Hello,

I'm pretty sure the answer is no but is there anyway to control an
ethercat drive from kflop/kanalog?

My limited googling leads me to believe that EtherCat drives get their
speed/torque commands via ethernet from an ethercat "master", typically
a PC (or dedicated controller) handling the motion control.

I want to add a third axis to my saw to position the guide wheels, like
this: https://youtu.be/vy7ar2x4no8?t=1m10s FWIW this is one of the
nicest CNC wire saws I've seen. Basically the guide wheels are rotated
so that they stay parallel to the motion. What most saws use is a
hollow shaft gearbox with flange to attach the wheels to. I've found
some gearbox's that have Beckhoff servo's attached on ebay, the seller
also has matching Beckhoff EtherCat drives.

Given the answer is no, has anyone used a Beckhoff servo with another
drive? Only thing I'm unsure of is the feedback interface on the servo,
the documentation states
(https://www.beckhoff.com/english.asp?drive_technology/am3041.htm , full
part number AM3041-0H41-0000 ) :

"multi-turn absolute encoder, BiSS, absolute position within 4,096
revolutions, electronic identification plate, AM302x…AM308x: 2,048 sine
periods per revolution"

Is a BiSS encoder compatible with most drives?

Sorry I realize this isn't a Kflop question, just hoping those with more
experience with servos and drives might know if is worth pursuing the
Beckhoff motors.

Thanks

Greg.

 

Hi Greg,

I’ve done several contour wire saws with rotating guide wheels that keep the wheels tangent to the cut.  I use an off the shelf 3ph motor and any AC drive that will accept a bi-polar input for speed and direction.  I remove the fan from the motor and replace it with a 2 lobe cam that will pulse 2 proximity switches.  The switches are mounted such that the 2 outputs will produce a quadrature output identical to what an encoder produces.  This will give you 8 pulses per rev at the motor.  Guide wheel gear boxes are usually around 100:1 so you would get 800 pulses per rev of your wheels yielding ~ 1 degree of accuracy.  I’ve found that even as much as 5 deg to be fine for guide wheels.

 Shannon

On Thu, Jan 12, 2017 at 9:25 AM, Greg Carter greg@... [DynoMotion] <DynoMotion@yahoogroups.com> wrote:

 

Hello,

I'm pretty sure the answer is no but is there anyway to control an
ethercat drive from kflop/kanalog?

My limited googling leads me to believe that EtherCat drives get their
speed/torque commands via ethernet from an ethercat "master", typically
a PC (or dedicated controller) handling the motion control.

I want to add a third axis to my saw to position the guide wheels, like
this: https://youtu.be/vy7ar2x4no8? t=1m10s FWIW this is one of the
nicest CNC wire saws I've seen. Basically the guide wheels are rotated
so that they stay parallel to the motion. What most saws use is a
hollow shaft gearbox with flange to attach the wheels to. I've found
some gearbox's that have Beckhoff servo's attached on ebay, the seller
also has matching Beckhoff EtherCat drives.

Given the answer is no, has anyone used a Beckhoff servo with another
drive? Only thing I'm unsure of is the feedback interface on the servo,
the documentation states
(https://www.beckhoff.com/ english.asp?drive_technology/ am3041.htm , full
part number AM3041-0H41-0000 ) :

"multi-turn absolute encoder, BiSS, absolute position within 4,096
revolutions, electronic identification plate, AM302x…AM308x: 2,048 sine
periods per revolution"

Is a BiSS encoder compatible with most drives?

Sorry I realize this isn't a Kflop question, just hoping those with more
experience with servos and drives might know if is worth pursuing the
Beckhoff motors.

Thanks

Greg.

 

"...what did they cut? Stone?" Yes, granite.  Swenson Granite & Rock of Ages Barre, VT.  We made the WWII memorial and cut a lot of the stone with our contour saws.

On Thu, Jan 12, 2017 at 1:47 PM, Greg Carter greg@... [DynoMotion] <DynoMotion@yahoogroups.com> wrote:

 

Hi Shannon,

That is great that you've built contour saws before, what did they cut? Stone?

I'm currently using AC induction motors and VFD's for the X and Y axis controlled via kanalog +-10v outputs with linear draw wire encoders for feedback.  I thought I would try true servo's on these axis just to get experience but it will probably be easier and cheaper to find AC induction motors and drives. 

Thanks for your insight.
Greg.

On 1/12/2017 10:27 AM, Shannon Davenport sdavenport.roa@... [DynoMotion] wrote:

 

Hi Greg,

I’ve done several contour wire saws with rotating guide wheels that keep the wheels tangent to the cut.  I use an off the shelf 3ph motor and any AC drive that will accept a bi-polar input for speed and direction.  I remove the fan from the motor and replace it with a 2 lobe cam that will pulse 2 proximity switches.  The switches are mounted such that the 2 outputs will produce a quadrature output identical to what an encoder produces.  This will give you 8 pulses per rev at the motor.  Guide wheel gear boxes are usually around 100:1 so you would get 800 pulses per rev of your wheels yielding ~ 1 degree of accuracy.  I’ve found that even as much as 5 deg to be fine for guide wheels.

 Shannon

On Thu, Jan 12, 2017 at 9:25 AM, Greg Carter greg@... [DynoMotion] <DynoMotion@yahoogroups.com> wrote:

 

Hello,

I'm pretty sure the answer is no but is there anyway to control an
ethercat drive from kflop/kanalog?

My limited googling leads me to believe that EtherCat drives get their
speed/torque commands via ethernet from an ethercat "master", typically
a PC (or dedicated controller) handling the motion control.

I want to add a third axis to my saw to position the guide wheels, like
this: https://youtu.be/vy7ar2x4no8?t =1m10s FWIW this is one of the
nicest CNC wire saws I've seen. Basically the guide wheels are rotated
so that they stay parallel to the motion. What most saws use is a
hollow shaft gearbox with flange to attach the wheels to. I've found
some gearbox's that have Beckhoff servo's attached on ebay, the seller
also has matching Beckhoff EtherCat drives.

Given the answer is no, has anyone used a Beckhoff servo with another
drive? Only thing I'm unsure of is the feedback interface on the servo,
the documentation states
(https://www.beckhoff.com/engl ish.asp?drive_technology/am304 1.htm , full
part number AM3041-0H41-0000 ) :

"multi-turn absolute encoder, BiSS, absolute position within 4,096
revolutions, electronic identification plate, AM302x…AM308x: 2,048 sine
periods per revolution"

Is a BiSS encoder compatible with most drives?

Sorry I realize this isn't a Kflop question, just hoping those with more
experience with servos and drives might know if is worth pursuing the
Beckhoff motors.

Thanks

Greg.

You might take a look at Emerson Control Techniques
M700 servo drive.
They are designed to accept a whole slew of feedback
devices. I would suggest contacting application
engineers at the factory. 952-995-8000
They are knowledgeable people.

Good Luck!

AZ