Dynomotion

Group: DynoMotion Message: 10266 From: Sam Marrocco Date: 10/8/2014
Subject: Rotational Axes & Radius relationship
I have an axis (A) that is set to degrees mode. To enable Gcode script operation (per a previous post) it was suggested that the RadiusA needed to be set to a "reasonable radius" to allow the Trajectory Planner to determine the feed rate properly. I did so, and this enabled GCode that called for motion of the A Axis.

However, I've noticed that I cannot make the A Axis rotate very fast with GCode. Jogging and other non-interpolated operations all seem to be operating normally and very quickly (when called for). Simple code such as:

G1 F.1 A360

and

G1 G30 A360

...behave nearly the same.

I have tried changing the RadiusA to other values such as 0, .1, 1, 10, 100 but that makes only slight changes. I seem unable to make the rotation (of my rotary table in this case) move faster than 1 degree/sec. Without gcode I can rotate it hundreds of degrees/sec. Any suggestions as to what might be causing this?

What is the actual definition of RadiusA? Is it the radius (inches if in Inch mode) of the outer diameter of the rotary table if that's there the speed is to be measured/referenced?

I'm using KMotion433c with my KFlop.

--

sam marrocco | chief technical officer
ringside.cutters.picnic.moonlink

248 548 2500 w
248 910 3344 c

ringsidecreative.com
Group: DynoMotion Message: 10269 From: Tom Kerekes Date: 10/8/2014
Subject: Re: Rotational Axes & Radius relationship
Hi Sam,

What are your Trajectory Planner Settings?

Yes the radius is used to translate linear speed at that radius to angular speed of the axis.  So for example if you specify a radius of 2 inches and command a speed of 100 inch per minute the angular speed would be:

Angular speed = Linear Speed / (2Pi * R) = 100ipm / (2Pi * 2) = 7.96 rad/min = 456 deg/min = 7.60 deg/sec

Regards
TK
.
Group: DynoMotion Message: 10270 From: Sam Marrocco Date: 10/8/2014
Subject: Re: Rotational Axes & Radius relationship

On 10/8/2014 1:53 PM, Tom Kerekes tk@... [DynoMotion] wrote:
 
Hi Sam,

What are your Trajectory Planner Settings?


A Motor Counts/degree: 400
Velocity deg/sec: 100,000
Accel Deg/sec2: 200,000
Degrees=True
Radius Inches=1
Interpreter Length Mode=inch




sam marrocco | chief technical officer
ringside.cutters.picnic.moonlink

248 548 2500 w
248 910 3344 c

ringsidecreative.com
Group: DynoMotion Message: 10272 From: Tom Kerekes Date: 10/8/2014
Subject: Re: Rotational Axes & Radius relationship
Hi Sam,

Those are big number so they should not be limiting speed.

You are specifying a Feed rate of 0.1 inches/minute.  That would be very slow.  For a Radius of 1 inch it would be:

0.1ipm / (1inch x 2Pi) =  0.0159 rad/minute = 0.912 deg/minute = 0.0152 degrees/sec

But the speed should change with the specified radius in the Trajectory Planner Screen.  You said it changes "slightly"  What does that mean?

Try specifying a much higher Feedrate.

Post the Radius you are specifying, the Feedrate Specified, and the Rate you are observing.

Regards
TK

Group: DynoMotion Message: 10276 From: Sam Marrocco Date: 10/9/2014
Subject: Re: Rotational Axes & Radius relationship

On 10/9/2014 1:17 AM, Tom Kerekes tk@... [DynoMotion] wrote:
 
Hi Sam,

Those are big number so they should not be limiting speed.

You are specifying a Feed rate of 0.1 inches/minute.  That would be very slow.  For a Radius of 1 inch it would be:

0.1ipm / (1inch x 2Pi) =  0.0159 rad/minute = 0.912 deg/minute = 0.0152 degrees/sec

But the speed should change with the specified radius in the Trajectory Planner Screen.  You said it changes "slightly"  What does that mean?

Try specifying a much higher Feedrate.

Post the Radius you are specifying, the Feedrate Specified, and the Rate you are observing.



Here are some examples:

Using:
A Motor Counts/degree: 400
Velocity deg/sec: 100,000
Accel Deg/sec2: 200,000
Degrees=True
Radius Inches=1
Interpreter Length Mode=inch

All speeds are approximate, gauged by watching the DRO

G01 F.01 A360	(~.01 degrees/sec)
G01 F.1 A360 	(~.1 degrees/sec)
G01 F1 A360	(~1 degrees/sec)
G01 F2 A360	(~1 degrees/sec)
G01 F10 A360	(~1 degrees/sec)
G01 F50 A360	(~1 degrees/sec)
G01 F100 A360	(~1 degrees/sec)
G01 F1000 A360	(~1 degrees/sec)

It looks like slow feedrates, less than or equal to 1 are working, but feedrates larger than 1 are capped or clipped at 1 degree/sec.
Just as a reminder, this is all being done through KMotion dotnet.




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sam marrocco | chief technical officer
ringside.cutters.picnic.moonlink

248 548 2500 w
248 910 3344 c

ringsidecreative.com