trying to do: the outline will be gut and everything inside carved, so what you are pointing at is intended to make the mouth and the bag show. The outline isn't shown here because it will be cut on another machine.

Again thank you for your help!

[LibertyMachine]

For the error, tighten up the tolerance. Currently set to .1mm, try setting it to .01mm.

As for the rest, I will try to get to it this afternoon. Headed out for a customer delivery this morning and other stuff

I will state that .svg files and imported graphics almost always pose a challenge when trying to do anything more than tracing. We will most likely have to create new geometry to drive the toolpaths

[LibertyMachine · Accepted solution]

So here's basically what you need to do, or something along these lines:

I've projected the profile of most of the pocket onto a new sketch plane. I then went through and removed what artifacts came along with it. After that, I needed to make sure that I had a "closed" entity so I extended and trimmed as needed, finally finishing off with an arc to connect. If you wanted to avoid that area of the birds mouth, you could also draw islands around that area

[Anonymous]

First of all I want to thank you immensely four your time and effort! I will be checking this out in detail this afternoon (at least for my time zone 🙂 and I will report back! 

[Anonymous]

Sorry fir the delay but I was swamped. 

OK so I did this a bit modified and it worked. So my understanding is that there is no problem with my sketch but a complementary sketch used to define the area to be pocketed is needed. This to me is very weird. Since the model is properly extruded why would there be such a problem is beyond me. Further research is definitely needed but for now it will do!

Thank you once again.