Rotating degrees/min

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Rotating degrees/min

Postby JMD » Fri Jun 28, 2019 12:46 pm

Just set up rotary axis on my Probotix G2525. Using V-Carve Pro. A axis is moving in degrees per minute. Is there a way to change it to inches per minute. Right mow it is way to slow.
Also, I am using the Probotix post processor.
Thank you,
John
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Re: Rotating degrees/min

Postby IslaWW » Fri Jun 28, 2019 12:50 pm

No. If it is a rotary degrees per minute is the unit of choice. But there is a conversion to get the surface speed equivalent to an XY feedrate.

115 * (XY Feedrate) / (Blank diameter).

Example: 100 IPM and 2" diameter blank: 115 * 100= 11500 /2 = 5750 degrees per minute
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Re: Rotating degrees/min

Postby 4DThinker » Fri Jun 28, 2019 1:33 pm

I do frequent rotary jobs for my students. For whatever bit I'm using I set the feed rate to 4000. That gets the A axis turning reasonably fast, but Y and Z moves are still limited by the hardware settings. No need to calculate a speed for every unique job. I use the feed speed slider to tweak the speed based on the current cut. Sometimes an initial plunge needs to be slowed down but all following movement can run full speed. Full bitwidth pass VS stepover pass.

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Re: Rotating degrees/min

Postby JMD » Fri Jun 28, 2019 4:02 pm

Thank you for the replays. I will give it a try.
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Re: Rotating degrees/min

Postby TReischl » Sat Jun 29, 2019 1:18 am

Hmmm, interesting. Not sure what the shark is using or the probotix for control software? I run Mach 3 and the feedrate is set by the control for the linear axis and the rotary. I recall having to set a couple things in the config page but after that I have not had to concern myself with how fast the rotary is turning.

It would seem to me that it would be problematic to have to calculate degrees/min based on the current diameter because in a rotary job there can be a lot of diameters and even diameters that are constantly changing. Think "oval" handle shapes.
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Re: Rotating degrees/min

Postby Greolt » Sat Jun 29, 2019 2:22 am

Does the Probotix control support G93 code?

A lot of controllers have inbuilt methods to compensate rotary axis feedrate. Mach3 does.

Almost all controllers will support G93 code.

Vectic software will output G93. Not sure all versions do.
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Re: Rotating degrees/min

Postby JMD » Sat Jun 29, 2019 12:06 pm

4DThinker wrote:I do frequent rotary jobs for my students. For whatever bit I'm using I set the feed rate to 4000. That gets the A axis turning reasonably fast, but Y and Z moves are still limited by the hardware settings. No need to calculate a speed for every unique job. I use the feed speed slider to tweak the speed based on the current cut. Sometimes an initial plunge needs to be slowed down but all following movement can run full speed. Full bitwidth pass VS stepover pass.

4D

Tried this and it seems to doing a good for now. Will use it wile I look for other ways to get the job done.
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Re: Rotating degrees/min

Postby JMD » Sat Jun 29, 2019 12:11 pm

TReischl wrote:Hmmm, interesting. Not sure what the shark is using or the probotix for control software? I run Mach 3 and the feedrate is set by the control for the linear axis and the rotary. I recall having to set a couple things in the config page but after that I have not had to concern myself with how fast the rotary is turning.

It would seem to me that it would be problematic to have to calculate degrees/min based on the current diameter because in a rotary job there can be a lot of diameters and even diameters that are constantly changing. Think "oval" handle shapes.


Probotix uses LinuxCNC. I also think that having to calculate degrees/min is a little too much. Just getting started with rotary on the CNC. Have a lot of thing to learn yet.
Thank you for the help.
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Re: Rotating degrees/min

Postby JMD » Sat Jun 29, 2019 12:15 pm

Greolt wrote:Does the Probotix control support G93 code?

A lot of controllers have inbuilt methods to compensate rotary axis feedrate. Mach3 does.

Almost all controllers will support G93 code.

Vectic software will output G93. Not sure all versions do.


Do not know enough about G-Code yet to know this. I am still learning and will check into it.
Thank you for all the help.
And a BIG thank you to all the people on the forum. I can always count on you for help. :) :)
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Re: Rotating degrees/min

Postby IslaWW » Sun Jun 30, 2019 12:47 am

JMD...
Each controller can provide a slightly different way to set or "combine" rotary axis speeds. Like Greolt says, G93 would be a good way to get predictable feedrates to your tools. As irritating as an extremely slow speed can be, imagine one that is too fast and you break bits in a second or two.

There is no advantage to not knowing what your rotary feedrates are and having the ability to change them to suit a particular job. That said, many that don't understand the principle or know how to do it may often say its not important. I disagree. It is the same principle as being able to set your X axis feedrate and spinning a wheel to select some random Y feedrate.
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