Wrong Tip offset / Simulation (Form Mill)

[FTKnur]

The tip offset from a "Form Mill" does not work correctly IMO.

Tool: Double-Chamfer

Selected contour

False contour by "Bottom Height: Selected contours"

Selected Contours: But the simulation is correct ... the NC-Code/calculation is wrong

By selecting the Height "selected contours" it should look like this

This is by selecting the height "Model Top"

Now the simulation is not correct ...

 Right contour but false simulation

Besides the heights "Selected Contour" and "Model Top" should be the same in this case. But I get 2 different results? 😕

Or did I something wrong?

In the .ipt you see what I mean.

Hope you can help 🙂

[Matthew-R]

@FTKnur Thank you for posting this issue to the forum and my apologies that the tool isn't working quite right for you. I've taken your detailed account of this issue and reported it to our development team for further investigation. The reference number of this report with them is CAM-9331. We will reach out to you on this forum thread if we have any additional questions and we will also provide you with updates through this forum thread. Thanks again and we'll be in touch soon. 

[angelo.juras]

Hello @FTKnur, thank you for reaching out to us here. The tool you want to use for this is a Chamfer mill along with our 2D Chamfer toolpath. I attached the file so you can see what I did.

You can then make adjustments on the Passes tab to suit your needs and also update the tool dimensions to match your cutting tool.

[FTKnur]

Hello,

thank you for reply.

With my tool I want to burr at the same time the bottom side. (Double Chamfer Mill)

E.g.

https://www.hoffmann-group.com/US/en/hus/Modular-machining/Indexable-milling-cutters-GARANT/High-per...

1 Job for the upper side and 1 for the bottom side (just change the "Stock to leave").

With 2D-Chamfer I don't get it to work on the bottom side 😕

The tool in the machine is measured on the theorethical cusp (maximum diameter how in the picture in my post before).

With my selfmade tool it works (but not correcly):

 Right contour - simulation wrong - bottom height (IMO also wrong)

 Wrong Contour - simulation right - selected contour (IMO right but dosn't work)

Have 2 more jobs added to the file.

Perhaps there is a complete other way but I don't see it 😞

[keith.clausen]

This all looks correct when using and defining a form tool. I totally get what you are trying to do in the sense of defining your chamfer mill as a form tool so that you can back chamfer with it. I do it all the time.

What operation type are you using. The correct one would be 2D Contour. You will not be able to use the chamfer parameters. To adjust for chamfer size and tip offset adjust the radial & axial stock to leave appropriately.  

[keith.clausen]

Remember when using form tools. The defined point in the form tool and the drive edge selected are coincident. the simulation on the other hand is intended to simulate using the bottom center of the tool. So in your images this look as it should be.

[FTKnur]

I think the tip offset should just do a change in the simulation and not the contour.

Why I should use the tip offset when it changes afterwards my Contour. I want to mill a contour and the simulation just work to it.

I use 2D-Contour for chamfers.

How it's look now:

Please look again to the picture with the point I set with Diameter/Tip offset:

This is the Contour that I want

E.g. Diameter: 50mm

       Depth: 30mm

Contour:  Diameter: 51.5mm

                Depth: 30.5mm

Now it should mill a chamfer from 0.25mm x 45°

This looks now:

Should look like:

Why can I use the tip offset when it doesn't change the simulation to my Contour. Now it changes the Contour but this is not the right way.

To change the contour I use axial/radial stock to leave.

You say the points are coincident but the simulation use the Bottom. It's for me an contradiction.

Eventually I do something fundamental wrong. Or there is an other way to mill the chamfer.

The Main problem is that I can make the right contour to mill the chamfer but don't get the right simulation to this!

Cant check it with the simulation 😞

 Edit:

I found this (it's in German) but there is the same problem that I have.

https://forums.autodesk.com/t5/hsm-ideas/formfraser-z-hohe-soll-identisch-mit-konstruktionspunkt/idc...

That is the same problem just little bit different explained.

He set the point in the middle of the radius and HSM simulate it right when selected contours is used. But the NC-Code is wrong (blue line).

HSM changed the NC-Code to the bottom of the tool. Thats not convenient.

[keith.clausen]

Ok, while I'm not an InventorHSM guy the toolpath fundamentals are the same for the most part. I created a few examples in your file that is attached and it all look fine and seems to be working as it should. Of course it would have been helpful to know that you are using comp in control, but in either case it will work fine.

If you code doesn't look correct that it is the post. remember that bottom of the tool is still always the bottom of the tool. What I mean by that is that regardless of where you place the drive point when creating the form tool the bottom is still the bottom. When you do the tool length offset on the machine it is using the bottom of the tool not an adjustment to the drive point. You may know this already but it is always worth mentioning as I've seen others get tripped up by this when they are trying to wrap their heads around this. 

Does that make sense?