Cut Path Not Following Gcode

More
15 Oct 2019 20:23 #147945 by MakingStuff
I have finally had some time to get the plasma cutter hooked up to my new setup using plasmaC and was able to make my first cut. Thanks to all that helped me get it going.

I immediately noticed that there was a problem after my first cut and I'm not sure what is going on here. I have attached an image that shows what is happening. If you look at the image you can see the white line that shows the gcode drawn out and the red line that is the path that the torch took. If you look inside the wrench on the right you can see the the mouth of the wrench was not cut square like the white line shows. The red line shows that there was a shortcut taken and the mouth of the wrench is rounded. This is clearly a software issue because LinuxCNC is showing the correct gcode drawing but the cut path is not the same. Is this a setting that I need to fix, or is there something else going on here?
Attachments:

Please Log in or Create an account to join the conversation.

More
15 Oct 2019 21:13 #147948 by tommylight
That is due to low acceleration/fast feed rate and can be eliminated by using G64 P0.1 if using mm.
Just put that at the top of gcode file.

Please Log in or Create an account to join the conversation.

More
15 Oct 2019 22:00 #147951 by MakingStuff

That is due to low acceleration/fast feed rate and can be eliminated by using G64 P0.1 if using mm.
Just put that at the top of gcode file.


I'm not using mm, I'm using imperial measurements.

Please Log in or Create an account to join the conversation.

More
15 Oct 2019 23:37 #147954 by tommylight

MakingStuff wrote:

That is due to low acceleration/fast feed rate and can be eliminated by using G64 P0.1 if using mm.
Just put that at the top of gcode file.


I'm not using mm, I'm using imperial measurements.

In that case
G64 P0.005 should be enough for plasma. That is basically the tolerance that the machine should follow, so nothing would go farther than that set tolerance from the actual tool path.
The following user(s) said Thank You: MakingStuff

Please Log in or Create an account to join the conversation.

More
15 Oct 2019 23:40 #147955 by OT-CNC
Replied by OT-CNC on topic Cut Path Not Following Gcode
It's part of path blending and you can set it to your liking.

More info here:

linuxcnc.org/docs/html/gcode/g-code.html#gcode:g64
The following user(s) said Thank You: tommylight, MakingStuff

Please Log in or Create an account to join the conversation.

More
16 Oct 2019 00:28 #147960 by MakingStuff
G64 P0.005 fixed the problem.

I have one more question. Why do I need this on my new setup, but it wasn't required on my old LinuxCNC 2.7 machine? Is this something new for LinxCNC 2.9?

Please Log in or Create an account to join the conversation.

More
16 Oct 2019 02:56 #147963 by Dinuka_Shehan
Can we use G61 or G64 in lathe mode?

Please Log in or Create an account to join the conversation.

More
16 Oct 2019 10:24 #147983 by tommylight

MakingStuff wrote: G64 P0.005 fixed the problem.

I have one more question. Why do I need this on my new setup, but it wasn't required on my old LinuxCNC 2.7 machine? Is this something new for LinxCNC 2.9?

That was changed during 2.7 when the new trajectory planer was implemented. It is in later versions of 2.7, 2.8 and 2.9.
The following user(s) said Thank You: phillc54

Please Log in or Create an account to join the conversation.

More
16 Oct 2019 11:31 #147990 by MakingStuff

That was changed during 2.7 when the new trajectory planer was implemented. It is in later versions of 2.7, 2.8 and 2.9.


Ok. Thanks for your help!

Bob
The following user(s) said Thank You: tommylight

Please Log in or Create an account to join the conversation.

More
18 Oct 2019 23:41 #148242 by phillc54
Oops, that is my fault.

There is a file called imperial_startup.ngc (or metric_startup.ngc) that sets G64 P0.04, it should have been G64 P 0.004. The metric version is correct at G64 P0.1

I will fix this.
The following user(s) said Thank You: thefabricator03

Please Log in or Create an account to join the conversation.

Moderators: phillc54
Time to create page: 0.099 seconds
Powered by Kunena Forum