Engraving Single Lines on 4th Axis

[infoL6PB5]

I'm trying to engrave some lines on a round part. Wrapped tool paths just don't seem to want to generate. You can see a screenshot of my part.

I've tried:

• projecting the sketch as shown onto the surface
• using the 2d sketch at the center of the part
• using an offset plane

If I make some text, and select that, I get a toolpath.

Any ideas?

[LibertyMachine]

Could you share your part so we can play with it?
File > Export > Save to local folder. Return to thread and attach the .f3d file in your reply

[infoL6PB5]

Here you go

[daniel_lyall]

Are you cutting it on a mill or lathe?????????

[infoL6PB5]

On a lathe with a live tool, though the principle should be the same wrapping with a 4th axis or live tooling.

You can see text if added works as all tutorials seem to always use.

[LibertyMachine]

I "suspect" that there is a bug at play. I've submitted a request to have this file looked at and have an opinion rendered on it

[infoL6PB5]

Thank you!

Similar to my post on single face grooving, these kinds of operations I feel are needed for accuracy. I tried yesterday making a closed contour 0.05mm wide, but it seemed to be too small to be able to extrude to a curved surface. Going to try today and see how big it needs to be, but ultimately it would trace 2 lines, and end up with a less accurate mark.

[porsbym]

I took a look, and at least part of your troubles here arise from a somewhat hidden feature that allows you to select a planar sketch and use that for defining the wrapped toolpath.

This is handy if you want to do fully wrapped features, or if you want better control over the geometry (as well as proper arc support).

In this case, however, it doesn't detect that the sketch is a 3D sketch and already wrapped around the geometry.

Fortunately, this is user controllable albeit the controlling parameter is currently only exposed in compare and edit.

So one option is to use your 3D sketch with the projected lines, and then after creating the operation go into edit and compare and set "Unwrap Geometry" to Yes: 

Alternatively, create a 2D sketch and use that. Ideally, draw the sketch on a plane tangential to the wrap cylinder.

I hope this helps. In the meantime we will think about ways to make this less hidden.

/Mark 

[infoL6PB5]

Hi Mark,

Have you tried that with my part and a single line? I ask because I have tried all of those options, they work fine for closed contours that are large, or text that traces a double line. But not a plain single line.

Can you provide a file similar to the one that I provided?

Right now selecting either a flat or 3d sketch, I get this:

Error: No input contours have been specified.

[porsbym]

Attaching a version of your test file with two versions of your operation working.

For the first operation, I simply used Compare & Edit and set "Unwrap Geometry" to "Yes".

For the second operation, I cleared the geometry and picked Sketch3 from the browser.

I did notice now, that something odd is going on when picking single sketch segments. We will need to take a deeper look at this.

Let me know if this helps.

/Mark

[infoL6PB5]

Yes, still having problems. I have no idea how you got it to work 😞

I can't get it to work in my original part, but even on the test part, there's a lot of wasted motion in the tool path, it doesn't do vertical lines and then the horizontal, instead it draws a ton of L shaped lines. So if I un-select the horizontal, then an incorrect path is generated. Selecting the horizontal again, and it gives the same toolpath. See attached screenshot. This is on the regular 2D sketch.

The 3D sketch looks like I can unselect the horizontal and get a good toolpath on the vertical lines, but copying the same toolpath and selecting only the horizontal it gives me this:

Warning: Wrong geometry.

Warning: No passes to link.

Generation completed with 2 warning(s) in 133.6ms.

Warning: Empty toolpath.

I'm uploading the same file after editing the toolpaths. Maybe it will give more clues.

The only way I'm able to cut the part is by overlaying rectangles on the lines and cutting the line essentially twice, effectively doubling the cycle time.

[daniel_lyall]

Having the sketch in the center of the model is something you should not do, it can have all sorts of problems.

having the toolpath set like what is shown here works https://www.youtube.com/channel/UCrx-8M8nRa-rNlkwIowx6Kw just along the Z axis like what the wrap tool paths do if they are a standard 4th axis part.

What has been done to get it to work is used sketched lines in the center not projected lines, what has broken the normal wrap toolpath for it to work as a millturn toolpath.

[infoL6PB5]

Except that doesn't work for a single line. It works fine for text (since it will double stroke the text) or a very small rectangle. I have my code working for a 0.1mm wide rectangle, but as mentioned, it cuts double the amount of time than necessary for these type of engraving markings.

I've tried:

• Tangent sketch
• Sketch in middle of part
• 3D sketch projected onto the curved surface

Somehow Mark got the last one to work, but as mentioned needed was removing the horizontal line to get a good toolpath, then the horizontal line couldn't be added back. Anyway, hopefully it's figured out fundamentally in some way that lets selecting single lines easier.

On a flat surface, I've engraved single line stick text fonts from a sketch without issues FWIW.

[daniel_lyall]

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@infoL6PB5 wrote:

Except that doesn't work for a single line. What does not work

It works fine for text (since it will double stroke the text) or a very small rectangle. I have my code working for a 0.1mm wide rectangle, but as mentioned, it cuts double the amount of time than necessary for these type of engraving markings.

Why are you useing a .1mm rectangle with a 1/16 ball end mill

I've tried:

• Tangent sketch                                              have a look at the videos
• Sketch in middle of part                              this does work you have an example of it, you do the single line as its own op.
• 3D sketch projected onto the curved surface . yer this does not work

Somehow Mark got the last one to work, but as mentioned needed was removing the horizontal line to get a good toolpath, then the horizontal line couldn't be added back. Anyway, hopefully it's figured out fundamentally in some way that lets selecting single lines easier.

On a flat surface, I've engraved single line stick text fonts from a sketch without issues FWIW.

---

[infoL6PB5]

I recreated my original file again from scratch and it seems to have helped. In separate operations I think I can now get what I'm looking for or quite close. I used a tangent sketch, select the vertical lines only. Then creating a new operation rather than copy pasting the old one seems to have gotten me a valid toolpath for the horizontal line.

I do appreciate all the help, but I also think something funny is still going on. I can't figure out why sometimes toolpaths are valid and sometimes they aren't. It can be extremely confusing.

[daniel_lyall]

There are bugs playing a roll in it, half the reason it works is a bug a good bug.

Sometimes it just does not work and you have to start again, it is a pain as they are building the logic into the cam it will get better and say what is wrong.

[infoL6PB5]

I still have problems with this. I did get a good toolpath for one sketch and thought everything would be fine, but can't do the same type of toolpath 180 degrees on the other side of the part. Maybe eventually with fiddling and re-creating sketches and everything it will create correctly, but it's very frustrating.

[infoL6PB5]

Tried re-creating a totally new part all over again and can't get anything anymore. Attached is the file for anyone that can get it working, would love to know exactly what was done.

I'm using Fusion 360 version 2.0.4860 on Windows 10, maybe something with the OS or version has something to do with this?

[daniel_lyall]

I will do a vid when I get back from dropping my kids to school. there is something wrong with your model or the wrap function, I had to go old school on it.

[infoL6PB5]

Thanks! Must be in the sketch I'm thinking...I copied the working 2D contour and still didn't work, recreated, didn't work, so not sure 😕

In my original model it won't even generate a toolpath on the other side, just says no contours found.