Solid model to CNC code quession

[mikenelson]

We have both Pro/Engineer and SolidWorks here and use AlphaCAM from Licom to program our Hass 5 axis mill. We recently lost our programming expert and I am trying to get an understanding of what this system should be capable of. I am told that they (the workshop) can only work from 2D dxf file input and that seems to me to be a very limited and error prone way of inputting the CAD models. I expected that I would be able to send them a 3D model in an appropriate format (iges,step,parasolid,etc) and the ALphaCAM software would enable the CAM programmer to apply the appropriate cutters to the shapes to generate the machining code. Our workshop tells me that they can only work from 3D data when machining conplex shapes using a ball nosed cutter but I feel sure that this is really that they just don't know how to use the model. I am not a CNC programmer but am an experienced user of CAD software. I need to gain enough knowledge to work with our workshop to make the machining of designs like the one in the attached picture achievable from a 3D model and thus avoiding the errors that are happening when working from 2D data.

[GOMEZ107]

Mikenelson,

You don't need 3d data to work with the sample images you show in the thread, those are simple parts that a 2d drawing will be enough. They may require multiple setups, but in the overall, they are very simple parts to do. Remember , in the shop , a machinist only needs to know the tickness, the length and width of a part(plus the position of other features, as holes, pockets and the likes), and a good 2d drawing with a couple of views and cut off willdo.

gomez107

[cadcam]

Mike you are right they should be able to take the 3d model and make code from it. I don,t know that pertuclure software, but I do 5axis and this is a must in this arena.

And as per having the model to a print I am much fater to the muchine this way by far.

[HuFlungDung]

Hi Mike,

I'm pretty new to the field of true 3d software myself (I use OnecncXP for 3 axis milling) but I am coming to appreciate quite strongly the benefits of using solid models, even for 2d type jobs, expecially since my software is able to create whatever type of path is needed, whether it be 2d or whatever. This eliminates having to redraw parts (error prone) and also eliminates the dangers of rapid gouging. The proofing tools are exceptional as well, so you can simulate the nc code very precisely to be assured that whatever nc code you have created is proper.

Sure, you can "fool around" with 2d CAD and create toolpaths, but as you suggest, that is not the modern way to work. Perhaps your machinists are "afraid" to use the high class software that your shop is licenced for? I have no idea how machinist friendly those programs are to work with. Could this be the source of the resistance to "make the switch" to full 3d?

As a small shop owner, head programmer and chief of the cnc department (I am the cnc department ), I can vouch for the user friendliness of the software I use, and I feel it represents an intuitive CADCAM solution that your machinists would be able to use to comfortably handle a lot of your programming (up to 3 axis anyways) with a minimal learning curve.

[mikenelson]

Hi Thanks for the reply. I know that this part can be done using just the 2D data an indeed give me a Bridgeport and a cutter and I could make it the old way from a drawing. It is really just an example. What I am trying to acertain is that it is perfectly feasable that top-end commercial CAM software can take in the 3D model of a part like this and allow the machine code to be generated.

[Buried]

I would have to agree with cadcam and HuFlung. Yes the parts in the pics could be done with some 2d drawings, but i believe you could accomplish the same thing faster (and I would think more efficiently(sp?))with the 3d Model....or I could anyway.



As for AlphaCAM, I've never heard of it, so I'm not quite sure what it can accomplish.Only able to import 2d sounds pretty strange....It can only import 2d, but you can make 3d surface toolpaths with it?



Does anyone else smell that?......

[HuFlungDung]

Mike, I'd like to add that perhaps some of your other people think that we only need to use full blown 3d CADCAM when the complexities of 3d geometry dictate it, but what is often overlooked, is that the processes in 2d are often much more complicated to program for. By this I mean that quite a bit more mental programming effort is required "per line of nc code output" for a part that is made of (many) 2d processes.

This is where I found Onecnc's NC manager to be of immense benefit, because it allows me to document what I used to carry in my head out to the machine. This much more effectively captures what procedures were used, in the event that I come back to the same part in a few months, and want to modify the methods of machining it.

[CAMmando]

Most likely when importing solids into your "Alpha CAM" (which Im not familiar with) the resulting geometry is surfaces (maybe solids). For 2 1/2 axis milling, most toolpathing is accpmplished easiest by using drive curves not surfaces or solids. Extracting drive curves from solids or surfaces can at times be tedious until you are familaiar how to flavor the iges (or step or whatever) output and input of the systems involved. So for a part like you have shown, I would ask for the following using MasterCAM:

1) Step, ACIS, or Parasolids file.

OR

2) IGES With surfaces and wireframe either in separate or a single file.


DXF would be the last (worst choice).

This assumes your models are accurate and modeled at "Nominal".

It is possible that AlphaCam doesnt deal well with extracting drive curves from surfaces or solids. But I still cant imagine why someone would prefer DXF over Iges since DXF is strictly a 2D format. Unless they just dont trust your Models.

[Mortek]

Sounds to me like you may not be getting straight information on the Alphcam from the shop or maybe they don't know it's limitations or capabilities. I would get the manual to the Alphacam and see for myself what kind of file formats it can handle and whether it is capable of doing both 2d and 3d work as you would like.

[hardmill]

http://www.alphacam.com/licom/Home.cfm?Language=US

[hardmill]

http://www.alphacam.com/licom/Home.cfm?Language=US

PEACE