Problem setting Feed rate w G-code

[mlind]

Hello,

I am having a problem with this section of Code and thought I would ask for help setting feedrate to 0.5 on this one line. I have tried many different things but no help. Any suggestions would be welcome. Thanks in advance.


N038 G00 X000.750 Y002.000
N039 G01 Z001.1
N040 G01 X002.000 Y000.750 F.5 (This is where I need feed rate set to 0.5)
N041 G01 X000.750 Y002.000
N042 G00 Z000.000

[annoying]

Originally Posted by mlind Hello, I am having a problem with this section of Code and thought I would ask for help setting feedrate to 0.5 on this one line. I have tried many different things but no help. Any suggestions would be welcome. Thanks in advance. N038 G00 X000.750 Y002.000 N039 G01 Z001.1 N040 G01 X002.000 Y000.750 F.5 (This is where I need feed rate set to 0.5) N041 G01 X000.750 Y002.000 N042 G00 Z000.000

What is the machine? Can you post more from the beginning?

[mlind]

Hello,

Thank you in advance. Here is the g-code file. The machine is a cnc router made by Thom Carr CNC.

Basically I am first cutting 4 pointlists then going back to the pointlists and cuting 4 45 degree slots. On the 4 slots I need to slow the feed rate down to a crawl. I use Kcam for the controller.


N001 [KCAM CONVERSION]
N002 [ORIGINAL FILE: BALLNOSESLOTCUTTERFIRST.DXF]
N003 %
N004 G90
N005 M03
N006 G00 Z000.000 ( point list begin )
N007 G00 X002.000 Y009.250
N008 G01 Z001.1
N009 G01 X002.000 Y009.250 Z000.000
N010 G00 Z000.000
N011 G00 X008.000 Y009.250
N012 G01 Z001.1
N013 G01 X008.000 Y009.250 Z000.000
N014 G00 Z000.000
N015 G00 X009.250 Y002.000
N016 G01 Z001.1
N017 G01 X009.250 Y002.000 Z000.000
N018 G00 Z000.000
N019 G00 X000.750 Y002.000
N020 G01 Z001.1 Pointlist end
N021 G01 X000.750 Y002.000 Z000.000
N022 G00 Z000.000
N023 G00 X002.000 Y009.250
N024 G01 Z001.1 0 Begin 4 angle cuts need slow speed here
N025 G01 X000.750 Y008.000
N026 G01 X002.000 Y009.250
N027 G00 Z000.000
N028 G00 X008.000 Y009.250
N029 G01 Z001.1
N030 G01 X009.250 Y008.000
N031 G01 X008.000 Y009.250
N032 G00 Z000.000
N033 G00 X009.250 Y002.000
N034 G01 Z0001.1
N035 G01 X008.000 Y000.750
N036 G01 X009.250 Y002.000
N037 G00 Z000.000
N038 G00 X000.750 Y002.000
N039 G01 Z001.1
N040 G01 X002.000 Y000.750
N041 G01 X000.750 Y002.000
N042 G00 Z000.000
N043 M05
N044 M30
end.

[lukewarm]

Try lowering your ramp start value below the lowest speed you wish to cut at and try again.

[mlind]

Originally Posted by lukewarm Try lowering your ramp start value below the lowest speed you wish to cut at and try again.

Good Idea,

I was going to do 2 programs one with a low feed rate to cut the angles then another program to complete the project but I would like to learn how to set feed rates in a g-code program. More of a wondering how to rather than a need too as I can get around it but it would be nice to be able to program feed rates into a g-code program when needed.

Thanks for the idea.

[judleroy]

I don't know the answer to your problem sorry. All the machines i've used would cut at F.5 or sometimes F0.5 depending on machine. Will the machine feed that slow? I'm really wondering why all the extra zeros in your code. Whynot X0.0 or even X0.0000.
Do you write the code on the machine? The X000.005 would have me seriously confused.Lol. Good luck with your problem.
Judleroy

[annoying]

Hey, that stuff gives me a headache. Waaaay too many 0s. Don't know anything about the Kcam you are using.
I'd expect it should hopefully handle .5 ipm, but cannot say. I did not see any other specified feedrate in there.

But, I'd have it more like this:


N001

............


N012G1Z1.1
N013G1X8Y9.25Z0
N014G0Z0
N015G0X9.25Y2
N016G1Z1.1
N017G1X9.25Y2.Z0
N018G0Z0

..........



Actually I seldom number the blocks unless I might need them for restart points or branching. However, your Kcam may not accept code like that.... it could well be quite different than what I've used

But setting feedrate should well be done in the line where you are starting that feedrate, in the form of F.5 or F0.5 and should remain until changed. It can also be placed in its own seperate line before the movement. This is in the case of metal working machinery that I have used

[lukewarm]

You misunderstand me I believe you are unable to set your feeds that low because your ramp values are above it. Therefore if you set your ramp values below it you will be able to set low feed rates and this issue will be solved. The ramp start values are part of your kcam config I believe.

Originally Posted by mlind Good Idea, I was going to do 2 programs one with a low feed rate to cut the angles then another program to complete the project but I would like to learn how to set feed rates in a g-code program. More of a wondering how to rather than a need too as I can get around it but it would be nice to be able to program feed rates into a g-code program when needed. Thanks for the idea.

[mlind]

Oh!! DUH

I see what you are saying now. That makes sense as I tried to set the feedrate both above and on the same line as the code which had no effect what soever..... (SMILE) I'll bet you are right about setting the ramp rate lower than the feedrate. Thank you so much.....

I can't wait to get home and try it..

Thanks one and all I'll give it a try later this week and see if that helps....

Originally Posted by lukewarm You misunderstand me I believe you are unable to set your feeds that low because your ramp values are above it. Therefore if you set your ramp values below it you will be able to set low feed rates and this issue will be solved. The ramp start values are part of your kcam config I believe.

[mlind]

Hello,

I didn't write the code but rather had the controller convert a dxf file to g-code. I can set the number of decimal places in the program and I guess I have grown used to this format. (SMILE) Although it isn't necessary. The machine will cut really slow it was cutting at .001 ipm although the only way to tell it was cutting was to watch the readout. Its kind of fun experimenting with stuff like this.

Thanks...

Originally Posted by judleroy I don't know the answer to your problem sorry. All the machines i've used would cut at F.5 or sometimes F0.5 depending on machine. Will the machine feed that slow? I'm really wondering why all the extra zeros in your code. Whynot X0.0 or even X0.0000. Do you write the code on the machine? The X000.005 would have me seriously confused.Lol. Good luck with your problem. Judleroy

[lukewarm]

Hope it works out for ya!

[mlind]

Thanks for the insight. Its neat to see the way other folks do their code.

I took out the F0 commands but I think setting the correct the ramp rate will solve the problem. The machine will cut verrrrrrrrrrrryyyyyyyyyy slow ( I discovered how slow the other day). :-) Kcam is a good controller for what I do. Thanks for the info on how to set the feedrate ...

Originally Posted by annoying Hey, that stuff gives me a headache. Waaaay too many 0s. Don't know anything about the Kcam you are using. I'd expect it should hopefully handle .5 ipm, but cannot say. I did not see any other specified feedrate in there. But, I'd have it more like this: N001 ............ N012G1Z1.1 N013G1X8Y9.25Z0 N014G0Z0 N015G0X9.25Y2 N016G1Z1.1 N017G1X9.25Y2.Z0 N018G0Z0 .......... Actually I seldom number the blocks unless I might need them for restart points or branching. However, your Kcam may not accept code like that.... it could well be quite different than what I've used But setting feedrate should well be done in the line where you are starting that feedrate, in the form of F.5 or F0.5 and should remain until changed. It can also be placed in its own seperate line before the movement. This is in the case of metal working machinery that I have used