12-Amethyst

Question

Trajectory Milling

Forum|Forum|9 years ago
October 13, 2016
4 replies
8623 views

Had some free time to work on this today. Source link

I created a curve by equation and used that to drive a trajectory milling sequence for some long slots I needed to mill.

here is the equation I used to create this curve.

/* ENTER TOOL STEP OVER

SO = 0.05

/* EMPIRICAL VALUE TO CORRECT SHAPE ERROR

SF = 0.0175

/* ENTER PROFILE ALLOWANCE (STOCK)

PA = 0.005

/* ENTER TOOL CUTTER DIAMETER

CD = .3937

/* ENTER SLOT WIDTH

SW = 0.811977

/* ENTER NUMBER OF REVOLUTIONS

N = 100

A = ( ( SO * SF ) / 3.141592654 ) / 2

B = ( ( SW - ( 2 * PA ) ) - CD ) / 2

x = ( A * ( t * N * 360 )) - ( B * sin ( t * N * 360 ) )

y = ( B * cos ( t * N * 360 ))

z = 0

I don't understand what the shape error value is about but it seems to work for this application. Just thought i should share this with everyone in case they wanted to use it or improve it

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General

S

SteveLucas

1-Visitor

Nick,

Nice looking tool path !

N

NickMihelich

Author

12-Amethyst

Thank you

I'm finding that the cl data and g-code is all points so now am looking into arc fitting but not sure if this is a wise move.

J

joshuataylor

1-Visitor

Interesting application.

If you are using creo3you can do something similar using volume-mill and the cl data isn't all pts. This would allow you to control tool selection and parameter adjustment normally. You can also do slots that aren't straight.

Josh

N

NickMihelich

Author

12-Amethyst

oooh i like the look of that cl data but volumill is extra $ correct?

J

joshuataylor

1-Visitor

Don't know, sorry.

Josh

D

dford

1-Visitor

I haven't been doing any programming for a couple years now, but was reading through the forum to see what's new. I used a similar technique as Nick and also didn't have an accurate solution to the step-over value - I just tweaked the STEP value to get what I needed. I didn't use it frequently enough to invest time resolving the step over issue.

Throchoidal milling curve: I used a CSYS to anchor the start of the curve orientation of the path - the default vector for the path is Y+. I could also juggle the X/Y calculations to control the vector and climb/conventional cutting condition as shown in the example.

/*-------------------------------------------------------------------
/*
/* RAD = radius of path (slot_radius - cutter_radius)
/* STEP = determines "step-over", **STILL GUESSING ON VALUE**
/* DIST = total travel distance
/* DEGS = CALCULATED, DEGREES: distance_required/step*2*360
/* ------- FORMAT -------
/* x = (STEP-RAD*cos(t*DEGS))-STEP
/* y = STEP*((t*DEGS*STEP*3.14159)/360) - RAD*sin(t*DEGS)
/* z = 0.
/*
/* -- OPTIONAL -- ADD THE FOLLOWING PARAMETERS TO THE ASSEMBLY --
/* NR: RAD (REAL NUMBER, 0.0)
/* NR: STEP (REAL NUMBER, 0.0)
/* NR: DIST (REAL NUMBER, 0.0)
/* NR: DEGS (REAL NUMBER, 0.0)
/*
/*
/*------------------------------------------------------------------
/* -- IN SAMPLE BELOW X/Y REVERSED FOR X+ ADVANCING CUTS
/* -- IN SAMPLE BELOW Y IS REVERSED FOR CLIMB: "-(STEP" & "+STEP"