topic pattern in a a 3d offset strategy in PowerMill Forum

pattern in a a 3d offset strategy

psx2 — Mon, 14 Nov 2016 09:00:21 GMT

hi,

i don't undestand the usefulness of a pattern in a 3d offset stgrategy.

In my example i need to create a 3d offset that goes from inside to outside.

the files have the same options

without_Pattern

with_pattern

with_pattern_begin_on_pattern

Option

in the first file the toolpath don't goes from inside to outside and the junction go to the outside !!

in the second the toolpath is almost as good ( why there isn't only one junction ? )

in the third the last junction go outside !!!

PS: the pattern is the same of the external boundary

Thanks

Re: pattern in a a 3d offset strategy

psx2 — Tue, 15 Nov 2016 12:50:54 GMT

i've saw that to have a correct toolpath i must select " start on pattern " option but anyway i don't know where it approach .... sometimes in adn sometimes out !!!!! But if i select " from inside " option i want approach IN avery time !!!!

this for me it's a great problem !!!

Any suggestion ?

Thanks

Re: pattern in a a 3d offset strategy

ctlong2002 — Tue, 29 Nov 2016 08:36:08 GMT

1.Select pattern that you want to machine

2. Limit by the boundary (select outside)

Re: pattern in a a 3d offset strategy

ctlong2002 — Thu, 01 Dec 2016 03:42:04 GMT

If you create a pattern in the middle of boundary(approximately) like image.

And select the pattern .

Limit by boundary.

Re: pattern in a a 3d offset strategy

Anonymous — Thu, 01 Dec 2016 06:35:34 GMT

Hi psx2,

i think your problem is that you have an pattern at the inside AND the outside of the boundary. If you want to machine from the inside to the outside you only need the pattern inside otherwise it will machine one half from the inside and the other half from the outside. (see attached files)

Re: pattern in a a 3d offset strategy

psx2 — Thu, 01 Dec 2016 20:40:57 GMT

Thanks to all...
For feuerbowle:
Yes only inside pattern but in this way at the end of toolpath ( outside ) the toolpath does not coincide with boundary !!
Because ?

Re: pattern in a a 3d offset strategy

ctlong2002 — Fri, 02 Dec 2016 01:21:03 GMT

If you want to coincide the toolpath with boundary!Select the method "Parametric Offset Finishing" is better!Just select the "start pattern" and "end pattern" , and it will make better smooth toolpath."Start pattern" and "End pattern " will decide the direction of toolpath (inside >> outside or outside >> inside)

Re: pattern in a a 3d offset strategy

psx2 — Fri, 02 Dec 2016 09:08:11 GMT

yes, i know but i've the need to use 3d offset !

thanks

Re: pattern in a a 3d offset strategy

Mike_Caliguri — Tue, 06 Dec 2016 16:25:19 GMT

i don't undestand the usefulness of a pattern in a 3d offset stgrategy.

In my example i need to create a 3d offset that goes from inside to outside."

So to me this is two questions

1)I don't understand the usefulness of a pattern in a 3D offset strategy

2)In my example i need to create a 3D offset that goes from inside to outside

2) I will answer the second one first. In PowerMILL 2017 there is a new control to start outside, so I am assuming you are using an older version. The easiest thing is to simply do a "reorder". So you create the toolpath like normal (with or without a pattern see answer one) and it is starting outside as it always does with 3D offset. So you Right click on the toolpath and select EDIT then REORDER then in the reorder dialog select REVERSE ORDER. This will take the toolpath and change it from inside to outside. As a tech tip you may need to create the original as a conventional cut so when you reorder it it converts to climb if that is a factor. Easy as pie and no need to recalculate the toolpath. BTW this works on almost every strategy if needed

1) So the second question is what are patterns used for? This is a more abstract use and probably not used very often depending on what you are doing. Typically when using 3D offset you have a boundary and the toolpath starts on the boundary and collapses in a 3D offset manner, as you expect. What a pattern allows you to do is to direct the toolpath to follow a different cut direction or offset rather than simply using the boundary. Like a middle out approach, or typically using "open" offsets versus the "closed" offsets you typically get. Hopefully that answers that.

Re: pattern in a a 3d offset strategy

ewshp — Thu, 08 Dec 2016 14:59:52 GMT

@Anonymous wrote:
"
i don't undestand the usefulness of a pattern in a 3d offset stgrategy.
In my example i need to create a 3d offset that goes from inside to outside."

So to me this is two questions
1)I don't understand the usefulness of a pattern in a 3D offset strategy
2)In my example i need to create a 3D offset that goes from inside to outside

2) The thing 3D Offset toolpaths in pre-2017 version is that i you have checked the spiral option, reversing it will break the spiral and add links to every steps of the 3D Offset. Keep that in mind as if you use an arc approach and an arc link between toolpaths segments, you will propably end up with some marks on the part. The new starting point option is very useful in this case (regular and uninterupted spiral in the right direction)

1) I use patterns in 3D Offset and parametric 3D Offset to direct the cut on the part as most of the metal parts i mill need mirror polishing afterwards.
It makes the polishing job easier when cut is flowing along nicely (less grit to manage and less time in the end).

Hope this helps.

Re: pattern in a a 3d offset strategy

psx2 — Thu, 08 Dec 2016 15:33:53 GMT

thanks to all !!!
Sorry but i speak english a little !!

i use pm 2017 but in my sample if i use oly 4 boundary and selec from inside to outside the toolpath start at centre of two boundary !!!!!!!

i don't know why !!!!

See image