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Author Topic: Constant Velocity vs Exact Stop  (Read 3538 times)

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Offline kolias

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Constant Velocity vs Exact Stop
« on: November 28, 2015, 07:12:33 PM »
On Mach3 Config / General Config / Set the Motion Mode, the choice is Constant Velocity or Exact Stop.

What is the recommended setting of this parameter for a cnc?
Nicolas

Offline ger21

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Re: Constant Velocity vs Exact Stop
« Reply #1 on: November 28, 2015, 10:00:30 PM »
Depends on the type of CNC.
For almost all, though, it's Constant Velocity
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: Constant Velocity vs Exact Stop
« Reply #2 on: November 28, 2015, 10:15:16 PM »
Exact stop means every move will come to a complete stop before executing the next move so the path will be exact. When there are lots of short moves the machine will sometimes appear to stutter. Continuous will attempt to keep the machine in motion so there may be corner rounding or overshoot depending on the speed. Both have their place.

Offline kolias

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Re: Constant Velocity vs Exact Stop
« Reply #3 on: November 29, 2015, 07:37:32 AM »
Thank you both for your time
Nicolas

Offline ger21

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Re: Constant Velocity vs Exact Stop
« Reply #4 on: November 29, 2015, 07:40:25 AM »
There are numerous CV settings to minimize or eliminate corner rounding.
The best starting point is to turn CV on, but turn off all CV options in General Config and the Settings page.
Except.
In General Config, check "Stop CV on Angles >" and set it to 89. This works very well for most people, in most cases.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html

Offline kolias

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Re: Constant Velocity vs Exact Stop
« Reply #5 on: November 29, 2015, 07:47:39 AM »
I will try this when I get the cnc going
Nicolas