Merge Hole segments in turning???

[Lonnie.Cady]

when using merge hole segments in turning on center it seems to be extending it too far.  Not sure what geometry it would be grabbing for the merge.

 

[Steinwerks]

@Lonnie.Cady

You have the "Drill Tip Through Bottom" activated with Stock Bottom and a break-through depth of .05"

Edit: do you mean the entry extension it seems to like?

[Lonnie.Cady]

@Steinwerks yep, but the hole is being extend in front of the part by about .6"

Did you open the file and just check and uncheck auto merge hole segments? You can see the toolpath extend to the front by way more than the chamfer on the bore.

[Laurens-3DTechDraw]

@Lonnie.Cady

By the looks of your screenshots it's only a graphics issue.

Because the path is still about the same length, so it starts the drilling not that much sooner. 

[Lonnie.Cady]

@Laurens-3DTechDraw by the looks of the screen shots????  So you never looked at it???  I see a difference of .7334"

The graphical representation is also wrong.  One show a green feed move and the other a yellow rapid for the feed portion.

(Machining from Z+ G17)
G17
G0 Z0.7034
X0.
Z0.8034
G81 X0. Z-2.2922 R0.8034 F0.012

(Machining from Z+ G17)
G17
G0 Z0.65
X0.
Z0.25
G81 X0. Z-2.2922 R0.07 F0.012

[Laurens-3DTechDraw]

@Lonnie.Cady

I'm sorry I assumed that it would have made the retract height higher as well when it makes the top higher.

But that depends on the other height selections of course.

And no I didn't look at the file because the **** fusion always needs to update. So it takes 5 years before I can actually look at a file.

[Lonnie.Cady]

@Laurens-3DTechDraw the chamfer is only .03" in the bore.  I just used auto merge to pick up the chamfer.

I agree the last update seemed to require a few updates.

[Laurens-3DTechDraw]

Yeah.

I would have expected this if it made the hole longer:

Because of that, I assumed it was just a graphical mis-presentation fo the hole height.

Also hard to see because the line isn't always different colored for the feed vs rapid moves.

[paul.clauss · Accepted solution]

Hi @Lonnie.Cady, @Laurens-3DTechDraw, @Steinwerks

Thanks for posting! I was able to reproduce some unpredictable behavior in both the file attached to the original post in this thread as well as in a new file. It appears that the cutting heights seem to be somewhat unpredictable when three variables are present in the model and drilling operation setup;

• the unpredictable heights only occurred when the chamfers were present in the design,
• the "Auto-Merge Hole Segments" flag is enabled,
• the top and/or bottom heights are defined as "Hole Top" or "Hole Bottom."

In your file I noticed the extra drilling length was added to the top of the hole - when I recreated your exact geometry and drilling operation in a new file the extra drilling length was added to the bottom of the hole!

From my tests, I believe this is an issue in which using "Hole Top" and "Hole Bottom" as the height definitions is causing problems - if you select anything else for the heights (model or stock tops and bottoms or geometry selections), then enabling the "Auto-Merge Hole Segments" flag no longer extends the drilling depth. As I believe this is a problem with the way Fusion is seeing heights defined by the hole geometry, I have logged an issue (CAM-8169) with development. We appreciate you bringing this to our attention!

While this is addressed, using any other height definitions than "Hole top" and "Hole bottom" to define the top and bottom heights of the cut should allow you to work around this unpredictable behavior. Please let me know if you have any questions - I am happy to help.

[Lonnie.Cady]

@paul.clauss

Thank you for looking into this and getting this reported.