G00 Rapid on CNC Mill - question

M

MarkyPete

Plastic

Joined

May 28, 2015

• Jun 5, 2019

• #1

Hi fellow members.

On a Matsuura MAM72-VS (Vertical machine with B axis tilt / C axis rotation) I'm running into a situation with simultaneous 5-axis rapid motion. That is, the axis are completing their commanded motions interdependently, and I get a "dog leg" effect.

I would like the Fanuc 16i-M control to manage the rapid moves to arrive at destination simultaneously. Unfortunately, I don't know the parameter setting, if there's even one.

Thank you for your help.

Mark S.

 

L

Larry Dickman

Titanium

Joined

Jan 30, 2014

Location

Temecula, Ca

• Jun 5, 2019

• #2

What are you programming with? Most CAM that I'm familiar with have a "Rapid Feed" option, so it will "FEED" using G1, but at a faster rate (user defined). This eliminates the dreaded dogleg.

 

dandrummerman21

Stainless

Joined

Feb 5, 2008

Location

MI, USA

• Jun 5, 2019

• #3

From the parameter manual, it appears it may be 1401 bit 1 LRP:

LRP Positioning (G00)
0: Positioning is performed with non–linear type positioning so that the
tool moves along each axis independently at rapid traverse.
1: Positioning is performed with linear interpolation so that the tool
moves in a straight line.

 

npolanosky

Cast Iron

Joined

Apr 9, 2016

Location

USA, FL

• Jun 5, 2019

• #4

https://jamet.com/Fanuc_Web_Manuals/CNCs_Current/63530EN.pdf

Parameter 1401 Bit 1(second from the right), labeled LRP. Set it to 1 for linear rapids, set to 0 for dogleg.

You may want to call Matsuura to make sure that won't break anything and there's nothing else you need to change, considering it's a 5 axis. I saw a handful of other parameters that change behavior based on the state of that one.

 

V

Vancbiker

Diamond

Joined

Jan 5, 2014

Location

Vancouver, WA. USA

• Jun 5, 2019

• #5

One should keep in mind that the linear rapid G00 function is not the same as linear interpolation G01 function. The linear rapid is "approximately" linear, not as tightly controlled as G01 linear interpolation. On smaller machines the error is typically very small as to be unnoticeable. On large machines (1.5 meter + travels), I have seen deviations of at least an inch when comparing rapids at 25% versus 100%.

 

T

Tichy

Aluminum

Joined

Jan 1, 2019

• Jun 6, 2019

• #6

Or you could just do G1 at maximum feed rate.

 

Rick Finsta

Stainless

Joined

Sep 27, 2017

• Jun 6, 2019

• #7

I think this explains the behavior I am seeing on a program on our MX-520! It goes into G00 to transition along a shortest path and does very slow, jerky moves?

 

npolanosky

Cast Iron

Joined

Apr 9, 2016

Location

USA, FL

• Jun 6, 2019

• #8

Tichy said:

Or you could just do G1 at maximum feed rate.

Click to expand...

That's a good point. Have you tried setting your CAM post to output high feed moves instead?

 

B

beretta136

Plastic

Joined

Nov 20, 2023

• Feb 10, 2024

• #9

MarkyPete said:

Hi fellow members.

On a Matsuura MAM72-VS (Vertical machine with B axis tilt / C axis rotation) I'm running into a situation with simultaneous 5-axis rapid motion. That is, the axis are completing their commanded motions interdependently, and I get a "dog leg" effect.

I would like the Fanuc 16i-M control to manage the rapid moves to arrive at destination simultaneously. Unfortunately, I don't know the parameter setting, if there's even one.

Thank you for your help.

Mark S.

Click to expand...

Mark,

As you did few years ago I am looking for the Matsuura MAM-72-3VS manual. I was wondering if have it ?