Author Topic: G-Code Just Cutting Circles  (Read 182 times)

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Offline gyrojeremy

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G-Code Just Cutting Circles
« on: January 18, 2019, 03:11:53 AM »
Hey all.
I'm in the process of converting my mill to CNC. I've got clearpath servos x, y, z run by ESS controller using Mach4. Today was the first test using a gcode file produced by Fusion 360. Basically it was meant to do about 6 passes  to make a square block round and drill 6 holes. It kind of made it round but it used circle cuts on the outside to achieve this. And the hole drilling would have shared the drill on the first hole.

Has anyone seen this before? Any suggestions as to where I when wrong?


Cheers,
J
« Last Edit: January 18, 2019, 03:22:59 AM by gyrojeremy »

Offline joeaverage

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Re: G-Code Just Cutting Circles
« Reply #1 on: January 18, 2019, 03:30:31 AM »
Hi,
just a guess but I think you are in the wrong Arc Center Mode.

Try changing it.....Configure/Control/General

Craig
My wife left with my best friend...
     and I miss him!

Offline gyrojeremy

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Re: G-Code Just Cutting Circles
« Reply #2 on: January 18, 2019, 04:21:36 PM »
Thanks Craig. I just checked and Incremental was ticked.
I'm wondering if it was something in fusion 360 as the servos were doing what the g-code was saying. Every line of code that included an "l" command like l23.00 or l39.00 in it, it would cut a circle with that diameter. Lines that had l00.24 would cause the x & y servos to fault but I think that's just tuning or trying to change direction to fast while trying to cut a circle diameter of 0.24mm.
Maybe I'll jump over to Fusion 360 forum and inquire. The tool path simulation didn't show the circles but it shows up in the g-code. This was my first attempt at anything like this so I'm sure it will be something simple that I've missed.
Cheers,
J
« Last Edit: January 18, 2019, 04:37:12 PM by gyrojeremy »

Offline joeaverage

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Re: G-Code Just Cutting Circles
« Reply #3 on: January 18, 2019, 04:55:45 PM »
Hi,
I suggested you change the setting from whatever it is at now to whatever. If the code then works you know you are working
in the right area.

In general most Mach Gcode is written with Arc Center Mode= Incremental and so you will have to adjust the Fusion
post processor to write the code in that way.

The first and simplest expedient to test it is to change the setting and try the same code.

Note if you change the setting you'll need to close Mach and then restart. The close/restart cycle flushes the change you have
made into the .ini file and the restart causes the new setting to be implemented.

Craig

My wife left with my best friend...
     and I miss him!

Offline Cbyrdtopper

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Re: G-Code Just Cutting Circles
« Reply #4 on: January 19, 2019, 12:27:47 AM »
Cutter compensation problem?   Share your G code file on here so we can try it out.   I've never had that kind of issue with my Fusion posts.
Chad Byrd

Offline gyrojeremy

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Re: G-Code Just Cutting Circles
« Reply #5 on: January 19, 2019, 12:41:43 AM »
Code is attached. Might be to big to put in this post. I'll change the  Arc Center Mode and re-run it now and let you know.

Offline joeaverage

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Re: G-Code Just Cutting Circles
« Reply #6 on: January 19, 2019, 02:15:52 AM »
Hi,
you can attach reasonable sized files, about 500k is recommended max. The real difficulty is when people attach
photos that they haven't resized and they are 3M!

Anyway I ran your code after changing the Arc Center Mode and ended up with a very different toolpath than you.
I can't quite anticipate the part that you are trying to make but I suspect the toolpath I've attached is closer to your
expectation.

Craig
My wife left with my best friend...
     and I miss him!

Offline gyrojeremy

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Re: G-Code Just Cutting Circles
« Reply #7 on: January 19, 2019, 03:28:43 AM »
Yeah sorry about over sized picture in my first post. It was just a screenshot so didn't think it would be so big. :o I'll see if I can edit it.

So yes, that is what it should look like. I changed the Arc Center Mode = Absolute and got the same results as you. Thank you for that Craig.

It was just a test to make a square block round. There was suppose to be some holes around the top but they didn't come through on my test ether. The program stopped on H0 maybe 10 lines before the end. I'll take a guess that H0 means hold for tool change maybe (I'll search that up after this) but there was not enough g-code left to peck drill 6 holes anyway. Might be the way I generated the file in fusion, ie; maybe I only high lighted the 3d adaptive?

Will keep trying new things now that it's working.

Cheers,
J
 

Offline gyrojeremy

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Re: G-Code Just Cutting Circles
« Reply #8 on: January 19, 2019, 03:53:51 AM »
It just dawned on me, that I haven't even downloaded the Mach4 post processor. My bad. I think I need to watch a few tutorials before I get to far ahead.

Offline joeaverage

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Re: G-Code Just Cutting Circles
« Reply #9 on: January 19, 2019, 04:37:35 AM »
Hi,

Quote
Yeah sorry about over sized picture in my first post. It was just a screenshot so didn't think it would be so big. :o I'll see if I can edit it.
Nonsense, the file was only 150k or so, that's fine.

It appears to me that you have two new pieces of software on the go.....do yourself a favour and drop one of them UNTIL
you have the other one sorted out.

Fusion is good but like ALL CAM programs they take a lot of learning. In this case for instance Fusion is producing code
which is not ideal for Mach and yet here you are on the Mach forum trying to sort it out. Ditch Fusion until you have
Mach4 sorted and doing its thing. THEN look at CAM options.

I would recommend NFS Mill Wizard ($75). It is a very simple way to generate conforming Gcode and allows you to do
a very wide range of tasks on your mill. How many times have you thought 'all I need to do is surface that piece
of material'. A very simple job. You don't need a full-blown CAM program to do it, a simple Wizard like MillWizard
can do it for you in minutes.

Download a copy and experiment with it, if you are not putting together files of three, four or more operations chained
together within half an hour......give up CNC and take up knitting!

Quote
I think I need to watch a few tutorials before I get to far ahead.
Hey, tutorials are good, but standing at your machine generating simple but conforming Gcode with a Wizard and then
having that Gcode cut material as you intended is VASTLY MORE VALUABLE THAN ANY TUTORIAL.

Craig
My wife left with my best friend...
     and I miss him!