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Haas ST20 Lathe VPS problems

Vinnie_Lathist

Plastic
Joined
Aug 12, 2021
Hi all. New to community but not new to machining. I have run (maintain, program & operate) Mazak lathes for ~15 years. I have been graciously given a Haas lathe from the powers that be. I have been messing around with it for around 4 months and keep having the same issue with the VPS. When using VPS putting a OD GROOVE, with a radius or chamfer, the VPS system does not complete the feature correctly. I end up with dual, square corners. I am using a .125" wide groove/turn tool. Any thoughts or tip would be greatly appreciated. This is not the only issue I have with the VPS system. Below is the output code for the OD GROOVE cycle, that the controller is generating;

(OD Groove)
(SAFETY LINE BELOW)
G00 G54 G18 G40 G80 G97 G99
(TOOL = 5 / OFFSET = 5)
(WORK OFFSET = 54)
(MAXIMUM SPINDLE RPM = 1500)
(CONSTANT SURFACE SPEED = 2000)
(GROOVE FINISH DIAMETER: 0.53)
(GROOVE WIDTH = 0.135)
(INSERT WIDTH = 0.125)
(SETTING 22 CHIP BREAK RETRACT = 0.01)
T505
G54
G50 S1500
G97 S600 M04
G00 Z0.1
G00 X0.987
M08
G96 S2000
G00 Z-2.67
G01 X0.987 F0.004
G75 I0.05 K0.1125 X0.545 Z-2.67 F0.004
G00 X0.987
G00 Z-2.537
G01 X0.802 Z-2.542 F0.004
G01 X0.787
G01 Z-2.665 ,R0.0
G01 X0.53
G01 Z-2.6694
G01 U0.015
G00 X0.987
G01 Z-2.803
G01 X0.802 Z-2.798
G01 X0.787
G01 Z-2.675 ,R0.0
G01 X0.53
G01 Z-2.6694
G01 U0.015
G00 X0.987
G00 Z0.1
G97 S600
M09
G00 X1. (SAFE TC POSITION)
G00 Z2.66 (SAFE TC POSITION)
M05
( END OD GROOVE CYCLE )
M01

I am going to the Haas training center in 2 weeks and will ask the same questions. Until then I'm going to try to only use the Haas lathe for show and tell. My 20+ old Mazak QT250 outperforms in almost every aspect and doesn't fight back so damn much.
 
According to your code you are putting a .005 chamfer on the corners.
I guarantee the radius on the corners of your .125 groove insert are bigger than that, so you're cutting air.

You're going to need to use TNR comp in your program or lie to the VPS to account for the radius on the insert.
 
Booze, I have been deleting the useless code for the double groove and adding C.118, where the controller places it as R0.0. I get the workaround but would like to know why the VPS faults in the translation. It does a similar error when programming a profile cycle. Moves G40 comp cancel into the wrong location, causing the first pass to be full depth and backwards. Kind of like a bar face operation on a Mazak. Frustrating having a new machine, that does not live up to the preached performance and ease of use IMO.
 
According to your code you are putting a .005 chamfer on the corners.
I guarantee the radius on the corners of your .125 groove insert are bigger than that, so you're cutting air.

You're going to need to use TNR comp in your program or lie to the VPS to account for the radius on the insert.


Adding to this, selecting the appropriate tip direction will also be important to creating the feature correctly
 
I don’t think tool tip number affects the code generated.
Sorry, no experience with any lathe conversational programming.
I have always just finger banged 2 axis lathe programs.
 
What is the radius on the insert itself? your program is showing you are trying to cut a .005 chamdfer as booze stated.
Under "edge break" in the VPS should be letter "R", guessing you know this but if you leave it as "C" (chamnfer) it obviously doesnt cut a corner rad, i use this all the time never had an issue but occasionally you do need to cheat it.
What is radius/chamfer are you trying to program in at the bottom of the groove?
 
The tool has a .008" radius. I found the problem to be related to the start position of the profile, in the VPS shape creator. I am currently at a Haas factory outlet training session and hit him with all the issues I have experienced up to this point. A lot of the problems revolve around my limited knowledge of G code.
 








 
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