Wire EDM Problem's

[weirdharold]

I have two objective's. To learn NX5 Wire & to modify A generic 4 Axis post with Post Builder . First problem is , I have my "dummy" part with 5 deg. draft. I go into Open Profile , Chain my lower & upper boundries & then verify. My little wire "tool" goes around profile once, & flip's upsidedown & now profiles the under side of my part. What in the world am I doing wrong ??
Thank's for any help in advance .
Harold C.

[1 Infinite Loop]

I have not used NX wedm much but maybe we can figure your problem out. From the image it looks like you have a solid part. When I have programmed wedm for parts with taper, I use 4-axis and select faces not edge chains. You can use edges on solids, surfaces and wire frame geometry but I find that selecting faces is much more safe to use. Even on 2-d wedm paths I tend to use a 4-axis operation just so I can select faces then post with my 4-axis post. The 2-D nc output is fine, there are not any U-V moves in the file.

As for the "flipping" in your path, I have not seen this before but perhaps the chain has more edges than you need. Make sure you are chaining just a single edge and not up any vertical edges or chaining a loop, just as you would create a planar mill profile. 2-D wedm programming is actually similar to simple 2-D milling programming, nothing more. Give that a shot and see what happens to your output. Also, perhaps try using 4-axis for the Axis Type when selecting your geometry and try selecting faces rather than edges. At any rate you are going to need a working post. You mentioned editing a generic post so I assume you are going to start with a generic post in PB. Don't use the default ISO post that ships with NX if you are going to program for typical wedm's such as a Fanuc or Makino; the U-V output is not the correct format.

Have you used Post Builder before? It can be a bit daunting to a casual user and you should really have some training on how to use it, at least from another user. IMO it is not something a fellow forum poster can walk you through. Do you have support? If your support with Siemens is active you can download posts from their support site. If not then perhaps one of us could help you locate a basic post.

[weirdharold]

Thank's for the help, Jim. Went back & reselected faces & does not flip now but get error saying ( non-linear side detected! This may cause gouge near the edge. ) Seem's to verify OK. But our real problem is the output code. I'm going to attach the code we get from NX, with generic post, & code programed with another Cam system, which is what we want. I would like to know if this is possible in NX5 before I continue with this project. Long story. We have 3 Fanuc Series 180 iS-WB EDM's. My thing normally are mill's but we are getting more wire work so I have been elected wire man also on my shift. I work night's. I do have some exposure to Post- Builder but not a great deal. I learn much of what I know through online training, Help doc's & just doing it. One machinist has a username & web-key # but it's no longer valid. He's in the process of trying to get another. so that's where we stand.


Regard's,
Harold C.




( Code was produced from part pictured in my first post )


(Had wrong NX5 code listed. This is code you get with wire post shipped with NX5 unmodified)

[1 Infinite Loop]

The error message you are getting is probably because it is seeing the path as not able cut. You probably know you can only cut flat, cylindrical and conical faces. Even a cylindrical or conical face can have issues if there are other faces involved which force the wire to not cut in a linear fashion. Imagine cutting a conic where the wire is forced out of sync with the top and bottom. A good example would be to draw a line from the beginning of a lower arc and then draw the other end of the line to the mid point of the top arc. Now imagine the line traveling around the arcs; it is not going to be accurate and that may be the reason why NX generated the error message. If you are selecting faces NX should create a good path if the geometry is able to be wire cut.

As for the nc file, my nc data looks like the Mastercam file so your post should be tweaked for your desired output. For my Fanuc IA posts I started with a generic control and customized it from there. I briefly checked the Siemens support site and I saw only Agie and Charmilles posts.

Can you download one of those to take a look at for a starting point on your post? If not then PM me and maybe I can give you a copy of my IA post. I have not worked on it much and aren't sure if all the codes will output correctly but you could start with that one. PM me if you want to give it a shot.

I have attached an image of a test block that I used to prove out a 4-axis wedm operation. The main reasons why select faces is the ease of selection. I can't imagine manually selecting chains to complete this! Of course selecting edges can be useful if you don't have a good solid or surface model to work with but I prefer to select faces.

[mazo]

Harold C,

I have read your post and I am nearly in the same situation like you. Also in our company we are using NX mainly for CNC milling but since we already have it I was selected by boss to "set it up" also for wire EDM. I have done the post by my self with a lot of efforts and a lot of test cuts. The was done when we were using NX3. In attachment I am sending you sample on my CNC code.

But when we move to NX6 real problems came
Since we do 4 axis work (with U and V in each line in the program) we also input offset in UG and here is where we CAN NOT USE NX6 since under
"Cutting>Stepover Parameters>Absolute Stock" we can not input values we want but UG does it by his own logic. I can not ask UG since my boss did not sign the maintenance contract (thanks for recession!!!) and in NX3 everything work just fine

Hope I helped and If anyone knows how to convince NX6 to use specified stepover parameters I would really appreciate if he would tell me how.