Kfop+Kstep loosing steps

[ltran2000]

A short story: been using Mach+smoothstepper for 7 years and never happy with both,
Mach not that reliable, rounding corner,jerky movement,Smoothstepper: disconnect anytime
And this issue never been solved, so I am looking for a replacement for both, bought kfop
a year ago but afraid to use it because I don’t know anything about c language, after reading all posts from “fish4fun” I decided take it out of the drawer and hook it up, my first impression is how smooth my stepper sound, and while it run a gcode I try to open autocad, word, coreldraw and even watch video but never have disconnect issue and it return
to 12 o’clock pos all the time with gecko 203v, have been leave my PC and kflop on for 2 months straight but no disconnect nightmare that I have with SS, so I am so exciting, have to make this wonderful stuff to work. so just bought kstep to simplify hookup, configuration, hope someone can help with kstep loosing steps.
Kflop+kstep
My set-up: kmotion cnc ver.428
- Power supply: 24v-4.5a connect to J1
- Voltage clamp : A installed – B install – C removed (25v)
- Stepper PK266-02A bipolar 1.4a – 5v -current set: L installed, H,M removed
- Isolate jumper both installed, using 5 v from usb
- JR1, J6 no connections
I am using kmotioncnc ver. 428, using c:\kmotion428\cprograms\kstep\InitKStep3Axis.c
I don’t change anything except toolsetup\trajectoryplanner\count-inch from 10,000
To 5,000 because stepper spin too fast and stall, there are no load on all steppers, I put a tape on stepper pole at 12 o’clock position and run a gcode, after finishing it not return 12 o’clock position anymore, I removed kstep and using Gecko 203v , all setup the same and no lost step at all, I can let it runs gcode all day without any loosing step, is there anything that I am missing, please help. I also tried to remove both isolate jumper and hook up 5v to
J6 but get the same problem.

[TomKerekes]

Hi Itran2000,

Could you try increasing the step pulse to 4us with

FPGA(STEP_PULSE_LENGTH_ADD) = 63 + 0x80;

Regards

[ltran2000]

Hi, Tom
where do I add this line to ? I open c:\kmotion428\DSP_KFLOP\KMotionDef.h
and change this line: #define STEP_PULSE_LENGTH_ADD 0x06 to #define STEP_PULSE_LENGTH_ADD 63 + 0x80
is this the correct way ? otherwise can you attach a file so I just copy and replace,
by the way it lost certain amount each time i run a 3 minute gcode, from 12:00 to 12:03 and 12:06 each time,
not randomize, I also tried new power supply 40v-15a, thank for your help.
ltran2000

[TomKerekes]

Hi Itran2000,

No. You would add that exact line of C code into your InitKStep3Axis.c program to the beginning of the main function. Such as:

#include "KMotionDef.h"

// Defines axis 0, 1, 2 as simple step dir TTL outputs for KSTEP
// enables them
// sets them as an xyz coordinate system for GCode

int main()
{
double T0, LastX=0, LastY=0, LastZ=0, Tau;

KStepPresent=TRUE; // enable KSTEP input multiplexing

FPGA(STEP_PULSE_LENGTH_ADD) = 63 + 0x80;

.
.
.

[ltran2000]

Problem solved, thanks Tom for your help, if i can can make this work, everyone can, like i said i don't know anything about C language, this is a very affordable system:
-- klop $250 + kstep $200(4 drives) +free kmotioncnc = $450 plus a super support,
next i will figure out how to hook-up relay output for spindle and home/limit switch and all will be set, I will report back when i have time to hook-up to real router and see how it perform, Thanks Tom

[ltran2000]

I tested some more after adding that line code and no more miss steps,
now how can i slave channel#3 to channel#0 (X axis),
this is how i do it :
--- open kmotion, click on "config&flash"
--- channel=3
--- axis modes, input=no input, output=step dir
--- input channel, 0, gain=1, offset=0
--- outputchannel, 11, gain=1, offset=0
--- master/slave, slave gain=1, master axis=0
--- click on "download channel"
--- click on "c code clipboard"
--- open c:\kmotion428\cprograms\kstep\InitKStep3Axis.c
--- paste the clipboard into "InitKStep3Axis.c" right after
the end of channel 2
--- add "EnableAxisDest(3,0);" at the end of channel 3
is this the correct way to do it ? seem it work for me but just make sure i did it right. Thanks

[TomKerekes]

Yes that sounds correct to me. Homing Slaved axes is usually a bit tricky. Usually the axes are de-slaved, then both homed independently but at the same time while each watching for separate home switches and stopping independently.

Regards

[ltran2000]

Thanks Tom, I just notice that after finishing a job a few seconds kstep
turn-off all axises off completely, it should reduce current when idle but not turning off, because when I change tool bit i may move the gantry, how do i change this, thanks.

[TomKerekes]

The loop at the end of the Init.c program is what does this. Delete the entire loop and it will never disable. If necessary it might be possible to PWM the enable to maintain a reduced current.

Regards

[ltran2000]

I am sorry I don't know how to do this either, can you write a script for
"PWM the enable to maintain a reduced current" and exactly where to add
to, thanks

[TomKerekes]

Itran2000,

Try replacing the forever loop with the attached code (I just hope it doesn't making an annoying noise turning off and on at 2.5KHz).

Otherwise did you try deleting the entire loop?

Regards

[ltran2000]

Yes, I did deleted " for (; // loop forever...." to the end, except the very last line " return 0;" and it no longer turn-off any more, I also added the "PWM enable", my steppers are not making any noise at all. Thanks