router feed pausing at corners

[Heritage820]

Hi, I am using a 3/8" compression bit to do cut outer profiles in plywood. The router stops at each corner for about 5 seconds then continues on with the cut until the next turn, and does it again. Its creating a fire hazard by burning the sawdust and turning it into embers! Is this a post processor issue or do I have a setting wrong?

Thanks!
JP

[martin54]

It is most likely a setting in your machine control software rather than the post-processor you are using. I would speak to the machine manufacturer about this or if they have a forum ask on there.
Maybe someone with the same machine or same control software can give you a better answer

[SteveNelson46]

Are you using a post processor that uses arcs?

[Heritage820]

Not using arcs in the post. I was looking at the GCode and wondering why the y axis and then x axis are missing on certain lines, wondering if this is a clue-

Here is an excerpt-

G1 X33.014 Y382.617
G1 X33.192 Y382.600
G1 X33.368 Y382.591
G1 X33.542 Y382.587
G1 X338.342
G1 X338.516 Y382.591
G1 X338.692 Y382.600
G1 X338.870 Y382.617
G1 X339.050 Y382.640
G1 X339.231 Y382.671
G1 X339.413 Y382.710
G1 X339.595 Y382.755
G1 X339.778 Y382.809
G1 X339.959 Y382.871
G1 X340.140 Y382.940
G1 X340.319 Y383.017
G1 X340.496 Y383.103
G1 X340.671 Y383.196
G1 X340.843 Y383.297
G1 X341.011 Y383.405
G1 X341.174 Y383.521
G1 X341.334 Y383.645
G1 X341.488 Y383.775
G1 X341.637 Y383.912
G1 X341.780 Y384.055
G1 X341.917 Y384.204
G1 X342.047 Y384.358
G1 X342.170 Y384.517
G1 X342.286 Y384.681
G1 X342.395 Y384.849
G1 X342.496 Y385.021
G1 X342.589 Y385.196
G1 X342.675 Y385.373
G1 X342.752 Y385.552
G1 X342.821 Y385.733
G1 X342.883 Y385.914
G1 X342.936 Y386.097
G1 X342.982 Y386.279
G1 X343.021 Y386.461
G1 X343.051 Y386.642
G1 X343.075 Y386.822
G1 X343.091 Y387.000
G1 X343.101 Y387.176
G1 X343.104 Y387.350
G1 Y692.150
G1 X343.101 Y692.324
G1 X343.091 Y692.500
G1 X343.075 Y692.678
G1 X343.051 Y692.858
G1 X343.021 Y693.039
G1 X342.982 Y693.221

[Mark]

Hello JP.

There are no G4 dwell commands within the code, so there is nothing in the code that is telling the machine to pause at the corners.
As Martin mentioned, it might be best to have a chat with your machine tool supplier and ask if anything can be done
to speed up execution of the code. Possible causes are:
The machine could be operating in exact stop mode.
(Is there a G61 in the header?, if yes, does the machine support a distance tolerance?)
A line buffer taking time to empty, if the machine supports arc moves, adding these to the post processor would usually reduce the number
of lines required to travel around the corner. Either way your machine tool supplier should be able to advise.

The 'missing' X,Y values are almost certainly because the X,Y value has not changed for that particular line.
They can be added by changing the post processor to always output values whether changed or not, but if the problem that you are seeing with your machine is due to a line buffer problem, this has the potential to exacerbate rather than cure any problem you are seeing.

Cheers,

Mark.

[Heritage820]

Hi Mark, thanks for the response!

There is no G61 in the header, so its not that. ]

My machine does support arc's and there is a post available for my machine, however, the arcs post does not support tool changes and I would have to run separated programs for every tool.

Getting support for my machine is not the easiest, but I will try that also. I run programs on my machine daily that are generated with other software and I don't have this problem. Only when I run the vectric software.

[Adrian]

If you have code that doesn't show this problem then comparing that code with the code produced by the post processor in VCarve should give you a good idea of where the issue is.

If you're not sure on what to look for then you can attach both code files here and people can compare them for you.

[martin54]

There is a post-processor editing guide under the help tab if you are able to modify a post-processor yourself so you create a post-processor that supports arcs & ATC, I can't help with that personally but sure one of the experts on it could

[tomgardiner]

My guess is that this is an acceleration/decceleration issue within the control. I have no idea why V Carve would perform differently from other sources of code.
As a test, try adding a .001" radius on the corners of a test piece and see if the dwell is reduced or eliminated. The sharp corner may be caught in some calculations as an infinitely small radius.

[Heritage820]

There is a post-processor editing guide under the help tab if you are able to modify a post-processor yourself so you create a post-processor that supports arcs & ATC, I can't help with that personally but sure one of the experts on it could

Wow I didnt know you can modify the post, sounds ultra complicated. Maybe I can find an expert here. Thanks!

[Heritage820]

My guess is that this is an acceleration/decceleration issue within the control. I have no idea why V Carve would perform differently from other sources of code.
As a test, try adding a .001" radius on the corners of a test piece and see if the dwell is reduced or eliminated. The sharp corner may be caught in some calculations as an infinitely small radius.

That's a great idea, I will try that and get back to this thread

[Heritage820]

If you have code that doesn't show this problem then comparing that code with the code produced by the post processor in VCarve should give you a good idea of where the issue is.

If you're not sure on what to look for then you can attach both code files here and people can compare them for you.

Good idea, I will post both programs

[Rcnewcomb]

Wow I didnt know you can modify the post, sounds ultra complicated.

It sounds more complicated than it really it. It is all done with a text editor. The post processor editing guide (under Help) can walk you through it.