TOOL BREAKAGE ON DYNAMIC 2D FOR SOME SHAPES

[lowcountrycamo]

When I use dynamic 2d to mill (face) rectangular shapes from outside I get tool breakage near the center when the tool takes the corner. I attached a pic of what I am referring to.  Has anyone ever come up with a way to avoid this?  I wish I could make the tool go past before making the turn, when approaching the center of the path.

   

[huskermcdoogle]

I have had to chain an island before, then cut it off with a separate path in a few depth cuts.  But for me, it usually isn't for tool breakage, but rather the island breaking off below the facing surface.

[jeff]

Haven't found a workaround for it yet. Has it been logged yet?

[huskermcdoogle]

12 minutes ago, jeff said:

Haven't found a workaround for it yet. Has it been logged yet?

I would hope so by now, it seems to be an issue with all square outside shapes, especially on the first pass.

[JoshC]

I know a while back i sent up an enhancement request to cnc software about this and I am pretty sure they logged it as an enhancement or something, How i got around it was splitting that long length of material into two smaller sections and using two operations instead of one. 

basically split that machining region into two smaller ones, cut the one region while avoiding the other for the first toolpath. then for the second toolpath cut the other side and pick the already cut area as an air region.  by dividing the machining region in half and doing 2 operations it wont be as lengthy and will likely not have any sliver of material left behind. that should work nicely but let me know if it doesn't make sense and i can make an example file if needed.

 

[SpacePilotPro]

I have also broken tools on few occasions with this exact problem. When the rib gets torn off, if it doesn't damage the tool sometimes it will tear a little chunk of material out of the face with it.

[crazy^millman]

There is a long conversation about this between me and the product manager. Really comes down to many factors and material and how it will respond to slivers is not part of the algorithm. What I have had to do on these occasions is switch things up and change the process all together to get away from these slivers. As they work to the center you will see this, but if they work to an edge they will not do the same thing. When working to an edge the natural of the stock and not keep strength in a way to do this. Another thing to do is to make a fin in your part that gives you the ability to control how thick you have a piece to end up with. either way it comes down to the programmer to think for the software since the software cannot take all of these different things into account.

What do I mean by a fin. When in the top example a 1/4 wide fin by 4" long would have been okay to leave. Then come back and center cut that fin off with a different approach. Think for the cut and not let it go to it's own process. Metal has plasticity meaning guess what it can bend and move and do all kind of things and guess what the thinner you make it the more this becomes and issue. Softer material will do this and not break you tool were hard material with more capability to hold on to the sliver will. Nature of the beast and you have to think for the process and control your own density.  When you start doing 200% depths you see this more and more you back down to 50% depths of cuts you don't see this. Again really comes down to your approach and your process. Make shapes to break up the creation of sliver they are easy to remove, but still give you the benefit of what you need. In all reality that is what is missing from the process is stock evaluation of the material as it is being removed. There needed to be constant cross section analysis of the material being removed and and full analysis of the material you are cutting to see what it yields and characteristics are for what is material that will effect the cutter in certain conditions. That is not being considered and where the technology as a whole needs to change. The missing element is full FEA (Finite Element Analysis) of the cut and cutting process not just a look at the rough stock and finish part and get the material off of it. A full evaluation of each cut, each condition and where will the possible issues come up will have to be added to HST machining and this process as a whole. Great stuff and have not sure surface rough pocket in 5 or 6 years, but when you flip the world on it head you have then see what happened when you do that. Here the process is in all reality flipped the manufacturing work on its head and these areas were the technology will have to mature and change to address these issues for the customer. 5% of my projects are effected by this issue so I am aware of the issue and adjust for it where needed.

Sorry, but crazy guy talk.