5-axis deburr touching faces

[DarthBane55]

Hi, how do I control how far the tool stays from the faces beside the chamfers?

Right now, the tool touches (becomes tangent) with adjacent faces, which of course renders this not usable.  There has to be a way to control the distance to faces... I can't find it 😞

You can see when deburring the top edge, the tool touches that fillet, which is bogus.  I tried picking the fillet as a check surface, but then it doesn't deburr the fillet from it's own sharp edge (see below).

Seems illogical that there is no setting to avoid touching the side faces...  please help!

Thank you!

PS: I cannot share this file but I am just after a setting here, I think the pictures show the issue.

[kacper.suchomski]

Hi

I don't have access to the Deburr strategy, but the Chamfer strategy has a Chamfer Clearance entry on the Passes tab.

You might want to check if you have something similar available.

[DarthBane55]

Unfortunately, for "Deburr" there is no such setting.  I tried using a chamfermill instead of a ballmill to see if the setting would appear, but nope.  I guess this is making this toolpath completely unusable, which is rather unfortunate, it's one of the main reasons I bought the extensions...

I'm waiting for someone who actually has the answer, positive or negative.  Autodesk I welcome your advice on how to use this amazing operation properly without touching adjacent faces.

[DarthBane55]

After testing some stuff, I see that the clearance is dictated by the "shoulder clearance" on the tool tab.  So for a ballmill, that'll never work because the tool tilts (5-axis deburring), so the shoulder is always away from the surfaces, which means the ball (cutting edge) will always touch adjacent surfaces.  So it would have to be broken up in multiple operations, and adding check surfaces as needed.  Which negates the benefit of automatic deburring.

For chamfermills, I see why it failed for me (same shoulder reason as the ballmill).  See pictures below, this chamfer mill has a longer flute, so the shoulder would never come close to any walls on this part, therefore, shoulder clearance does nothing at all.  By cheating, and defining the tool wrongly (not as manufactured), and making the shoulder shorter, it works.  So I'll have to cheat all my tools for this to work.

That being said, when using 2d chamfering, it clears the adjacent walls by a number you give it, regardless of shoulder length and whatnot.  It just works.  So, Deburr is a regression in this regard.  It's still a great toolpath but I see many issues with it impeding it's "automatic deburring" vocation.  It should behave more like the 2d chamfering for staying away from walls.

 Flute is long, shoulder is not affecting the clearance distance (bad).

 Flute is shorter (but not as manufactured, so have to cheat all my tools), shoulder clearance distance is respected.

[DarthBane55]

Oh I forgot, we are forced to add a 25% of tool diameter lead, which shortens the chamfer nearness to walls (tool going away from edge by that lead radius).  I cannot see any logical explanation to force us, the programmers, who's job is to program, not the software (not yet anyways lol...).  We should decide whatever lead we want.  Who decided that a 25% lead is required?????  Sometimes these decisions are so frustrating it's not even funny.  You, the autodesk computer programmer, cannot decide what lead-in/out I the CNC programmer want.  Why would you put this restriction in?  Come on!!!!  Even if you think it makes the entry and exit smooth, it is not your decision!!!

[a.laasW8M6T]

Hi

I cannot see any parameters for avoiding faces by an amount, there may be a trick to it that I do not know.

I haven't had  issues like this with this toolpath before, but obviously haven't had that particular combination of geometry.

As for the lead in thing, The toolpath is Licensed from Moduleworks so I don't know how much control Autodesk has over that part of the toolpath

[UTD7ZNYB]

There are no parameters to control it, but if there’s an area you absolutely don’t want the tool to touch, there are several ways to handle it.

It should work if you create an auxiliary surface on the marked area and set it as an Avoid Surface.

[DarthBane55]

Right, and that saves times compared to normal chamfer how exactly?  I thought the goal of this was to automatically deburr a part with minimal effort.  If I have to make surfaces to make it work, I'll stick to normal chamfering, that's easier.

Now, I can make it work, I did a combination of deburr and chamfer operations on this part.  I ended up using deburr contained to 3-axis, which took care of most sharp edges, then excluded some problematic edges and used chamfer op on those.  I think maybe my hopes were too high on this toolpath, but still, I don't think the ballmill should be touching the adjacent faces, it makes no sense to touch those when you deburr, nobody would do that, you'd see it on the end result.  Anyway, it's semi working, semi saving time, but I would not call it automatic deburr at this point.  It is not called that, I know... I made that up probably.  But videos show this as the holy grail of deburring, which it is maybe in some specific geometric conditions, but it has to be perfect I guess.  Anyway, beating on this further will not improve it lol.

[UTD7ZNYB]

I agree that this strategy has some issues.
However, I also think that not many people are overly concerned if the tool lightly touches an adjacent edge during deburring. When you deburr with a file, it’s quite common to accidentally hit the neighboring edge, right?
As another workaround, how about setting the tool diameter slightly larger than the actual size and increasing the deburring allowance accordingly? That way, you can avoid the unwanted contact without adding extra steps.

[DarthBane55]

Sorry, our customers are quite demanding, any visual defect is not acceptable.  If we end up having to file an edge, it is done with extreme care.

Cheating the tool, hmmmmmm, I could try that...  I don't think it would track perfectly in 5 axis though, specially on inside corners where it does a loop to get to the corner, and the simulation wouldn't look accurate, but it might work for some stuff, worth a shot, thanks for the idea.  

[djtlumic]

Similar problem here. 2d chamfer , various leads and clearence, but still touching face on leads. Do you have some advice? Thank you

[programming2C78B]

^ that island is a 3D feature. Its beyond the scope of a 2D chamfer toolpath. 
Just remove that inside corner from your contour selection.

[djtlumic]

Strategy is aware of that island, it comes with perfect touch with many setting variations and preventing touching islands should be basic for clearence setting in chamfer strategy. Unfortunately remove inside corner from selection isnt solution, i need to chamfer it and many other similar geometries. THX

[DarthBane55]

I think the leads are not included in the clearance... usually in a case like yours I do a lead-in/out with 0 radius and angle 110 (just so that when it plunges down it's not that close to the wall, more of a "scare factor" than a necessity.  Then the clearance is fine because you are not adding the lead into the mix.

[lauri_barnhart]

Hello, @DarthBane55,

Did the information provided by @kacper.suchomski, @a.laasW8M6T, @UTD7ZNYB or @djtlumic help you and answer your question?

If yes, please click on the "Accept Solution" button on the post(s) that solved your problem. This will assist other community users in finding and benefiting from this information.

If not, please do not hesitate to give an update in this thread so all community members receive an update on the progression of your question, and can suggest next steps that may be helpful for you to achieve what you're looking for.

All the best,

Lauri | Community Manager

[DarthBane55]

If you mean that it confirmed that this cycle will not avoid touching adjacent faces, sure.  I wouldn't call it resolved as a deburring process should never touch adjacent faces.

[djtlumic]

I found that too, but i see no reason why leads are not (fully) included for clearence. They are included for collisions but with zero setting for clearence. Minor tweak would make this strategy much better, i hope someone from autodesk is reading this.
Making zero leads is anoying and not got for machines. So my default is leads for all operation.

[CRANDALLPRECISION]

Could you call the tool .003 bigger than what it is? I usually find that the feature it bumped into actually has stock left on it from deflection ect. and that is why it contacted. Module Works toolpath so Autodesk probably has no control over it. Same as the rest of the companies leasing their toolpaths.

[seth.madore]

@DarthBane55 any chance you could share a sample file that demonstrates this issue? If there's room for improvement, I'd like to get this logged and at least investigated.

[DarthBane55]

@seth.madore 

I cannot share a customer file, but I can easily rebuild a similar one that would cause the issue.  I don't think it will be today, but I will do it when I get a minute for sure, thanks!