Moderators: TomKerekes, dynomotion

Ukr-Sasha
Posts: 8
Joined: Tue Jan 23, 2018 5:39 am

Hi everybody.
The question is rather to the developer Tom.
Here is an example of my simple code:

Code: Select all

``````G21 G90 G17
G49 G40
F100
G0 X0 Y0
G2 X60.0000 Y10.0000 I10.0000 J0.0000
M30``````
And when simulating the scheduler gives an error.
Although the radius of the arc is an integer and there should be no error.
Arc accuracy settings in the picture.
I can not understand what the problem is .....
Attachments

TomKerekes
Posts: 651
Joined: Mon Dec 04, 2017 1:49 am

### Re: Arc begin/end radius tolerance

Hi turbothis,

This GCode defines a circle center at 10,0 (previous XY + IJ).

To create an arc starting at 0,0 (previous XY)

the arc should then end at 60,10 (new XY)

This is clearly impossible!

Arc.PNG (7.62 KiB) Viewed 589 times

HTH
Regards,

Tom Kerekes
Dynomotion, Inc.

Ukr-Sasha
Posts: 8
Joined: Tue Jan 23, 2018 5:39 am

### Re: Arc begin/end radius tolerance

Yes indeed.
The starting point of the arc must be in coordinates X50 Y0.
I'm just trying to understand how this feature works.
But here is the code section with the real path of the part processing.
And it does not work.
Attachments

TomKerekes
Posts: 651
Joined: Mon Dec 04, 2017 1:49 am

### Re: Arc begin/end radius tolerance

Hi turbothis,

Do the math for those values. Calculate the center point and then distance to beginning and end.
Regards,

Tom Kerekes
Dynomotion, Inc.

Ukr-Sasha
Posts: 8
Joined: Tue Jan 23, 2018 5:39 am

### Re: Arc begin/end radius tolerance

I did the calculations.
The difference in the distances to the beginning and to the end of the arc is 0.000289065 mm. This is more than the accuracy of the arc in the settings 0.00000254mm.
Therefore a mistake? I understood correctly?
Need to set up a CAM system and a postprocessor?
Attachments

TomKerekes
Posts: 651
Joined: Mon Dec 04, 2017 1:49 am

### Re: Arc begin/end radius tolerance

The GCode only specifies 3 decimal digits which means the GCode will contain round off errors up to +/-0.5um. So your error calculation of 0.289um makes sense. You should probably set the error tolerance to 1um or more. This would be:

1um = 0.001mm * (1inch/25.4mm) = 3.93e-5 inches
Regards,

Tom Kerekes
Dynomotion, Inc.

Ukr-Sasha
Posts: 8
Joined: Tue Jan 23, 2018 5:39 am

Thank you Tom.
I will try it.