2D contour turn mill

[Anonymous]

Hi there.

Anyone knows any way to mill 2D contour around stock on a lathe by using only c and x axis, while x stays only positive?

[Anonymous]

Yeah, it's called "polar mode".

[Anonymous]

Thanks for help, but can you tell more about it please.

I,m using fanuc controls on a doosan lathe that is using Rs for radiuses,

my X0 is center of a part. Basically if i'm trying to program contour, fusion tries to go around profile from x positive to x negative while keeping my part sill in c, would be brilliant if i can keep cutter in x positive and just turn my part in c.

Sorry for my english and i'm fresh into cad cam software, but it would make my life way easier.

[Anonymous]

In sample I showed you G112 (g12.1) starts polar mode and G113 (G13.1) cancels it, There are two key functions of polar mode and polar mode only works in G17 plane..

1) It converts all Y axis Cartesian moves in G17 plane into movement of C axis in degrees, for every X axis coordinate there is corresponding translation of Y coordinate in form of angle position.

2) Any time tool is about to cross center line of spindle, C axis is rotated instead so that tool always works on positive side of X axis.

"I" and "K" variables are used in arcs as far more accurate then "R"  variable, you can set your post to use either one, in many cases you can switch that in user variable window before posting file.

M codes shown in my sample are adequate for machine I run, yours will very depending on machine tool brand and control type.

Basically, orient your tool as shown in my sample and program tool path, if your post processor is set correctly for machine you have, code should be valid to run.

If you want tool to start at certain point on milled feature, set your X axis in setup to point to that feature or actual location by using model edge or sketch to set X axis orientation.

When you post process the file, that point becomes C0 and initial C axis orientation only deviates from it to execute any lead in arc move and cutter compensation.

Confused yet?,........ practice makes perfect and there are books that teach all that, one likely came with your machine and I can't learn things for you and then tell you what to do, it's not core purpose of this forum, but I don't mind sharing what I offered so far.

[Anonymous]

Thanks a lot, was confused a bit. Basically did exactly what you said , and yes y axic did switched to c, but looking at the code posted by procesor my cutter still tries to go negative after reaching X0. Can it be be post processor issue?

[Anonymous]

Negative X coordinates in code will be positive when you run it in machine, C axis will rotate so tool works above center line, assuming your post is correctly configured.

There are negative X coordinates in my sample code too but that does not make tool go below center line, I have proven post for machine I work with. 

[Anonymous]

Ok thanks.

I’ll try it in a minute in a fresh air, and will see if it works

[Anonymous]

Runs fine in my machine, .... always did. 

[Anonymous]

Yes it did. Thank you... done it properly at the first point, but eas scared by the code, thank you for explanation.

[Anonymous · Accepted solution]

Now you give yourself pad on the back, mark this post solved so other beginners can find it and send me a beer.

[andreshadow]

Hi.

I'm not sure if I can write in closed post but i have question related to this issue.. I think.

My problem is that I want to make Fusion to use c-axis instead of y-axis. I made part just like you did and when milling around its ok. Post in c-axis but when I added flat that flat is milled with y-axis. I know I'm doing something wrong here because some times when I'm making flat like this it does post in c-axis. Please help.

I'm using post for Doosan mill turn fanuc 31i from website.

Is there option to tick for using c-axis or y-axis ?

[seth.madore]

Set it to Lynx (not Lynx with Y-axis)

 

M110
G0 G28 G53 B0. (SUB SPINDLE RETURN)
G28 U0.
G28 W0.
M90
G54
G98 G18 M35
G0 G28 H0.
T0101
M8
G97 S5000 M3 P12
G0 Z15.
X112.
C0.
G12.1
G1 C0. F1500.
Z5.
Z1. F333.33
Z-57.5
X110. F1000.
G2 X-55. C-47.631 I-55. J0.
C47.631 I27.5 J47.631
X110. C0. I27.5 J-47.631
G1 X112.
Z15. F1500.
G13.1
(2D CONTOUR3)
G0 C0.
G12.1
G1 X-102. C-21.795 Z15. F1500.
Z5.
Z1. F333.33
Z-33.5
X-100. F1000.
C21.795
X-102.
Z15. F1500.
G13.1
M5 P12
M9
G0 G28 U0.
G28 W0.
G0 G28 G53 B0. (SUB SPINDLE RETURN)
M35
G28 H0.

[andreshadow]

Thank you. Didn't realise there is option like this. Works perfectly.