G-Code Generates with Unwanted Random Circular Paths

[Anonymous]

Hi, 

First of all, I like to say that I submitted this same post on the HSM Post Processing forum... thinking that maybe it would be the best place to get some feedback. But since im using F360, I think i better post it here too. Hope I'm not breaking any forum rules. 

The issue: Im running a post processor that I found here in the forums - created by another Autodesk member (employee I believe). I'm running a CNCmasters mill which utilizes the MasterMX CNC software. I've had the machine for about 3 months now and so far I have had 0 problems when I post out simple 2d cam operations. I 've started to work into more complex 3d geometry lately and have had a very annoying recurring problem. Every time I use 3DAdaptive or 3D pocket and post out I get random unexpected circular paths that spoils my work and or crashes my end mills. It seems to be more common with intricate paths such as those from engraving operations.  

Examples:

MasterMX Path simulation

F360 Path simulationI believe the issue derives from the current post processor I am using. I've been doing my best to troubleshoot the issue; trying to find any pattern in the code that would help me find a solution. No luck so far. It seems like the lines creating the erratic circles have nothing in common that would point to the culprit. Well aside the fact that they are either G02 or G03. The format for arcs and helical moves is X_Y_I_J.  

Here is what the MasterMX software manual says:

“Format: X__Y__I__J__.  I, J are relative distance from start to center. Incremental Z can be added for helical designs.   Important:  The G02/03 commands must be written with X value, Y Value, I Value, and J value on every line for it to work properly.  If you place a Z coordinate on the same line, that will command the toolpath to run a helical program with X Y and Z running at the same time.”

I underlined what I believe could be the issue. Some of the G02 and G03 lines generated by the pp come out either missing an x, or y, or both. I did some troubleshooting picking out some of the defective lines of code but I have not arrived to a clear conclusion – I'm still working on it.

I’ve also been trying tweaking different operation parameters within F360. Adjusting the minimum radii, chord lengths, and anything but I have not been able to get rid of the circles completely. They just either get bigger, or more show up. I’ve also tried disabling helical moves which generates the code using just G01 (x,y,z)  moves only. To my surprise, this did nothing at all. The PP generated the same number of circles but with G01 moves… which now that I think about it, it destroys my theory about G02 and G03 being generated incorrectly.

I would really appreciate it if someone could help me out. Maybe there is a parameter I am missing… or not. If anyone has the slightest suggestion, I will take it. Im at a lost.

Link to where I found the PP: Link

I'll attach the actual PP file if anyone needs it. 

I guess i will also attach the F360 file. 

Thank you, 

JG

** UPDATE** 

I tried to just use 2d adaptive cleaning and that seemed to help a bit, except I still got 2 circles messing with my work. So i guess the issues isn't related to just 3D operations. 

[daniel_lyall]

Have you tried with feed optimation turned off.

Change the settings in the pre-post dialog to what is below and the big crop circles will go away

[daniel_lyall]

I have attached your file with some adjustments made to it have a look through use it as a reference, some of the settings I am guessing was you just trying to find the problem.

With this sort of thing, it can be a user error what can help is right clicking on a toolpath tab and resetting it to default, you can do this with the pre-post dialog as well.  

[Anonymous]

Hi Daniel, 

Thanks for your help. I went ahead and opened the file and posted out. It doesn't seem like much changed after posting out, circles just moved around. I'll attach images of what it looks like within the MasterMx software. I believe the issue might be in the post processor... but yet again, i wouldn't know what to change.

I'm so novice that I couldn't tell you what you changed, maybe some of the ramping parameters? I've also noticed that the first 3d adaptive operation no longer has any paths - empty tool path.  You are right though, i've been making a mess trying to figure out the issue. 

Again, any help is welcomed. Thanks

Images:Pocket1 in fusion

Pocket1 after post, in Mx controller

Pocket2 in fusion

Pocket2 after post, in Mx controller

[Anonymous]

Daniel, 

You are the beesneez!

Sorry, I didnt see your first post, just the second one. The pre-post parameters did the trick. I'm just wondering how?  I'm really curious to learn more about these settings. What exactly does Pi have to do with the high feedrate? I'm guessing that's just a random number you chose? Does changing it overwrite any other speeds set previously within fusion360 cam? Also, would I need to change these settings again for different setups? Or should they work for all? Either way, seriously, I appreciate all the help! 

Thanks again! 

-JG 

FIXED!

[daniel_lyall]

They are the default settings.

[HughesTooling]

@daniel_lyall  Are those setting correct? You have the maximum circular rad set to 0.01 and the minimum set to 0.01, I'd guess with those setting you will not get any arcs. 

I think the problem is the minimum cord length, I would set it to 0.1 or 0.2 and reset the maximum rad to 1000 or whatever it was before. Some controls don't like very short arcs and do a full circle, setting the minimum cord length to a bigger size usually fixes the problem.

Mark

[daniel_lyall]

It defaulted to those settings, what is strange is the settings have changed by there self.

[daniel_lyall]

This is what it shows now with the change @HughesTooling  did and it is fine @Anonymous  please make sure it looks like this now.

Leason for me, do not believe the default is correct.

[Anonymous]

big thanks to daniel_lyall that worked!

had huge circles all over my winpc-nc, changed cord length in fusion from 0.25 to 0.1 as you said and now 

allis good

Thanks again 

Dan

[guy.eddington]

Hi @daniel_lyall and others,

I wonder if anyone could help me too. 

I’m also having issues with unwanted circular tool paths after post processing from Fusion 360 to our CNC router, and it’s only since I had my PC upgraded by our IT department last week. The weird thing is that the set-up appears to be exactly the same as it was before - same post processor (AXYZ), same configuration settings etc. 

My IT dept. have no idea and nor do the CNC suppliers who gave us the post processor software. 

Please see attached photos of tool path preview featuring unwanted circles everywhere, and configuration settings before I changed PC’s (settings exactly the same now)

If anyone could suggest some possible solutions I’d be really appreciative. 

Thanks, 

Guy