Contour milling a hole in stock Problem

[berntd]

I run 2018.

I have a part with a hole and I try to create a toolpath to mill that with a smaller endmill.

This is a depth cut. where I actually want to cut this part out of thin sheet stock mill everything as slots in the diameter of the endmill.

I create the geometry by only selecting select the inside face of the hole.

But when I generate the toolpath, it mills the inside of the contour (correct) and then goes round a second time OUTSIDE the contour.

This happens to any hole I tried with.

When I anaylze the chains for this geometry, it says there are 2 chains but I only ever created one.

How do I work around this?

I select the hole inside surface like this:

(Note the 2 green arrow going in opposite directions?

 

I then generate the toolpath and I can see that 2 "paths" were generated, one correctly inside the contour and the other outside:

 

I checking the geometry selection, it only show the correct face but strangely 2 sets of arrows in the model:

 

 

 

 

Centre piece_2.mcam

[#Rekd™]

Your file shows each toolpath with 1 solid chain selected, this looks correct.

Work on using Levels to separate your geometry. Move your solid body to a new level and name that level "Solid Model". Then move all your surfaces to a new level and name it "Surfaces". Then if you need any wire frame geometry put that on another level and name it "Wire frame Geometry". This way you can turn on and off the other levels making your geometry chain selection easier. 

[berntd]

58 minutes ago, #Rekd™ said:

Your file shows each toolpath with 1 solid chain selected, this looks correct.

Work on using Levels to separate your geometry. Move your solid body to a new level and name that level "Solid Model". Then move all your surfaces to a new level and name it "Surfaces". Then if you need any wire frame geometry put that on another level and name it "Wire frame Geometry". This way you can turn on and off the other levels making your geometry chain selection easier. 

Ok, thanks.

But now how fo I get the problem fixed with the incorrect toolpath(s) that mill on both sides of the selected hole edge?

[AHarrison1]

7 minutes ago, berntd said:

Ok, thanks.

But now how fo I get the problem fixed with the incorrect toolpath(s) that mill on both sides of the selected hole edge?

Pick the edge not the hole itself

[#Rekd™]

You might find it easier to start with wire frame chaining. Create a Curve on the top edge of the hole you want to cut. Do this on a new level. Then turn off your solid.

Solid chaining works well but  you need to make sure the selection is correct as @AHarrison1 stated above. 

[berntd]

9 hours ago, AHarrison1 said:

Pick the edge not the hole itself

I have tried that already but then it I can't get a depth toolpath into the material. It just creates a path in a correct circle but with 0 depth. I am not sure how to manually tell it to go down into the material based on an edge alone.

???

Best regards

Bernt

 

[AHarrison1]

10 hours ago, berntd said:

I have tried that already but then it I can't get a depth toolpath into the material. It just creates a path in a correct circle but with 0 depth. I am not sure how to manually tell it to go down into the material based on an edge alone.

???

Best regards

Bernt

 

This, along with many other toolpath related parameters, are controlled and within the toolpath parameters.

For example, the depth that you mentioned is controlled by the Linking Parameters page within the toolpath parameters.

[berntd]

14 minutes ago, AHarrison1 said:

This, along with many other toolpath related parameters, are controlled and within the toolpath parameters.

For example, the depth that you mentioned is controlled by the Linking Parameters page within the toolpath parameters.

 

Yes, I have set that up to be 0 at the top of stock and -2mm at the depth, see file. Yet it does not produce a toolpath past o based on the hole edge and if using the hole surface, it produces incorrectly 2 paths as mentioned.

???

 

 

 

[AHarrison1]

36 minutes ago, berntd said:

Yes, I have set that up to be 0 at the top of stock and -2mm at the depth, see file. Yet it does not produce a toolpath past o based on the hole edge and if using the hole surface, it produces incorrectly 2 paths as mentioned.

???

 

 

 

Compare your geometry selection for op2 and op3. In op2 it shows 2 chains linked to that hole surface, top and bottom.

Those chains in op2 are going opposite direction to each other. Once I got rid of the bottom profile the toolpath executed correctly.

Delete the bottom chain or re-pick the top edge.

Op3 only has 1 edge selected so that one comes out right.

I dont have 2018 installed anymore so I cant upload your file back with the fix.

[#Rekd™]

@berntd See this video I made of your file.

 

https://www.dropbox.com/scl/fi/whbfnzy2kd2u8ij7u81kp/2019Help.mp4?rlkey=wrmf647mopqjcysr1byt3vwwj&dl=0

[berntd]

12 hours ago, AHarrison1 said:

Compare your geometry selection for op2 and op3. In op2 it shows 2 chains linked to that hole surface, top and bottom.

Those chains in op2 are going opposite direction to each other. Once I got rid of the bottom profile the toolpath executed correctly.

Delete the bottom chain or re-pick the top edge.

Op3 only has 1 edge selected so that one comes out right.

I dont have 2018 installed anymore so I cant upload your file back with the fix.

Thank you. I did see that it has 2 chains when I did a chain analysis but as mentioned, I was not able to delete one or select the hole surface edge such that tghere woudl only be one chain. The other (correct) hole had the same issue but for whatever reason, it suddenly seemed to fix itself. I do not know how or why but it did.

How would you say one can unselect or remove that second unwanted chain?

Best regards

berntd

 

[berntd]

11 hours ago, #Rekd™ said:

@berntd See this video I made of your file.

 

https://www.dropbox.com/scl/fi/whbfnzy2kd2u8ij7u81kp/2019Help.mp4?rlkey=wrmf647mopqjcysr1byt3vwwj&dl=0

Hello,

 

Man, I do not know how to thank you enough!!

I really really appreciate that you took the time to do that for me. It is a great video.

I will re-study it over the next few days as there is a lot of valuable info there.

In my original, I did  try using that edge of the hole but I could never get the tool to step down on the Z axis. It just went is a circle and that was it.

But in your case, it does mill down so I will study that closely how you did that.

Thank you again for the great help!!!

I will report back when I have it working.

Best regards

Bernt

 

[#Rekd™]

13 hours ago, berntd said:

Thank you again for the great help!!!

Glad to help!

I am constantly learning from others here!

[AHarrison1]

13 hours ago, berntd said:

Hello,

 

Man, I do not know how to thank you enough!!

I really really appreciate that you took the time to do that for me. It is a great video.

I will re-study it over the next few days as there is a lot of valuable info there.

In my original, I did  try using that edge of the hole but I could never get the tool to step down on the Z axis. It just went is a circle and that was it.

But in your case, it does mill down so I will study that closely how you did that.

Thank you again for the great help!!!

I will report back when I have it working.

Best regards

Bernt

 

Bernt, I dont know your level of understanding of Mastercam and I am making the assumption that you are fairly new to Mastercam.

If my assumption is wrong then I stand corrected, however, I think you will gain a lot of info and guidance  from the tutorials found 

here https://www.emastercam.com/files/category/191-mastercam-2019/.

The links are for the 2019 version which is still very similar to 2018.

On the right you will find links to imperial (16) and metric (5) tutorials.

Good luck!!

[berntd]

8 hours ago, AHarrison1 said:

Bernt, I dont know your level of understanding of Mastercam and I am making the assumption that you are fairly new to Mastercam.

If my assumption is wrong then I stand corrected, however, I think you will gain a lot of info and guidance  from the tutorials found 

here https://www.emastercam.com/files/category/191-mastercam-2019/.

The links are for the 2019 version which is still very similar to 2018.

On the right you will find links to imperial (16) and metric (5) tutorials.

Good luck!!

Thank you that is very helpful as I know about 0 of Mastercam and have been figuring out and googling every single thing I tried to do. 
Best regards

Bernt

[berntd]

One more question about G code generation...

Thanks to the help here, I have managed to create suitable toolpaths for the whole part.

I now want to generate G code. Whilst that works, I am not able to get it to generate a file for all my toolpaths combined

It will either just do one my paths (if I highlight it) or some weird number of paths but not all of them.

How do I tell it to do them all? 
I am expecting a single .nc file with all the paths in it.

(The tutorials I have now seen just do a single toolpath)

 

Centre piece_2.mcam

[AHarrison1]

Right click Toopath Group-1

Edit selected operations (4th option down)

Change NC file name...

This will group your paths into one file

 

[berntd]

11 hours ago, AHarrison1 said:

Right click Toopath Group-1

Edit selected operations (4th option down)

Change NC file name...

This will group your paths into one file

 

 

It worked!!

That is not (in my opinion) intuitive and I would never have discovered that had you not told me. Thank you again.

Let me see if I can make that part next...

Best regards

Bernt

 

[berntd]

Hello again,

 

I am making progress but have hit another small hickup that I can't seem to solve on my own.

For the same part as previous, I have split the geometry so that the outer contour doe snot include the tiny slot as I found that problematic during milling,

 

Problem is however that instead of ramping clockwise around the outside of the part, the operation reverses every time it hits my added geometry.

 

What did I do wrong?

File is attached and it is the last toolpath named Outer Edge that has the problem.

Thank you very much again for any help.

Best regards

Bernt

 

Centre piece_2_experimental1.mcam

[#Rekd™]

4 hours ago, berntd said:

What did I do wrong?

See the video I created for you.

https://www.dropbox.com/scl/fi/w7c30jp8ocuxn311oth33/Chaining.mp4?rlkey=x1gon1hvmoebqqplv2kwjpxee&dl=0

[berntd]

@#Rekd™

Thank you very much again! I learn a lot from your videos. The toolpath seems fine now.

I already made one part on the previous version of my file (after your previous help) but then as the part broke out of the sheet, the little slot was not yet milled all the way through and on top of that, my only 3/64" endmill broke.

That is why I decided to change the toolpath and as soon as I can get another endmill, I will attempt version 2 of the part as per this later file.

 

Best regards

Bernt

[#Rekd™]

You can use “Tabs”, this will allow you to leave some thin support areas so the part doesn’t separate from the stock.

[berntd]

1 hour ago, #Rekd™ said:

You can use “Tabs”, this will allow you to leave some thin support areas so the part doesn’t separate from the stock.

Ohh really? that will great!

I saw something about tabs but had no idea that is what they are for.

I will investigate and if that fails, then that may become my next question

 

Best regards

Bernt