Undesired behaviour in 2D contour toolpath

[wordwrap]

Because I choose a complex design for my project, I made it difficult for myself in the production stage.
The project consists of 9 different "legs" each 50 layers.
Please see attached image.
I can produce most of the layers very easy and fast, but ...... there are lots of layers with a complex form.
In those situations I need to produce double sided, because there is a positive and a negative slope on at least two sides of the layer.
Double sided production is not the problem ......
The centre of the big hole is point zero.
The model has 4 extra holes that go through the spoilboard.
After rotating I put 4 pens in the holes + spoilboard and with this I reach the exact zero point (again the middle of the big hole).
To cut out the layer, I defined a 2D Contour toolpath and thereafter I do the slope with a 3D Contour.
After turning the layer I produce the slope in the other direction.
The problem is that the 2D Countour of the first layer takes away all the material for the second slope. So the second layer run makes no sense, because there is no material left.
I get the idea that this could be a program mistake.
Is there somebody who can help me please?

[lee_sanders]

Hi @wordwrap 

Seems like a very interesting project, would it be possible for you to share your project\session? it helps to understand your issue.

Thanks

Lee

[wordwrap]

It's available from now ....... https://a360.co/3rzh6pW

[mattdlr89 · Accepted solution]

2D Contour is not model aware and will just follow the contour that you select. If I understand correctly it looks like you should have selected the top edge of the part as shown below rather than the bottom edge that is selected in the file...

Select this edge instead - you will also have to change the bottom height in the heights tab to make it work. 

[wordwrap]

Thank you so much for your help. It works.

[wordwrap]

After changes the top edge of the 2d contour, the next step (3d contour) gives a message.

Can you please have a look a this?

[mattdlr89]

You'd have to share your model again. Although looking back at it I realise my first solution might not be so good as selecting the top contour you will have the same problem on another side. 

You would be better off selecting edges individually. By holding Alt while you select you can select individual contours rather than a chain/face.

Once you have updated the 2D Contour4, Contour1 will have a red warning because the above operation has changed. This can be cleared by re-generating the toolpath. Click the toolpath then press Ctrl + G.

[wordwrap]

I'm making progress, but there is one thing left .....
I switched on "Rest machining", but the is still a little machining without any need.
Can you please instruct me how I can get rid of this?
I made the modell available ......  https://a360.co/3rBfxYO

[mattdlr89]

I had a quick look at this. I don't think rest machining is really the right strategy here. As you model is quite simple I'd stick to using 2D contours. You can machining a taper with a 2D contour. 

I've attached the file with a few changes. The main thing was splitting out the 2D contour into two operations as it was doing something a bit odd and adding a tangential extension so it machines beyond the edge of your part.

I've then replaced the 3D contour with a 2D contour with a 9.5 degree taper. I think that is what your part is. I haven't checked any finer settings or feeds and speeds but I think this should give you a good idea of one way to machine it. 

[wordwrap]

Great solution!!!
It's a little more work, but the result is great.

Thank you so much.

[wordwrap]

May I ask you another question?
I have troubles with generating a toolpath ..... really have no idea how to define the fillet
Thia is the model ... https://a360.co/3cY6P0C
Could you please have a look on it?
Thank you !!

[lee_sanders]

Hi @wordwrap 

You could try using the scallop strategy,

I hope this helps

Regards

Lee

[mattdlr89]

@wordwrap 

Lots of ways to do it. Also depends on what kind of tool you want to use. You can do it with a 2D contour if you have a corner radius tool. Otherwise you can do it like @lee_sanders mentions above. 

There are a couple of other possible ways too but they all achieve the same at the end. It comes down to what tool you want to use and what type of finish you need really.