entry position "trace"

[marco.bazzali]

Hi,
I have to make a chamfer in a Ø1 hole, inside a cylinder. I tried to use the "trace" path, it seems to be correct.
But I can't figure out how to start it from the center as an entry point.

Thanks

[DarthBane55]

With trace, the tool follows edges or sketches, exactly.  The only option for lead-in/out is a vertical radius.  So if you want to use trace for this, draw a sketch with your lead-in included, it will then do exactly what you want.  That path is useful for cases where you need a tool to do exactly the motions you want, or self intersecting toolpaths (2d contour cannot self intersect), and some other particular cases.

[marco.bazzali]

thanks for answering me.
I did what you told me, I created a line, it works, the only problem is that it doesn't recognize it as a single path.

[DarthBane55]

I forgot to mention that your sketch should include the entire toolpath, not just the lead-in.  It has to be 1 continuous sketch for it to follow it in 1 toolpath.  Also, I believe it should be an opened sketch, so for the circle doing the actual chamfer, break the circle with a tiny little gap, like 0.0001", then draw the lead out if you want one, otherwise it will stop right there.  If you need me to do it in your file and repost it here I can do that.

[marco.bazzali]

hi DarthBane55,thank you very much,being still at the first steps with fusion, for me it is very complicated to perform this piece.I ask you the courtesy if you can see how I can solve this problem, in attachment I send you the piece file.
Thank you and good day

[DarthBane55]

Ok, it proved a bit more tricky than I anticipated.  Didn't realize the chamfer was in 3d until I saw the file...

So attached is the result.  If someone sees a better, simpler way to do this, please speak up, this is time consuming for sure.

Anyways, so what I did is I created a surface with 0 offset of the hole, then I created another surface (look at the surface bodies I created), to split that 1st surface by a very small amount, in order to be able to add the lead-in and lead-out.  Then I offset that split surface, in order to have it represent where the centerline of the tool should be, because if you use "left" or "right", you can't draw a lead-in, as this left or right would also be applied to the drawn lead-in/out.  So you must use "center" in the toolpath parameter.  Then I created a 3d sketch to add the lead-in/out, going to the center of the hole.

Have a look at the file, hopefully you'll make sense of it, but I think it creates a beautiful chamfer under the hole...!

[marco.bazzali]

I am very grateful for the help you have given me.
I wish you a good continuation

marco

[marco.bazzali]

Hi, DarthBane55, sorry to bother you. I wanted to ask you one more question.
I tried to replicate what you did and, I arrived when you created the sketch of the two semicircles in the center of the piece.
I'm just missing the last sketch, where the two lines are inside the smaller hole.
Can you explain how to do that?
Thank you very much

[marco.bazzali]

Hi, DarthBane55, sorry to bother you. I wanted to ask you one more question.
I tried to replicate what you did and, I arrived when you created the sketch of the two semicircles in the center of the piece.
I'm just missing the last sketch, where the two lines are inside the smaller hole.
Can you explain how to do that?
Thank you very much

[marco.bazzali]

Hi, DarthBane55, sorry to bother you. I wanted to ask you one more question.
I tried to replicate what you did and, I arrived when you created the sketch of the two semicircles in the center of the piece.
I'm just missing the last sketch, where the two lines are inside the smaller hole.
Can you explain how to do that?
Thank you very much

[DarthBane55]

ok, for that sketch, you need to activate 3d sketch.  You can't really create a plane and do a 2d sketch, because you see, where the split is in the surface, that causes the height to be different by juuuuust a little bit (because the surface is 3d).  It is important for these lines to be connected to the bottom edge of the surface, so a plane would only allow you to do 1 of the 2 lines.  I think that maybe you could create a 2nd plane for the 2nd line, but that seems like a waste of time.

So when you click sketch, choose the origin plane XZ, this will set the general orientation of the sketch.

Then, on the sketch palette window that pops up, the last item at the bottom is "3D sketch".  Check that box.

Then you can draw lines connected to the endpoints of the surface even if they are not on the same planar level.  To reach the exact center of the hole, I have another 2d sketch done that you can see, on the same XZ plane, and projected the hole on it, and in this case I had to draw a line across the hole, and a point in the middle of that line, to get the center of the hole.  Not sure why, sometimes projecting a hole results in a circle with the center point already included, but anyway, this worked.  So in the 3d sketch, you start the line from one endpoint on the surface, to the center point of the hole, and repeat for the other endpoint of the surface.

Since these 2 lines are now connected to the surface, in your operation you can select the line, click it again to add elements to your selection, and pick the bottom edge of the surface and the other line (lead-out).

That should do it...  I hope you can make sense of this explanation...