3d cutting issues

[thephridge]

ran two different files still same outcome keep getting lines in the wood newbies to the cnc world so any help would be much appreciated

[martin54]

If you can provide a bit more info it might help, would be helpful if you could post the CRV file (copyright permitting)
What does the toolpath preview look like ? are there lines showing in that or does it look good.
Details on bit used, speed, feedrate strpover etc would be helpful if you can't post the file.
Have you tried rotating the stock so it cuts the grain in the opposite direction? You could also check your machine to ensure there is nothing slipping or any backlash

Only time I have had something similar myself was when my spindle wasn't running square & parallel to the table, traming the spindle sorted that problem

[IslaWW]

There is something loose in the Z axis. Grub screw, coupler, something. If not it's a static issue

[Leo]

There is no way to really know anything here because there is just not enough information.

But, I do see a couple of things.

1) The stepover is far too coarse.

2) the deep lines don't seem to be lost steps because it seems to correct itself. Lost steps would not correct.

Other than that, the lack of information just leaves us with nothing to help you with.

[ger21]

As Gary said, it's a mechanical issue.

[thephridge]

Thank you all. We're off for the weekend so we can send the info Monday. In the meantime, IslaWW, what do you mean by "static issue"?

[thephridge]

here is the crv file of the flower we were trying to cut none of the tool paths are in the file due to it being to big to upload onto here. our spindle speed is controlled on the actual router and is on the max speed it can do, and we are using a 1/16 inch ball nose bit for the finishing pass. Looked at the lines in the preview and nothing seemed to be an issue while it ran the preview tool paths. Hopefully this information will help a little bit more if more is needed just let us know what we can do, as i said before we are new at this and don't know much about this. thanks again.

[highpockets]

Preview looks OK so it is most likely not an issue with the model or VCP.
Two thoughts.
1 Are you sure you're using the correct Post Processor?
2 What is the feed rate?

[martin54]

Preview looks fine as highpockets has already said which would indicate that it is not a problem with the model or the software, not being able to view toolpaths doesn't help but as Leo has already said the stepover is to course for a finish pass, what stepover are you using ? I would also think you could slow the router down but that won't give an improved finish, just make your router last longer You said max speed, what is that for your particular router ?

No experience with static problems & have only seen that sort of irregular line pattern when my spindle was out of tram but it wasn't anywhere near as deep as those appear to be

[Mark]

Hello thephridge,

On an earlier post, you mentioned that you have Mach4 control software on one machine and LinuxCNC on another machine.
Both of these control software packages include a toolpath preview.
With ridges as deep as the ones that you are seeing, if the problem were in the toolpaths, you would see the ridges within the
toolpath preview on the machine control software.
As Gary and Gerry have pointed out, the most likely cause of the problem would be mechanical, perhaps the feed rate is too fast
for the Z axis, or some slack in the travel.

I hope that this helps.

[Arnell]

I have seen a similar problem with a laser engraver. A notebook computer was used on the machine and the problem turned out to be the computer was going into power saving mode.

Hope this helps.

[martin54]

I have seen a similar problem with a laser engraver. A notebook computer was used on the machine and the problem turned out to be the computer was going into power saving mode.

Hope this helps.

Just to add to this because sometimes turning off or disabling power saving features is not enough
From your profile it looks like you have a home built machine, so how much you need to optimise your computer will depend on a number of different factors like what operating system you are using, what control software, the type of motion control & how that is connected to your computer are all factors.
As an example Mach3 running via parallel port control does not like anything else going on in the background so the best set up would be a computer stripped of just about everything other than mach3 with no internet connection, anti virus software & anything to do with operating system updates turned off

[thephridge]

This is all good information. Thank you. It's not difficult to switch to a stripped down PC. Let's hope it's that easy cuz we can't find anything mechanically loose. We are going to use a dial indicator in the next day or so to see what we can see.

[thephridge]

I have seen a similar problem with a laser engraver. A notebook computer was used on the machine and the problem turned out to be the computer was going into power saving mode.

Hope this helps.

Just to add to this because sometimes turning off or disabling power saving features is not enough
From your profile it looks like you have a home built machine, so how much you need to optimise your computer will depend on a number of different factors like what operating system you are using, what control software, the type of motion control & how that is connected to your computer are all factors.
As an example Mach3 running via parallel port control does not like anything else going on in the background so the best set up would be a computer stripped of just about everything other than mach3 with no internet connection, anti virus software & anything to do with operating system updates turned off

This is all good information. Thank you. It's not difficult to switch to a stripped down PC. Let's hope it's that easy cuz we can't find anything mechanically loose. We are going to use a dial indicator in the next day or so to see what we can see.

[martin54]

Have you checked for backlash & any free play in your ballscrew/leadscrew through the full range of the z axis? Is your machine earthed properly because Gary is one of the board experts so if he says it may be static then that is something worth checking.
I would also check the spindle is trammed correctly, that is something that you want to do anyway as part of your machine maintenance program

After I had repaired/rebuilt my CNC I skimped on the motion control which I really shouldn't have done, I ran mach3 on a windows XP machine & the cnc was conected to the computer via parallel port, having read lots of posts on the mach support forum about people having problems I made sure the computer was stripped down & the only program installed was mach3, I optimised the computer by using settings from Black Viper who I had read about on this forum.
Now my set up is completely different, I am running UCCNC & mach3 on a windows 7 computer, the CNC is connected to the computer by an Ethernet motion control board & I have had to do very little to the computer
Auto updates & power saving features are turned off but that is about all, have the vectric software installed on the computer along with a couple of other programs