Up Against a Wall

[Holomon]

I am having a little difficulty with parallel surfacing inside of a cavity. When the tool feeds up against a wall it usually stops about .002" short of the wall. I am not using a containment boundary. Usually I can work around this problem but would really like to find out what I am doing wrong or if anyone else has encountered this.

 

[ 03-25-2004, 03:18 PM: Message edited by: holomon ]

[Jayson Kramer]

well are you using a check surface?

 

Are you telling it to stay at a depth?

[Quickmike]

If possible put it up onthe ftp and I' sure someone will be able to help.

[Holomon]

I'm not using a check surface but have added a containment boundary. The tool will stop .0023 short of the wall face.

[Holomon]

I have put it on the FTP site(AGAINSTWALL.MC9)..Many Thanks to all..

[crazy^millman]

Not looking at the file can you use flowline for the Part?

[Holomon]

This case doesn't seem like a good candidate for Flowline..

[Chris Rizzo]

Took a quick look at her....could be something with containment boundry. If you set it to outside, too will totally climb the wall. I was just playing with entering negative values then to get it to kiss the wall, but not climb it.

 

-or maybe make boundry bigger and add check surfaces as top of boss? Just a thought.

 

Oh, my cycles over..gotta go.

[Holomon]

Thanks to everyone for the sugestions. There are many ways to work around the problem but I would like to know if I'm missing something. Does anyone else have any problems getting toolpath to go all the way up against a wall with parallel surfacing?..Thanks again..

[Code_Breaker]

Holomon,

 

I can't get to the FTP site (we have a firewall in place), so could you zip it and e-mail it to me?

 

Thanks

Code_Breaker

[Holomon]

Code_Breaker,

If you can send me your address I will send you the zipped file..

[SledGeek]

Did you enter any values in the boundary offset box ?

[Holomon]

Yes..I have tried negative values as well..I have had this problem on many different parts..

[Chris Rizzo]

I'm thinking "outside the box" (pun) a bit on this one....how do you determine that the cut stops .002 away from that wall? Could the wall be .002 "overcut" instead, and thus offset from your surface?

Tool undersize? Machine offset correct? Grasping at straws here!

 

Maybe backplot and save the toolpath as geometry, and check the resultant toolpath centerline distance from the wall....? Just some ideas.

[Thad]

Is it just because of your stepover direction? The total distance to be cut isn't divisible by your stepover. So it gets "as close at it can." What do you get if you cut 90 degrees to your current toolpath?

 

Just a thought.

 

Thad

[SledGeek]

Good thought cmr, that's usually the stuff that keeps ya thinkin'.

 

If it happens frequently, it possible that it's the same tool and you have a wear offset set in the machine for that same tool?

[SledGeek]

Did as Thad suggested and it works fine. If you don't like that way, you can take off last .0023 with a flowline path using check surfaces.

 

Good luck

[cadcam]

Take it and change te cut to .001 it goes right to the wall.

It is the step over.

[Müřlıń®]

What is your cut tolerance and filter tolerance set to?

 

 

Murlin

[Holomon]

I did a backplot and saved as toolpath to determine the .0023 distance..When the cut direction is rotated 90 degrees the toolpath WILL go all the way to the wall but this approach will force the tool to plunge into a heavy cut(corner) rather than working into the cut..My cut and filter tolerance is set to .0002..I will just add a flowline path to finish the feature..Thanks to all for taking the time to respond..This forum is a very valuable tool!

[Thad]

quote:

---

When the cut direction is rotated 90 degrees the toolpath WILL go all the way to the wall but this approach will force the tool to plunge into a heavy cut(corner) rather than working into the cut.

---

Even if you select a start point?

 

Thad

[Holomon]

Thad,

This feature has 3 walls and is open on one end therefore it has a corner on two sides..Selecting a start point will only let me move the heavy cut from one side to the other..

 

Holomon

[mross]

I had the same problem once, and I found it to be my stepover amount.

 

Try and decrease it to see if that works.

 

HTH

[Thad]

Perhaps more effective roughing paths would've helped. Just throwing ideas at you. Sounds like you've got it taken care of anyway.

 

Thad

[Holomon]

Thad,

I did work around the problem..Thanks again to all..

 

Holomon