What is 21/2 d?

[Larry Myers]

Hi ALl,

I am new here, new to G code, just bought a new VMC and Turbocad 12 Pro with cadcam plugin. Can someone tell me what 2.5 d is comparired to 3d? Thanks

Larry

[HuFlungDung]

Its a special cnc that scales everything in the Z axis to 1/2 of full size

Not really

Theoretically, a 2.5d cam is incapable of generating a ramping move that could have unique endpoints in all 3 axis. It could produce XY moves, followed by Z moves, all movements being produced by motors on the machine. If you imagine drilling holes with a manually operated quill, on a cnc that only positioned the table in X and Y, that would be 2d. Add a motor to the Z axis to pull the quill for you, you've got a .5d capability.

This definition may be too limited now, because modern cnc's are much more capable. 3 axis interpolation is easy to come by on the machine controller. So perhaps a more modern version of 2.5d would be cam software that can read only wireframe geometry information versus software that can create toolpaths from electronically modelled 3d surfaces.

[Larry Myers]

Hi Huflungdung,

Thank you for your response. One reason I ask is because I am at the beginning of a steep learning curve. Here’s my situation:

Just bought a new Sharp 2412 w/Fanuc Oi controller. I am just now learning G Code. I also just bought TurboCad12 Pro with the Cad cam plug-in.
Although I have used Turbocad 6 pro and 8, I am just beginning to learn 12. I am very comfortable with 6.

I have BobCad20 as well however from what I have seen on the tutorial, I doubt that I’ll like it. I do not know Bobcad 20 at all.

I am trying to figure out which I want to learn. I was a little apprehensive about this 2.5D issue. I really do not want to invest the time in learning Turbocad if it’s going to limit my capabilities down the road.
Any thoughts would be very appreciated!

Thanks again!!!!
Larry

[HuFlungDung]

What kind of part machining do you anticipate doing?

If the parts are drilling and tapping, or machining basic profiles, and simple pockets, a 2.5d cam software can get you quite some distance. However, there may be some wasted effort in learning that if you have the odd 3d surface thrown into the mix.

Bobcad 20 has nothing like an nc process manager to facilitate breaking your part program down into manageable chunks, when editing the program. The need for this will become apparent after you get more into machining.

I'd recommend that you look at a few more demo softwares, if for no other reason than to get a taste for the 'way its done' in pricier systems. I use OneCNC myself, they now have a demo that you can get. The cheaper versions of OneCNC are 2.5d as well, but you'll still get the idea of what an nc manager does. A lot of work that is done with a program like OneCNC in many job shops will rely heavily on the 2.5d (stock toolpaths) anyway, so if you learn the beginner versions, then advance later to the 3d stuff, its not like time wasted in learning, because the 3d (Surface Machining Technology) toolpaths are practically automatic anyway. That's how I got going in OneCNC as a matter of fact, producing 3d molds that Bobcad 18 couldn't touch, and doing it with a few mouse clicks. Mind you that was my first exposure to a more powerful (and modern) cam system, so it blew me away. And that was 3 versions ago.

[bborb]

Hi Larry,
You own some very powerful software and its good you're familiar with TurboCad already. Your CAM plug-in has a type of operations manager in that you can View & Edit by Tool, Operation or Part; reorder by Tool, Operation or Part.
I've used Turbocad Professional and BobCad together to generate toolpaths in G-code extensively in 2-1/2d or 3d. I think you'll find the plug-in in TurbCad most useful, utilizing BobCad more when you get into 3d work. I use the DXF import feature most in BobCad for 3d work, but unless you're going to be making artwork exclusively, learn the 2-1/2d process first and make some money while building a strong understanding of CAM and G-code.

[danil]

Hello guys,
This question is to bborb; what versions are you using of Bobcad and TurboCad. I too am just starting out on g-code and cam but have been drawing for several years and can draw most things in either inventor or autocad. I need to generate g-code for a haas gr408. I will have basic shapes to route out and some logo works that I'll be scanning from and generating toolpath. Seems like both have features to address these needs.
Thanks, Danil