[Dave3891]

I am working on a large 5 axis plasma table that I will need kinematics for beveling with a 5 axis head so I am looking to use a Kflop for this machine.

I was thinking of using brushless servos for the X and Y axis with closed loop control and regular open loop steppers on the Z, A, C axis's.

Will there be any problems doing this with a kflop?


I looked in to using LinuxCNC first and got the kinematics working in simulation, but I didnt really like how difficult it was to make a custom GUI and I just want to use VB.net now since I know it well.


Any info would be appreciated.


Thanks
Dave

[TomKerekes]

Hi Dave,

There should be no problem mixing motor types. It isn't clear what type of amplifiers you are considering. You obviously will need to plan things out so you have the right types of IO available.

We have an improved example Dynomotion VB.Net in our later Test Releases such as :

www.dynomotion.com/Software/KMotion430j.exe

Regards
TK

[Dave3891]

I have been looking through the source code and the VB interface stuff seems pretty simple and straight forward.

But am I right in assuming that I will need to re-compile the gcode interpreter with my custom kinematics for it to work, or am I able to set them with a simple C thread program?


Dave

[TomKerekes]

Hi Dave,

Yes you currently must change and compile the Kinematics.cpp file that is an MFC C++ Class that runs on the PC and is part of the GCodeInterpreter.dll.

I suppose now that you mention it it might not be too hard to make a special Kinematics Class that exports the critical functions as .NET Interop call backs. That way the equations could be written in C# or VB.

Regards

[Dave3891]

If you add that to a class let me know since it will make is alot easier then getting a copy of VC2008 to build the DLL.

I won't be using one of these systems for about a month so I am just looking to make sure it will implement all of the features that I need it too.

With the VB example I see how it loads and runs a file to the interperter, but how can I get the line number that it is on and how can I run it from a mid point in the file? Do I just need to move a pointer with in the file stream?

If this system works out well on the plasma system I might get 2 more and use them to replace galil systems on 10' x 20' 40HP drills since the galil systems are ISA legacy running on DOS. How does the Kflop compare to Galil cards?

One more question,
I read in another post about kflop having modbus coms. Is this ran within a C thread or is it just controlled through a port in the GUI software? I was thinking of adding a automation direct click PLC for more IO and adding it with the modbus.


Thanks
Dave

[TomKerekes]

Hi Dave,

There is a call:

/// <summary>
/// Interpret a File with the functionality to only interpret a portion of the file
/// (useful for resuming execution after a program stoppage)
/// </summary>
/// <param name="fname">Full path of the file to interpret</param>
/// <param name="start">first line to execute</param>
/// <param name="end">Last line to execute</param>
/// <param name="restart">Need Clarification</param>
/// <returns>Error Code</returns>
public int Interpret(string fname, int start, int end, int restart)


The Interpreter generates callbacks to provide status before each line is executed which includes the line number.

The Dynomotion VB.NET example sets up the callbacks with:

' Interpreter Params
AddHandler _Controller.CoordMotion.Interpreter.InterpreterSta tusUpdated, AddressOf InterpreterStatusUpdated
AddHandler _Controller.CoordMotion.Interpreter.InterpreterCom pleted, AddressOf InterpreterComplete


Regarding ModBus: it connects to a UART on KFLOP. The code is in the C Programs/RS232/ModBus directory.

HTH
Regards

[Dave3891]

Thank you.

Can the kflop do dual loop encoder feedback like the galil cards?
On our large machine we have servos with gear boxes and rack/pinion on the X, X1, Y axis and they have linear scales attached as well.
The galil uses both encoders for the PID.


Dave

[TomKerekes]

Hi Dave,

Dual loop is possible but it consumes 2 Axis Channels and you must cascade the loops with a C Program.

The nice thing about it is that you have a full set of Tuning Parameter (PID, Filters, Limits, etc...) for both loops. And you can tune them separately.

We get the question asked a lot but few Users do it that way. It is more common to have the inner loop closed by the Amplifier and then close the outer loop with KFLOP.

It is common to do a dual loop on Z for something like THC or Laser focus.

Regards

[Dave3891]

Would you set the motor amplifier in position mode then and use a pulsed output while monitoring the linear scale?


Dave

[TomKerekes]

Hi Dave,

You should be able to do it either way. Feed Position as Step/Dir into the amplifier or Analog Velocity. I'm not really sure which is the best. I think it can be shown to be mathematically equivalent from a control theory standpoint.

Here is a build Thread from Ryan who documents things beautifully.

http://www.cnczone.com/forums/bencht..._g0704-14.html

Regards