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Author Topic: Circles with shared center not aligning.  (Read 3163 times)

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Circles with shared center not aligning.
« on: May 03, 2011, 11:49:46 PM »
I'm having issue with three circles that share the same center not aligning.  I'm trying to cut a .20" hole with a 1/8" mill, then cut a .36" diameter countersink with a 1/4" mill and then bevel the top edge of the larger circle.  The 2nd circle is centering roughly -.015" off center on the Y axis.  The 3rd circle lines up fine with the 2nd.  The circles are cutting true, not ovalled.

I thought I may be losing steps but when I jog the X and Y axis and restart the program from random points, the 1/8" mill returns to the previously cut hole and runs through the cut without even touching the previously cut edges.

I tried changing mills without moving the X or Y axis and it still happens repeatedly.

It's probably obvious, but I'm pretty new to CNC.  I'm using LazyCam and Mach 3 with a homemade CNC purchased off eBay.

Please advise...


Here's the code:

N5 (File Name = hole on Tuesday, May 03, 2011)
N10 (Default Mill Post)
N15  G91.1
N20 M5 M9
N25 M6 T15(TOOL Change 1/8" cuttng aluminum)
N30 G43 H15
N35 G0  Z0.3000
N40 M3 S6000
N45  X0.2175  Y0.1800
N50  Z0.0803
N55 G1  Z0.0700  F2.00
N60 G2  I-0.0375  J0.0000  F12.00
N65 G0  Z0.0803
N70 G1  Z0.0600  F2.00
N75 G2  I-0.0375  J0.0000  F12.00
N80 G0  Z0.0803
N85 G1  Z0.0500  F2.00
N90 G2  I-0.0375  J0.0000  F12.00
N95 G0  Z0.0803
N100 G1  Z0.0400  F2.00
N105 G2  I-0.0375  J0.0000  F12.00
N110 G0  Z0.0803
N115 G1  Z0.0300  F2.00
N120 G2  I-0.0375  J0.0000  F12.00
N125 G0  Z0.0803
N130 G1  Z0.0200  F2.00
N135 G2  I-0.0375  J0.0000  F12.00
N140 G0  Z0.0803
N145 G1  Z0.0100  F2.00
N150 G2  I-0.0375  J0.0000  F12.00
N155 G0  Z0.0803
N160 G1  Z0.0000  F2.00
N165 G2  I-0.0375  J0.0000  F12.00
N170 G0  Z0.0803
N175 G1  Z-0.0100  F2.00
N180 G2  I-0.0375  J0.0000  F12.00
N185 G0  Z0.0803
N190 G1  Z-0.0200  F2.00
N195 G2  I-0.0375  J0.0000  F12.00
N200 G0  Z0.0803
N205 G1  Z-0.0300  F2.00
N210 G2  I-0.0375  J0.0000  F12.00
N215 G0  Z0.0803
N220 G1  Z-0.0400  F2.00
N225 G2  I-0.0375  J0.0000  F12.00
N230 G0  Z0.0803
N235 G1  Z-0.0500  F2.00
N240 G2  I-0.0375  J0.0000  F12.00
N245 G0  Z0.0803
N250 G1  Z-0.0600  F2.00
N255 G2  I-0.0375  J0.0000  F12.00
N260 G0  Z0.0803
N265 G1  Z-0.0700  F2.00
N270 G2  I-0.0375  J0.0000  F12.00
N275 G0  Z0.0803
N280 G1  Z-0.0700  F2.00
N285 G2  I-0.0375  J0.0000  F12.00
N290 M5 M9
N295 M6 T5(TOOL Change 1/4" roughing)
N300 G43 H5
N305 G0  Z0.3000
N310 M3
N315  X0.2350
N320  Z0.0803
N325 G1  Z0.0700  F2.00
N330 G2  I-0.0550  J0.0000  F20.00
N335 G0  Z0.0803
N340 G1  Z0.0600  F2.00
N345 G2  I-0.0550  J0.0000  F20.00
N350 G0  Z0.0803
N355 G1  Z0.0500  F2.00
N360 G2  I-0.0550  J0.0000  F20.00
N365 G0  Z0.0803
N370 G1  Z0.0400  F2.00
N375 G2  I-0.0550  J0.0000  F20.00
N380 G0  Z0.0803
N385 G1  Z0.0300  F2.00
N390 G2  I-0.0550  J0.0000  F20.00
N395 G0  Z0.0803
N400 G1  Z0.0200  F2.00
N405 G2  I-0.0550  J0.0000  F20.00
N410 G0  Z0.0803
N415 G1  Z0.0100  F2.00
N420 G2  I-0.0550  J0.0000  F20.00
N425 G0  Z0.0803
N430 G1  Z0.0000  F2.00
N435 G2  I-0.0550  J0.0000  F20.00
N440 G0  Z0.0803
N445 G1  Z-0.0100  F2.00
N450 G2  I-0.0550  J0.0000  F20.00
N455 G0  Z0.0803
N460 G1  Z-0.0100  F2.00
N465 G2  I-0.0550  J0.0000  F20.00
N470 M5 M9
N475 M6 T19(TOOL Change .25" 45 deg)
N480 G43 H19
N485 G0  Z0.3000
N490 M3
N495  X0.3600
N500  Z0.0803
N505 G1  Z0.0700  F2.00
N510 G2  I-0.1800  J0.0000  F20.00
N515 G0  Z0.0803
N520 G1  Z0.0600  F2.00
N525 G2  I-0.1800  J0.0000  F20.00
N530 G0  Z0.0803
N535 G1  Z0.0500  F2.00
N540 G2  I-0.1800  J0.0000  F20.00
N545 G0  Z0.0803
N550 G1  Z0.0400  F2.00
N555 G2  I-0.1800  J0.0000  F20.00
N560 G0  Z0.0803
N565 G1  Z0.0300  F2.00
N570 G2  I-0.1800  J0.0000  F20.00
N575 G0  Z0.0803
N580 G1  Z0.0200  F2.00
N585 G2  I-0.1800  J0.0000  F20.00
N590 G0  Z0.0803
N595 G1  Z0.0100  F2.00
N600 G2  I-0.1800  J0.0000  F20.00
N605 G0  Z0.0803
N610 G1  Z0.0000  F2.00
N615 G2  I-0.1800  J0.0000  F20.00
N620 G0  Z0.0803
N625 G1  Z-0.0100  F2.00
N630 G2  I-0.1800  J0.0000  F20.00
N635 G0  Z0.0803
N640 G1  Z-0.0100  F2.00
N645 G2  I-0.1800  J0.0000  F20.00
N650 G0  Z0.3000
N655 M5
N660 M30



Offline RICH

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Re: Circles with shared center not aligning.
« Reply #1 on: May 04, 2011, 06:44:28 AM »
The circles all have the same center line so seems as it is a machine problem....check your steps per unit.
RICH
Re: Circles with shared center not aligning.
« Reply #2 on: May 04, 2011, 10:49:24 AM »
That was my first thought.  If I were loosing steps, wouldn't the 3rd circle be equally off from the 2nd?  Also, between tool changes, I am not moving the X or Y axis.  I only raise the Z to change tools.

Offline RICH

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Re: Circles with shared center not aligning.
« Reply #3 on: May 04, 2011, 07:09:08 PM »
I didn't see anything wrong with the code when I quickly backplotted it to CAD.
If the first circle comes out right, then maybe it's in the rapid move to the 2nd circle that things are getting off, so, you maybe slow the axis velocity down some and see how it goes.
RICH

Offline RICH

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Re: Circles with shared center not aligning.
« Reply #4 on: May 07, 2011, 06:05:34 PM »
Maybe i am missing something but looks ok when i backplot to CAD ( all circles have the same center point relative to origin ) and LC output code is the same for the first two steps when i create offsets using 1/8 and 1/4 dia end mills.  ???
RICH