Alternatives for creating this toolpath.

[JB7280]

I have this PITA slot that I need to machine.  I created the toolpath the best way I know how, however I'm pretty sure there's a simpler way to do it.  I created the geometry in the screenshot, and just drove a contour based on that geometry.  But it's a pain if I decide to change depth cuts, or anything like that.  Is there a better way?  Maybe something like waterline?  And if so, how would I control that toolpath?

Hopefully the pictures show up alright.  I had to resize them because of the size restriction.

 

Larger version of the pictures - https://imgur.com/FOUQcbl

[JParis]

You could create geometry at every DOC, trim each to be just as long as it needs...chain them all, then use a depth of incremental 0

It'll cut each depth where the geometry lies in Z depth

[JB7280]

Just now, JParis said:

You could create geometry at every DOC, trim each to be just as long as it needs...chain them all, then use a depth of incremental 0

It'll cut each depth where the geometry lies in Z depth

Thats actually exactly what I did here.  Only issue, is if I want to change DOC or anything, it's a bit of a nightmare.  I was just wondering if there was a more efficient way to git a similar (or better) toolpath.

[JParis]

You could try using "Trim" Toolpath...it's usually my last resort...

2021 TRIM TOOLPATH.mcam

[crazy^millman]

1 hour ago, JB7280 said:

I have this PITA slot that I need to machine.  I created the toolpath the best way I know how, however I'm pretty sure there's a simpler way to do it.  I created the geometry in the screenshot, and just drove a contour based on that geometry.  But it's a pain if I decide to change depth cuts, or anything like that.  Is there a better way?  Maybe something like waterline?  And if so, how would I control that toolpath?

Hopefully the pictures show up alright.  I had to resize them because of the size restriction.

 

Larger version of the pictures - https://imgur.com/FOUQcbl

Surface finish contour with a boundary and steep shallow settings to control the start and end depth.

Waterline with a boundary and steep shallow to control the start and end depth.

Flowline with surfaces from that area might have to use UV direct to get them aligned in the correct direction.

Swarf with just those surfaces sectioned out in a 3 Axis output.

Parallel to curve using just those surfaces sectioned out in a 3 Axis.

[Colin Gilchrist]

Surface Finish Contour

SHS - Waterline

Use a 2D boundary above, and use surfaces to drive the path itself. Don't select any "floor surfaces", or the fillet radius surfaces, unless you've got a corner radius which is smaller than any fillets on the corners.

The Surface Finish Contour or Waterline path will "slice" the walls, and create contour passes at each of these slices. Use the "Gap Settings" with SFC to give yourself "entry/exit" lines.

The one pain about this; you won't get the option to use Cutter Compensation.

Unless...

You hack the Post. 

plin0$           #Linear movement, mill motion test
      if tool_op$ = 15,
        [
        if cstart$ = 1,
         [
         if cc_computer$ = 41, cc_pos$ = 1
         if cc_computer$ = 42, cc_pos$ = 2
         ]
        if cend$ = 1, cc_pos$  = 0
        ]
      pmotion_su

 

Note > This hack will only work with Surface Finish Contour (tool_op$ = 15).

Make sure you use the Entry/Exit Arc/Line options, and set your Cutter Comp to "wear".

Also, use "allow arc/line outside boundary"!

If you don't use "Line/Arc Entry/Exit" options, then the Contour Flags basically "come on at the start", and "turn off at the end", meaning you don't get CC on/off for each pass. (Probably won't work on most machines...)

[Aaron Eberhard]

Remember, with Waterline (and all HST toolpaths, and multiaxis toolpaths, and...), you can use Stock.

For example, let's say that you waterline the whole inside and get this:

If you had a stock model that had the roughed out part:

In the toolpaths, go like this:

The results will be this:

Obviously, this is a poorly done example, but I think that it might make your life easier..

Waterline Stock.zip

[JB7280]

Thanks to all of you.  These are my favorite kind of answers.  Enough to get started, but vague enough that I still have to think a little!

5 hours ago, crazy^millman said:

Surface finish contour with a boundary and steep shallow settings to control the start and end depth.

Waterline with a boundary and steep shallow to control the start and end depth.

Flowline with surfaces from that area might have to use UV direct to get them aligned in the correct direction.

Swarf with just those surfaces sectioned out in a 3 Axis output.

Parallel to curve using just those surfaces sectioned out in a 3 Axis.

Would you suggest creating surfaces using a mirror image of the "gusset wall"?  Or will a boundary limit that for me?  Not at the shop to play around with it at the moment.

[crazy^millman]

47 minutes ago, JB7280 said:

Thanks to all of you.  These are my favorite kind of answers.  Enough to get started, but vague enough that I still have to think a little!

Would you suggest creating surfaces using a mirror image of the "gusset wall"?  Or will a boundary limit that for me?  Not at the shop to play around with it at the moment.

Mirror will work, just need to change the normal in the surface. The back wall that goes all the way to the top would be the other issue and you would need to trim it to the top of the highest point of the rib. I was throwing together a file to share with some options, but just no time today to get to it. Wanted to plant the seed to get you thinking in that direction.

[JB7280]

11 hours ago, crazy^millman said:

Mirror will work, just need to change the normal in the surface. The back wall that goes all the way to the top would be the other issue and you would need to trim it to the top of the highest point of the rib. I was throwing together a file to share with some options, but just no time today to get to it. Wanted to plant the seed to get you thinking in that direction.

Thanks Ron.  I'll be working on this part for a good while, so if you do get time in the near future, that'd be awesome.  

 

Regarding the mirrored surface, I wasn't necessarily referring to the mirror tool itself, just saying, a surface the same shape as the rib, but against the side wall.

[crazy^millman]

1 minute ago, JB7280 said:

Thanks Ron.  I'll be working on this part for a good while, so if you do get time in the near future, that'd be awesome.  

 

Regarding the mirrored surface, I wasn't necessarily referring to the mirror tool itself, just saying, a surface the same shape as the rib, but against the side wall.

If you mirror a surface the normal of the surface might get mirrored, but I am not sure. When you put toolpaths to the surface and it is on the wrong side then you will know if the surface did or didn't get the normal set the correct way. I made up a sample and just xfrom translate (sorry what it use to be called) Dynamic Transformed the surface and the normal was still from the first wall so I have to change the normal.

[JB7280]

4 minutes ago, crazy^millman said:

If you mirror a surface the normal of the surface might get mirrored, but I am not sure. When you put toolpaths to the surface and it is on the wrong side then you will know if the surface did or didn't get the normal set the correct way. I made up a sample and just xfrom translate (sorry what it use to be called) Dynamic Transformed the surface and the normal was still from the first wall so I have to change the normal.

OI think I understand.  I've honestly not used surfaces for much more than filling a hole, so when you guys talk about changing the UV of a surface and things like that, I get a little lost, haha.  I'll get there though!

[crazy^millman]

6 minutes ago, JB7280 said:

OI think I understand.  I've honestly not used surfaces for much more than filling a hole, so when you guys talk about changing the UV of a surface and things like that, I get a little lost, haha.  I'll get there though!

Well I go back to 1984 when I made my first game in DOS days. I have made models going back to the Windows 3.1 days when all we had was surface so U and V is a completely different thing than Surface Normal. U and V and the grain direction so to speak of the surface. Where is normal is what it mean the normal UP our Out direction of the surface. Since we worked with surface for so long the out direction was which way the arrow point when you look at the surface on the change direction.

Link to Surface Normal Information

U and V information about Surfaces

[So not a Guru]

X, Y, Z = U, V, W

[JB7280]

8 minutes ago, So not a Guru said:

X, Y, Z = U, V, W

I do understand that part, but until reading a little about it on this forum, I had no idea that surface had a flow direction, or "grain".  

 

19 minutes ago, crazy^millman said:

Well I go back to 1984 when I made my first game in DOS days. I have made models going back to the Windows 3.1 days when all we had was surface so U and V is a completely different thing than Surface Normal. U and V and the grain direction so to speak of the surface. Where is normal is what it mean the normal UP our Out direction of the surface. Since we worked with surface for so long the out direction was which way the arrow point when you look at the surface on the change direction.

Link to Surface Normal Information

U and V information about Surfaces

Thanks for that info Ron!!

[JB7280]

I should have also mentioned, right now I'm just trying to rough the material out of this feature.  The current state of the material after some optiroughing looks like this.

 

https://imgur.com/efh89bz

[neurosis]

17 hours ago, Colin Gilchrist said:

Surface Finish Contour

SHS - Waterline

Use a 2D boundary above, and use surfaces to drive the path itself. Don't select any "floor surfaces", or the fillet radius surfaces, unless you've got a corner radius which is smaller than any fillets on the corners.

The Surface Finish Contour or Waterline path will "slice" the walls, and create contour passes at each of these slices. Use the "Gap Settings" with SFC to give yourself "entry/exit" lines.

The one pain about this; you won't get the option to use Cutter Compensation.

Unless...

You hack the Post. 

plin0$           #Linear movement, mill motion test
      if tool_op$ = 15,
        [
        if cstart$ = 1,
         [
         if cc_computer$ = 41, cc_pos$ = 1
         if cc_computer$ = 42, cc_pos$ = 2
         ]
        if cend$ = 1, cc_pos$  = 0
        ]
      pmotion_su

 

Note > This hack will only work with Surface Finish Contour (tool_op$ = 15).

Make sure you use the Entry/Exit Arc/Line options, and set your Cutter Comp to "wear".

Also, use "allow arc/line outside boundary"!

If you don't use "Line/Arc Entry/Exit" options, then the Contour Flags basically "come on at the start", and "turn off at the end", meaning you don't get CC on/off for each pass. (Probably won't work on most machines...)

This is pretty cool

I assume that you could add a flag (terminology?) in misc integers to turn this on or off? 

I would add this to my post but I'm afraid that it would help some times and give me headaches others. Mostly do to my own lack of organization. 

[crazy^millman]

5 minutes ago, neurosis said:

This is pretty cool

I assume that you could add a flag (terminology?) in misc integers to turn this on or off? 

I would add this to my post but I'm afraid that it would help some times and give me headaches others. Mostly do to my own lack of organization. 

I recommend this to someone trying to achieve this with Waterline on the Official Mothership Forum.

[neurosis]

8 minutes ago, crazy^millman said:

I recommend this to someone trying to achieve this with Waterline on the Official Mothership Forum.

LOL.  you beat me to the thought I see. 

If you could have this default to off in the misc values it might be a little more forgiving and allow someone to 'forget' to set the lead in/out properly every time.   

[crazy^millman]

2 minutes ago, neurosis said:

LOL.  you beat me to the thought I see. 

If you could have this default to off in the misc values it might be a little more forgiving and allow someone to 'forget' to set the lead in/out properly every time.   

Make Zero the default and then it will only happen when you put a value in there to use it. Would have to always go one way if you ever invoke this hack though. Where it would be nice of the developers of the software would add this ability. Then they would add the correct logic to error check and not allow Comp if in a Zig-Zag finishing process only in one way that is to the correct side. If left then G41 if right then G42. Might could error check the post to see if that drop down was switched tto Zig-Zag and not out put the Hack, but now we just threw this over to the professionals at that point.

[CADCAM3D5AXIS]

^ Ron and Others    ^   and That's why The Computer Science Engineers Get The Big Bucks ?

[Colin Gilchrist]

1 hour ago, crazy^millman said:

Make Zero the default and then it will only happen when you put a value in there to use it. Would have to always go one way if you ever invoke this hack though. Where it would be nice of the developers of the software would add this ability. Then they would add the correct logic to error check and not allow Comp if in a Zig-Zag finishing process only in one way that is to the correct side. If left then G41 if right then G42. Might could error check the post to see if that drop down was switched tto Zig-Zag and not out put the Hack, but now we just threw this over to the professionals at that point.

None of these checks are difficult to implement, provided you know how. (It just so happens that I know enough to figure it out.) The new opinfo function makes it easy to check the status of the settings for Toolpath Parameters, so adding some logic to make sure 'one-way' is the mode, that you're using entry/exit lines, etc., is certainly doable, inside the Post. I'll set this up as an example, using a Misc. Integer to control the Cutter Compensation output for Surface Finish Contour paths. 

It would be super helpful if there were just two checkboxes added to the interface.

• Output CRC for one-way cutting
• Perpendicular Entry for Line/Arc entry/exit moves. (Make the line Lead In perpendicular to the Arc.)

I will  have to check but there may be a way to see the 'next move' contour flag, and also be able to "peek ahead" for the entry arc values. If I can get the "next two moves ahead", then I should be able to create the Lead In Line as a mathematical vector. Doing this would allow me to rotate the vector 90 degrees, to recalculate the Lead In XY Position, and force the Post to use the newly calculated XY (perpendicular) position on the Start position or End position of the lead in/out lines. So I may be able to overcome this issue with a work-around. Plus, it sounds like a fun challenge. 

[neurosis]

Out of curiosity, has anyone tested this little post hack to see if it works?

[Colin Gilchrist]

1 hour ago, neurosis said:

Out of curiosity, has anyone tested this little post hack to see if it works?

Lol, you mean besides me?

[neurosis]

6 minutes ago, Colin Gilchrist said:

Lol, you mean besides me?

Yes.   I pasted it in to one of my posts based on MPMaster and it didn't output the cutter comp g-codes. 

I'm not sure if I missed something?