Mastercam and Nurbs Interpolation

[PAnderson]

Hello All,

A question was raised on another forum on whether there are controls that can cut using splines. I know there are but my question is whether Mastercam can output Nurbs. I experimented with it briefly on a Fanuc 16i back in the 90's using Unigraphics. We did not pursue it because of various reasons, work load and perceived reliability being two of them. Has anyone here done it? Again, can Mastercam output and can someone get a reliable post from someone that really understands what's involved. I would like to hear anyone's stories on this matter. It came up again when we had Fanuc here for a webinar and they brought it up again. But nothing on it's usefulness except, yeah, we can do it. Does anybody do it?

 

Thanks,

Paul

[Orvie]

I hear that ICAM has a post engine that does this well.

[Guest]

The reality is NURBS Interpolation is old and outdated technology. It's heyday was in the mid-late 90's. HPCC is even old and outdated. That being said, should you choose to pursue it, you have a few options as far as I know; 1) like was stated above, ICAM, 2) MetaCut Finish/Pro from Northwood Designs (http://www.nwdesigns.com/Products/MCFinishNutshell.htm) and a couple of CAM Vendors.

 

What has replaced NURBS and HPCC is AICC-II, Nano-Smoothing, and Smooth Interpolation. When NURBS was developed, Data Servers were not commonplace, Block Processing Time (BPT) was not what it is today, and machine memory was still at a premium. Today that's all changed. Machines (at least the ones we sell) routinely ship with 8MB of NC Memory and 1GB Dataservers so program length is almost irrelevant. BPT is faster now and you have the capabilioty for 1,000 Block Look-Ahead.

 

JM2CFWIW, YMMV

[Mick]

I remember when the Unigraphics guy was doing the hard sell back in the nineties. "We support Nurbs output, so we're futureproofed. It is the future".

 

LOL, yeah, whatever

[Gracjan aka Pullo]

One thing which pretty much summarizes this is an example of a  NURBS  polynomial in the Heidenhain 426/430 manual .  I actually once entered it into the control and when I run it the control died on me.....There is no mention of NURBS in the fifth generation Heidenhain.  I remember once  talking to the Northwood bros at a dealer meet in Barcelona (early 2000s ? )  and they said that basically arcs and lines overtook the whole thing.  

 

 One thing always kept me wandering , if NURBS  polynomials come, how will I find a certain spot mid program on the control  

 

Gracjan