Need help cutting 2.5/3d parts.

[bdesh123]

HI everyone.
I want to list the steps needed to create a 2.5d part. I am done with designing the part (3d). after that I am lost. when i tranfer that to g code they are not the same. With this froums (ger21)s help I have my 1d plate parts done .need to practice some 3d cutting before I am done with the semister ( I will not be able to use autocad ne more) ( I like useing autocad, its easy and i did this model heli swashplate in 35 min). please help me list steps needed to cut a 2.5d part.
I faced the following questions

1 I am adding the files i made .dwg .. Am I drawing wrong? how should a 3d or 2.5d drawing look like.

2 what ever I have drawn useing mach2 .. when g code is generated , its not colse to what i have drawn.

3 If I am not wrong. z cord. on mach2 soft limit the depth of cut. if the line is anguler what i need to do .

I am adding the files and pics. please list the nessecery steps for 3d machining Will appriciate it

thanks in advance.

sami

[da21]

do you have the other parts in cad for the swashplate done , do they match etc , i prefer to import from autocad then into Rhino to make sure all parts are a good fit then check in visual mill for cutting etc and producing the gcode .seeing the paths in 3d for me helps ,then finaly use mach2 once i am satisfied , or to commiting to biting the bullet on the cnc .

no doubt more experienced people would miss out some steps , but i don't like to waste material , even so mistakes do happen , and some time you just need to go with
your thoughts , and suffer the will it work syndrome

[da21]

had a quick look and it's not generating the Z correctly to take into concideration of the control mounting lugs , i.e it's only generating the 2d as a flat part . hopfully someone with more experience with auto cad can shed some light , although i will take a longer look later today when i get back , i am also intreged with this problem , as i can see this happening to me at some time shortly , it may be a simple problem of adding an outline layer of the part as if it were a solid , instead of a doughnut with added lugs ,

Dave

[balsaman]

Mach2 only converts 2D drawings. You need a CAM program to put a tool path on that part.

Eric

[ger21]

You should be able to do *most* of what you want just using Mach2, but you have to know what your doing. When you import into Mach2, use the layer control to set the depth for each layer. A simpler way would possibly to have each layer actually be seperate .dxf files, which would possibly give you a liitle more control.

You really should just be drawing everything as a flat 2d drawing, but it can get confusing doing it that way. The way you have it, you have duplicate lines at the top and bottom. Mach2 only needs 1 line, not both.

You're going to have a problem cutting the angled part, as that is really a 3D part, not 2.5D. You can, however, do it in 2D or 2.5d. What you'd need to do, is offset the circles for the angled part by whatever amount you want the tool to stepover, and setting the depth different for each one to create the angle. Ideally, you'd use a ballnose tool to make this smoother. You'd probably need to rough it out, first. This can be very tedious, but it can be done. But you'll end up with a lot of lines in your drawing. I use a lisp program to automatically offset and step down my lines for cutting angled surfaces, but for Mach2 you'd still have to put each line on a different layer, and set the depth for each layer.


Like Eric says, the best way would be to use a CAM program. If that's not an option, here's what I'd recommend. try breaking the part down into simple steps. I'd probably first cut out the hole in the center, and then create the lip. Then rough out the material for the angle, and cut the angle. Then, I'd probably cut out the inside face of the 3 posts, and lastly, cut out the part around the entire perimeter.

This may be a little bit over your head, but start with small sections, and work your way up to the entire part. If you can use it, my AutoCAD 2 G-code macro might make it a lot easier for you. You can get it here: http://www.cnczone.com/forums/showth...5673#post75673

[bdesh123]

Hi everyone

thanks very much . I am looking for a CAM. something like Virtual MIll. and also going over the idea of cutting the parts seperately. its sure over my head. not ez atall. but I am learning .

thanks again
sami