Containment boundaries don't work right?

[Bob W.]

I am creating a 3D HST pencil toolpath and it took no less than 20 containment boundaries to get it to produce FAIRLY good results. The containment was set to tool center yet there was still machining being done that violated these boundaries. This was not related to the arc entry/exit, but actual surfaces being machined. Only after a bunch of hocus pocus, offsetting contours, and about 20 regenerations did I finally get a good toolpath. I don't think I am doing anything wrong but if there is a better way I'd love to hear about it.

 

CNC, if you guys could fix this it would have saved me about 30-40 minutes on this toolpath alone and it would be a tangible gain for my maintenance $$$ spent. It would be great if when I specify a containment boundary and set it to tool center it actually works the way it should. This has been an issue for a LONG time.

 

Thanks,

Bob

[MikronGuy]

+10000 Bob

[Bob W.]

Also, this is exactly why I still use the old style surfacing toolpaths on a regular basis. There is so much less drama and headache required to get good results. It would be great if the day came where the HST surfacing toolpaths were equally as drama free. They do regenerate much faster though, kudos for that. I now find out it isn't working right in a fraction of the time, LOL!

[acam]

I have also taken some time to examine this issue.

 

Mastercam has a C-hook called CreateBoundary.dll, which should create the necessary boundary:

 

 

This Chook has never created correct boundaries which could be used as a tool contact point boundaries.

 

I attached a MCX file which shows as a nice example of this issue:

 

 

it would be really great if HST would be able to utilize such boundaries.

 

Regards

CREATE BOUNDARY BUG - SECOND EXAMPLE-1.MCX-7

[Bob W.]

I see what you are saying and it is really cool, but this isn't a contact point issue. The tool is simply violating the boundary. The center of the tool is violating the boundary and machining the surfaces within this boundary, which is being used as a keep out zone.

[Redfire427]

That create boundary C-hook is one step ahead of "useless". The boundaries it creates are fairly inaccurate, not to mention very rough. Hard to believe, given modern computing power. The HST pencil tool path takes a ton of tweaking before you get anything acceptable. I've just learned to live with it.

 

Carmen

[Mick]

I've been talking about this for ages. The option of roll tool at all edges, between surfaces, or automatic worked great. The tool, if necessary would cut to the tangential contact point, and no more or less when finishing. I used to get fantastic results. That is the main reason why I shy away from the new toolpaths. Containment boundaries are a band aid approach in some cases, as the surface should drive the tool position.

 

It is kind of tiring, this "give some but take some" with the newer versions

[Guest]

I just sent something CNC regarding this very "feature". O, the skinny is that the boundary is not a containment boundary on the HST toolpaths but instead is a material boundary meaning that it will machine all down it.

 

So, knowing that, I'm going o request that the toolpath have a switch, keep it as is or use it as a contain boundary.

 

I know it doesn't help but just thought I would share.

[Bob W.]

Sure wish they would label it something other than "containment boundary" then. It is a little misleading. How is one to keep the tool away from features they don't want to machine with these HST toolpaths then? It is a real pain and something needs to be done about it. There is so much tribal knowledge involved in making these really sing it is ridiculous.

 

Interesting thing is that in this project it is behaving exactly like a containment boundary everywhere except this one spot and offsetting the boundary by .01" made it work.

[Newbeeee™]

It would be REALLY sweet if a 'fools guide' was produced by cnc for these paths. Similar to what MCM produced a while ago would be brilliant - a pdf style booklet with pics of example shapes/parts and why and how to use this path over another path..

I'm doing a project now with a load of scanning/ramped faces into faces and was struggling yesterday funnily enough on the new toolpaths. In the end I tried the old and bingo - should have done it earlier.

The roughing HS toolpaths are so sweet that I go there 1st call everytime without thinking.

The finishing HS toolpaths however never work for me without a lot of fiddling - I always go there first as it seems the right thing to do because they're new, but I always seem to be going back to flowline and surface finish contour which usually work for me straight away.

[cobra95kev]

I use the multi-axis toolpaths a lot for surfacing operations, much much greater control over check surface controls.

Just lock it down to 3-axis. But I agree a lot of this stuff needs fixed.

 

Kevin C.

[Peter - Avivi CNC Solutions]

I use the multi-axis toolpaths a lot for surfacing operations, much much greater control over check surface controls.

 

+1

[Hertz]

I agree with OP. I tend to shy away from the HST as well. Little things like that frustrate me too. Same as having to put a number into the check surfaces to keep the tool off. What is the point of a check surface if you have to leave material in the box for it to work? Check surface is the surfaces to NOT machine is it not?