I'm interested in adding some threading capabilities as to my CNC code
with the KFlop without using KMotionCNC. I've only performed manual
threading at this point with no computer control.

I'm familiar with Mach3 using a tach pulse to get the RPM and therefore
calculate the rate at which to move the tooling. I'm trying to better
understand the process and then determine if I can recreate it using the
KFlop and my vb.net code.

In principle this seems simple--determine the RPM of the spindle,
calculate the move and begin. But, knowing that the RPM will slow as
cutting begins and possible vary throughout, it seems as though the IPM
of the cutter must be constantly recalculated, almost every revolution,
in order for the threading to be accurate. Am I correct in assuming
this? If so, it doesn't seem like the type of thing that could smoothly
be executed from dotnet code....almost that it would need to be
performed from within KFlop C code to avoid any type of cogging during
the cuts. I'm thinking this could cause the "chunks" of
"ReadRPM/CutSeveralThreads/Repeat" cycles to have gaps or steps between
them in the threads.

Any suggestions anyone has are greatly appreciated.


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

248 548 2500 w
248 910 3344 c

ringsidecreative.com

<http://ringsidecreative.com/>

Hi Sam,

I'm not sure what you are asking.  Are you referring to single point threading as on a lathe?

Mach3 has a lathe mode that works very well with KFLOP.

Basically the coordinated motion is slaved to the spindle motion.  G32 is used to do this type of motion.  This is performed in real time by KFLOP.  VB on the PC can instruct KFLOP on how to Thread but it can't do the calculations and adjustments itself as the PC doesn't have real-time response.

It does require a quadrature encoder on the spindle.  Or if not an encoder some sort of slotted disk that can generate quadrature signals to determine speed and direction.

Regards

TK

 

I'm interested in adding some threading capabilities as to my CNC code
with the KFlop without using KMotionCNC. I've only performed manual
threading at this point with no computer control.

I'm familiar with Mach3 using a tach pulse to get the RPM and therefore
calculate the rate at which to move the tooling. I'm trying to better
understand the process and then determine if I can recreate it using the
KFlop and my vb.net code.

In principle this seems simple--determine the RPM of the spindle,
calculate the move and begin. But, knowing that the RPM will slow as
cutting begins and possible vary throughout, it seems as though the IPM
of the cutter must be constantly recalculated, almost every revolution,
in order for the threading to be accurate. Am I correct in assuming
this? If so, it doesn't seem like the type of thing that could smoothly
be executed from dotnet code....almost that it would need to be
performed from within KFlop C code to avoid any type of cogging during
the cuts. I'm thinking this could cause the "chunks" of
"ReadRPM/CutSeveralThreads/Repeat" cycles to have gaps or steps between
them in the threads.

Any suggestions anyone has are greatly appreciated.

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

248 548 2500 w
248 910 3344 c

ringsidecreative.com

<http://ringsidecreative.com/>

 

Hi Sam,

I'm not sure what you are asking.  Are you referring to single point threading as on a lathe?

Yes, sorry, I should have been more specific.

Mach3 has a lathe mode that works very well with KFLOP.

Basically the coordinated motion is slaved to the spindle motion.  G32 is used to do this type of motion.  This is performed in real time by KFLOP.  VB on the PC can instruct KFLOP on how to Thread but it can't do the calculations and adjustments itself as the PC doesn't have real-time response.

It does require a quadrature encoder on the spindle.  Or if not an encoder some sort of slotted disk that can generate quadrature signals to determine speed and direction.

That was one of my concerns--that using vb.net might "hiccup" along the move.
Without using Mach3, could I use an index pulse from my lathe, fed to a KFlop input, to do something similiar? Or would it require an encoder/quadrature setup?

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

248 548 2500 w
248 910 3344 c

ringsidecreative.com

Hi Sam,

It doesn't matter whether you are using Mach3 or KMotionCNC KFLOP expects encoder feedback from the Spindle.

You could write a KFLOP User Program to monitor the index pulse and simulate an encoder signal.  I'm not sure how well it would work.  It would depend on how quickly the Spindle speed changes and your Thread accuracy requirements.  The problem with a single pulse is that it takes a whole revolution to detect a speed change and then that error has to be corrected over some period of time.

Regards

TK

 

On 2/14/2017 1:06 PM, Tom Kerekes tk@... [DynoMotion] wrote:

 

Hi Sam,

I'm not sure what you are asking.  Are you referring to single point threading as on a lathe?

Yes, sorry, I should have been more specific.

Mach3 has a lathe mode that works very well with KFLOP.

Basically the coordinated motion is slaved to the spindle motion.  G32 is used to do this type of motion.  This is performed in real time by KFLOP.  VB on the PC can instruct KFLOP on how to Thread but it can't do the calculations and adjustments itself as the PC doesn't have real-time response.

It does require a quadrature encoder on the spindle.  Or if not an encoder some sort of slotted disk that can generate quadrature signals to determine speed and direction.

That was one of my concerns--that using vb.net might "hiccup" along the move.
Without using Mach3, could I use an index pulse from my lathe, fed to a KFlop input, to do something similiar? Or would it require an encoder/quadrature setup?

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

248 548 2500 w
248 910 3344 c

ringsidecreative.com