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lathe C axis code sample? Centroid < answered >

Posted: Wed Jan 03, 2018 10:11 pm
by frijoli
Are there any samples of C axis code fore Centroid controls. I am finding lots of examples that don't work, but none from actual Centroid machines. Centroid doesn't accept G17-G19 so I am confused on how Centroid intends it to be done.
There is nothing in the manual showing programming of wrapped tool paths nor face tool paths.

I did manage to write a post processor, in which I generated a program through Fusion 360 and generated a tool path that I believe will work.
Unfortunately it runs REALLY slow when using the c axis. I know why it's slow, but I don't know how to correct it.
So can anyone point me to some code?

Clay

Re: lathe C axis code sample? Centroid

Posted: Thu Jan 04, 2018 12:23 am
by cnckeith
clay, the reason its slow is the feedrate on the c axis program line is that the F command is in degrees per minute for a rotary axis.

so for example...

G1 Z2C3600 F2 that means the C axis is going to go 10 revolutions at 2 degrees per minute while the Z axis is interpolated to move to 2.0000 from the position it is at to 2.0000 in the time it takes for the C axis to rotate 10 times at 2 degrees per minute. (very slow)

Re: lathe C axis code sample? Centroid

Posted: Thu Jan 04, 2018 1:01 am
by Gary Campbell
Clay...
I have no idea how you get it into a Fusion postP, nor the syntax for math function in the Centroid controller, but what I have used in the past to get a realistic feedrate (matching XY) for a rotary axis is:

115 * ({desired surface feedrate} / {diameter})

Re: lathe C axis code sample? Centroid

Posted: Thu Jan 04, 2018 7:43 am
by frijoli
Gary Campbell wrote: Thu Jan 04, 2018 1:01 am Clay...
I have no idea how you get it into a Fusion postP, nor the syntax for math function in the Centroid controller, but what I have used in the past to get a realistic feedrate (matching XY) for a rotary axis is:

115 * ({desired surface feedrate} / {diameter})
Thanks Gary. What does the 115 represent? Also, how does that work when switching from rotary to straight lines? I assume you are programming this line by line as opposed to canned cycles?

Clay

Re: lathe C axis code sample? Centroid

Posted: Thu Jan 04, 2018 9:45 am
by Gary Campbell
Clay...
Round numbers for 114.59 or 360 / pi

Re: lathe C axis code sample? Centroid

Posted: Thu Jan 04, 2018 11:07 am
by cnc_smith
Clay,

I have attached a sample g-code program for C-axis for the Centroid lathe. This has the feed in degrees per minute. When X or Z are moving without a C-axis move on the same line of G code the feed rate (F) is in inches per minute. This program uses the M51 and M50 to turn C-axis on and off and the M23 and M25 to turn the live tooling on and off. ( If you are using different M codes for these functions you will have to change this program to those M codes to graph and run this program). This is the same part that is shown on the Centroid website. http://www.centroidcnc.com/cnc_c_axis_lathe.html
there are photos of the part and go down to the bottom and there is a video of the part being machined.

To use a third party post processor you'll need to set the CNC Controller type for the feed to Feed in degrees/minute.
C_AXIS_EXAMPLE_1.txt
I changed the file extension from .cnc to .txt to attach the file. Centroid will run this program with the .txt extension.
(16.27 KiB) Downloaded 153 times
caxis-tooling.jpg

Re: lathe C axis code sample? Centroid

Posted: Thu Jan 04, 2018 11:53 am
by frijoli
cnc_smith wrote: Thu Jan 04, 2018 11:07 am Clay,

I have attached a sample g-code program for C-axis for the Centroid lathe. This has the feed in degrees per minute. When X or Z are moving without a C-axis move on the same line of G code the feed rate (F) is in inches per minute. This program uses the M51 and M50 to turn C-axis on and off and the M23 and M25 to turn the live tooling on and off. ( If you are using different M codes for these functions you will have to change this program to those M codes to graph and run this program). This is the same part that is shown on the Centroid website. http://www.centroidcnc.com/cnc_c_axis_lathe.html
there are photos of the part and go down to the bottom and there is a video of the part being machined.

To use a third party post processor you'll need to set the CNC Controller type for the feed to Feed in degrees/minute.

C_AXIS_EXAMPLE_1.txt

caxis-tooling.jpg
Outstanding, Thank you!!

Clay :D