Rough Motion on Circular Toolpaths

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spikee
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Re: Rough Motion on Circular Toolpaths

Post by spikee »

for a servo loop, afaik it is easier to control it at high speed vs low speed. Hence why a certain gearing is recommended.
With bigger servos this is less of an issue due to it just having more torque.
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Re: Rough Motion on Circular Toolpaths

Post by Salted_Pork »

Not sure if this changes anything, but I learned that these are not servos, they are “hybrid steppers/servos”, which is just a stepper with an encoder.
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Re: Rough Motion on Circular Toolpaths

Post by Salted_Pork »

cnckeith wrote: Thu May 16, 2024 7:02 pm
no need to have smoothing ON with this type of g code. smoothing is for short vector g code. not G2's/g3's
see this for more info.
https://www.centroidcnc.com/centroid_di ... manual.pdf

fyi..smoothing Will NOT make up for bad gearing or other mechanical issues.
Hi Keith,

So when I turn smoothing OFF aka exact stop, it runs really bad especailly as the feedrate increases.

see video:

https://photos.app.goo.gl/1GQ9xdanfwb1C2ct9

When any smoothing setting is turned on, it runs /relatively/ smooth and at the correct feedrate.

For simple arc moves it seems this should not bog down the controller.

I attached a current report.
Attachments
report_54453804251C-0118247882_2024-05-24_12-46-00.zip
(1.1 MiB) Downloaded 2 times
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Re: Rough Motion on Circular Toolpaths

Post by cnckeith »

Salted_Pork wrote: Fri May 24, 2024 2:49 pm
cnckeith wrote: Thu May 16, 2024 7:02 pm
no need to have smoothing ON with this type of g code. smoothing is for short vector g code. not G2's/g3's
see this for more info.
https://www.centroidcnc.com/centroid_di ... manual.pdf

fyi..smoothing Will NOT make up for bad gearing or other mechanical issues.
Hi Keith,

So when I turn smoothing OFF aka exact stop, it runs really bad especailly as the feedrate increases.

see video:

https://photos.app.goo.gl/1GQ9xdanfwb1C2ct9

When any smoothing setting is turned on, it runs /relatively/ smooth and at the correct feedrate.

For simple arc moves it seems this should not bog down the controller.

I attached a current report.
post the g code program. the last one had very very short moves, so short that it was beyond necessary. adjust the minimum vector length in the cad/cam system so it doesn't put out .002" moves :D
Need support? READ THIS POST first. http://centroidcncforum.com/viewtopic.php?f=60&t=1043
All Acorn Documentation is located here: viewtopic.php?f=60&t=3397
Answers to common questions: viewforum.php?f=63
and here viewforum.php?f=61
Gear we use but don't sell. https://www.centroidcnc.com/centroid_di ... _gear.html
cnckeith
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Re: Rough Motion on Circular Toolpaths

Post by cnckeith »

Need support? READ THIS POST first. http://centroidcncforum.com/viewtopic.php?f=60&t=1043
All Acorn Documentation is located here: viewtopic.php?f=60&t=3397
Answers to common questions: viewforum.php?f=63
and here viewforum.php?f=61
Gear we use but don't sell. https://www.centroidcnc.com/centroid_di ... _gear.html
Salted_Pork
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Re: Rough Motion on Circular Toolpaths

Post by Salted_Pork »

[/quote]

post the g code program. the last one had very very short moves, so short that it was beyond necessary. adjust the minimum vector length in the cad/cam system so it doesn't put out .002" moves :D
[/quote]

Heres the relevant code for the circle:

(2D Contour9 (6))
N240 G0 X-4.0125 Y8.9505
N245 Z0.788
N250 Z0.388
N255 G1 Z0.258 F300.
N260 G18 G3 X-4.1125 Z0.158 I-0.1 K0. F200.
N265 G1 X-4.125
N270 G17 G2 Y12.2995 I0. J1.6745
N275 Y8.9505 I0. J-1.6745
N280 G1 X-4.1375
N285 G18 G3 X-4.2375 Z0.258 I0. K0.1
N290 G0 Z0.788
N295 G17
N300 M9
N315 M30

Not seeing any tiny .002" moves... Unless I don't understand how these arc moves work.
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Re: Rough Motion on Circular Toolpaths

Post by suntravel »

Your router is not running in the recommended turns/inch range and the motors are vibrating at low speed.

Smoothing is not the right medicine to cure this ;)

At least add gearing to bring it in the recommended sweet spot, this will also avoid the slow vibrating speed of the motors.

Uwe
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Re: Rough Motion on Circular Toolpaths

Post by Salted_Pork »

suntravel wrote: Fri May 24, 2024 5:15 pm Your router is not running in the recommended turns/inch range and the motors are vibrating at low speed.

Smoothing is not the right medicine to cure this ;)

At least add gearing to bring it in the recommended sweet spot, this will also avoid the slow vibrating speed of the motors.

Uwe
Yeah just ordered some gear reducers, so working on that, hopefully fixes my problem (fingers crossed).

But regardless of gearing, i find it weird that i cant run simple programs without smoothing turned on, so i'm trying to figure that part out too.
suntravel
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Re: Rough Motion on Circular Toolpaths

Post by suntravel »

A good smooth circle is not so simple, but this will be solved if the machine is running in the sweet spot if it is mechanical ok.

Uwe
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Re: Rough Motion on Circular Toolpaths

Post by Salted_Pork »

Salted_Pork wrote: Fri May 24, 2024 5:08 pm
Not seeing any tiny .002" moves... Unless I don't understand how these arc moves work.
Keith any ideas on this?
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