Upgrading 1978 Bridgeport CNC Series I to KFlop - SnapAmp control

Hi Jake,

Another User also discovered that bug but hasn't had time to test our fix. It seems to be triggered by small moves when larger buffering times are specified. Recent test versions have a buffer underflow protection that is designed to reduce feedrate in the unlikely event the buffer becomes critically low. Previous versions allowed the buffer to run empty and starve. This protection needs to be turned off when the buffer is really at the end and it is desired to run empty. A "FlushBuf" command is need to allow KFLOP to do this. We found a special case where the Mach3 Plugin did not do this.

Here is a patched plugin that should fix the hang after a Mach3 "Step". Copy to Mach3 Plugins directory to try.

http://www.dynomotion.com/Software/P...Dynomotion.dll

Please let us know if this solves the problem.

Regards

Hi Tom,

The updated DLL seems to have fixed the problem!

What about soft limits and positive limits? Should they be set in both Dynomotion and Mach3?

Happy day,

Jake

Hi Jake,

Thanks for posting back.

Yes you should probably set the soft limits in Mach3 as well as KFLOP. KFLOP's soft limits will trigger as the Axis moves into the Soft Limit. Mach3 Soft limits may trigger before the motion is even commanded or during verification (I'm not sure).

Regards

Hi Tom,

Issues still exist with mach3 and small moves. It will job 0.001" one time only/ Then the motor just bumps forward and back a tiny bit but no movement. Also does not update DROs in Mach3 to indicate that it thinks it made the move either.

DynoCNC works perfectly like usual!

Thanks,

Jake

Hi Jake,

Looking for clues in KMotion.exe what do you see? Anything printed to the Conole Screen? Does the Axis Screen still show all the axes enabled? Does the Destination Change when you make the move?

Try entering "FlushBuf" in the Console to see if it clears the problem and allows another move.

Regards

,

No good clues from KMOTION except the destination replicates the Mach3 behaviour of moving once and then not updating destination. There is every time an audible bump.
Flushbuf does not help.

A little more data.
Y axis display zeroed in Mach3 and KmotionCNC before each jog move.

Jog 1" mach3 - perfect

Jog 0.1" mach3 - perfect

Jog 0.01" mach3
-Mach3 says move of 0.008
-KmotionCNC says move of 0.0094

Jog 0.01" mach3
-Mach3 says move of 0.008
-KmotionCNC says move of 0.0080

Jog 0.01" mach3
-Mach3 says move of 0.008
-KmotionCNC says move of 0.0080

Jog 0.01" KmotionCNC
-Mach3 says move of 0.012
-KmotionCNC says move of 0.01

Jog 0.01" KmotionCNC
-Mach3 says move of 0.012
-KmotionCNC says move of 0.01

Did not reset DROs
Jog 0.01" KmotionCNC
-Mach3 says move to0.02
-KmotionCNC says move to 0.02
Physical axis readout 0.02

Just noticed Accel was 15 in Mach3 and 20 in KmotionCNC. Both set to 20.

Restart both programs and home.

Jog 0.01" KmotionCNC
-Mach3 says move of 0.008
-KmotionCNC says move of 0.01

Did not reset DROs
Jog 0.01" KmotionCNC
-Mach3 says move to0.02
-KmotionCNC says move to 0.02
Physical axis readout 0.02

Jog 0.01" KmotionCNC
-Mach3 says move of 0.02
-KmotionCNC says move of 0.02
Physical axis readout 0.02
repeat several times. On average they match.

++++++++++++++++++++++++++++++++++++++++++++++
all counters reset
Jogging 0.005"

KmotionCNC Jog
KmotionCNC = 0.005
Mach3=0.004 -lagging

KmotionCNC Jog
KmotionCNC = 0.010
Mach3=0.008 -lagging

KmotionCNC Jog
KmotionCNC = 0.015
Mach3=0.012 -lagging

KmotionCNC Jog
KmotionCNC = 0.02
Mach3=0.02 -Caught up

KmotionCNC Jog
KmotionCNC = 0.025
Mach3=0.024 -lagging

KmotionCNC Jog
KmotionCNC = 0.030
Mach3=0.028 -lagging

KmotionCNC Jog
KmotionCNC = 0.035
Mach3=0.032 - lagging

KmotionCNC Jog
KmotionCNC = 0.040
Mach3=0.040 -Caught up.

REZERO
Mach3 Jog 0.005"
Mach3=0.0040
KmotionCNC=0.0040
Physical=0.0045

Mach3 Jog 0.005"
Mach3=0.0080
KmotionCNC=0.0080
Physical=0.0085

Mach3 Jog 0.005"
Mach3=0.0120
KmotionCNC=0.0120
Physical=0.0130

Mach3 Jog 0.005"
Mach3=0.0160
KmotionCNC=0.0160
Physical=0.0165


===================
Mach3 Jog 0.001"
Mach3=0.0000 made a bump sound
KmotionCNC=0.0000
Physical=0.0000

---
KmotionCNC Jog .001
Mach3 0.000

Repeatedly jog Kmotion CNC 0.001

Kmotion	Mach3
0.001	0.000
0.002	0.004
0.003	0.004
0.004	0.004
0.005	0.004
0.006	0.008
0.007	0.008
0.008	0.008
0.009	0.008

What do you think Tom?

Thanks,

Jake

Hi Jake,

We recently realized that Mach3 treats position readback as integer "steps" rather than floating point units that it doesn't work well operating SnapAmp driving Stepper in units of cycles (invDistPerCycle=1) as we have previously recommended. Its better to use something like 0.001 to provide more resolution for Mach3. See this recent post on the Yahoo Group. Please see if this resolves at least part of your issues.

https://groups.yahoo.com/neo/groups/...messages/11198

Regards

Hi Tom,

This changed produced beautiful results.

Mach3 now will jog to the motor resolution.
I have two original motors from the mid 70s. Along the way I became convinced that my Z motor was troublesome and replaced it with a modern one.. That axis will step reliably now to 0.0001"! The other two with old motors step to 0.001" perfectly.

It may be my imagination but, I think that moves in KmotionCNC are smoother with the new settings too!

I will report if I notice anything else different.
As you come across improvements, I am willing to beta test for you!

Happy day,
Jake

Hi Tom,

Successfully making parts now with this machine!

Already looking to upgrade to do tapping.

It has a 2hp Induction motor currently. I could get a VFD for it. Or I could get a 2hp DC motor and hook it up as a servo.

For the VFDs they seem to want 4-20ma or 0-10V. Some accept RS485 to send direct control commands.
It would seem ideal to send digital information. Why convert thru Analog?

For the DC, typical voltage in this size is 130V or so. Would I need an input supply with this voltage to use on the SnapAmp?

Your thoughts are appreciated.

Happy day,

Jake

Hi Jake,

To do rigid tapping some form of feedback is usually required. It isn't that important that the spindle moves in an exact manner but rather that the spindle position is known in order that KFLOP can synchronize the Z motion to it. The Spindle feedback doesn't necessarily need to go back to KFLOP, but if it doesn't then the VFD must be capable of being told where to be and it must be cable of actually following the commanded position with sufficient accuracy to tap properly. For example some VFDs can be driven with open loop Step/Dir pulses and will track properly as instructed.

Is it possible for you to add encoder feedback for your spindle?

SnapAmp isn't likely to be suitable to drive your Spindle.

Regards

Hi Tom,

So I have revised down my expectations for the time being.

I have close to success using a tapping head now, but have trouble setting my spindle speed very well as the feed back is only the pointer on the crank.
I have put an encoder (512 quadrature output non-differential) on the spindle. I have it hooked into the KFLOP board as the standard encoder3 pins.
I can see the pins flip as I manually turn the spindle.

So how do I get a speed signal out of this?
I have set the input type on CH6 to encoder and set the pin #s correctly.
I have enabled the axis.

In Mach3 I have put the info into the threading sensor window on the plug in config page. Nothing. . .

I just have no output.

:-)

Thanks,

Jake

Hi Jake,

Quote:

---

I have set the input type on CH6 to encoder and set the pin #s correctly.

---

This doesn't sound correct. Which encoder input to use should be specified as InputChan0 not pin numbers. When this is configured correctly The Axis Screen should show Axis 6 Position changing as the spindle turns.

Quote:

---

I have enabled the axis.

---

You probably don't want to enable the axis at this point. The Axis doesn't need to be enabled to monitor encoder position. Eventually you might want to do full closed loop control. But It isn't clear to me if or how you command the spindle motor. You were talking about various ways of control a few posts ago.

HTH
Regards

Hi Tom,

I had it close. I just used axis 4 instead of axis 3 in the threading section of the plugin config!

So now, I have an awesome display of speed.

There is no obvious scaling factor between what I see and what I expect.

The encoder is single ended quadrature output 512 pulses per revolution.
I have put 512 in the Dynomotion plugin config in the threading section.

I have put 512 in for Encoder4 (Enabled, A-Port# 13,0, B-Port#14,0) in Ports&Pins in Mach3 although this seems to not make a difference to output scaling on the "DRO", nor does the Velocity entry as far as I can tell.

I had hoped, to not have to get a strobe to calibrate it. Am I missing something?

Happy day,

Jake

Hi Jake,

KFLOP handles the Encoder input signals not Mach3 so you should remove those Parallel Port Settings although Parallel Ports 13 and 14 probably don't exist so it shouldn't matter. Set them to Port0 Pin 0 as dummy settings.

Not sure what you are asking regarding not needing a strobe. But if you rotate the spindle one revolution the KFLOP Axis Screen Position should change by 512. Or better yet rotate it 10 times and the Posiion should change by 5120 counts. If this is correct and you have 512 entered into Mach3 then the RPM should be accurate.

Regards

Hi Tom,

I have done as suggested. I get good readings now.

Given that my machine is a bridgport, I have a gearbox for low range that is downstream from the encoder.

Is the rpm data separate from the "pulley setup" in Mach3? I wondered if there is a way to tell the system that I am using the Low Range?

Thanks Tom,

Happy day,

Jake

Hi Jake,

I'm not sure exactly what you are asking and I'm not that familiar with Mach3. But I believe by changing the InputGain0 value in the KFLOP Axis for the Spindle Encoder you could correct for the gearing and make the RPM read correctly. But I'm not sure how you would know what gear it is in and when it changed. I think the Mach3 Pulley number is in Mach3 DRO 56. You might have a button or MacroPump executing in Mach3 to set the "Pulley" number into a KFLOP Variable so KFLOP could then change the InputGain0 appropriately.

Regards

Hi Tom,

I put a little routine in the spindle call thread that changes the InputGain. works perfectly even responds dynamically during G-Code speed change!!

Quote:

---

#include "KMotionDef.h"

//Plugin Notifications and defines..
enum { EX_DDA , EX_VMS, EX_COMMAND, EX_SPINON, EX_SPINOFF, EX_SPINSPEED, EX_MOTORTUNED
, EX_SETUP, EX_FEEDHOLD, EX_RUN, EX_ESTOP , EX_CONFIG };

main()
{
int message = persist.UserData[0]; // Mach3 message ID
int Direction = persist.UserData[1]; // Mach3 Spindle Direction
float speed = *(float *)&persist.UserData[2]; // value stored is actually a float
float SpindleSpeed;
SpindleSpeed=speed*4300; /My Constant
switch (message)
{
case EX_SPINSPEED:
if (SpindleSpeed>500)
{
ch3->InputGain0=1;
printf("+Spindle Speed Set to %f High Range\n",SpindleSpeed);
}
else
{
ch3->InputGain0=1/8.3;
printf("-Spindle Speed Set to %f LOW Range\n",SpindleSpeed);
}
break;


case EX_SPINON:
if (Direction==0)
{
printf("Spindle CW ON\n");
}
else if (Direction==1)
{
printf("Spindle CCW ON\n");
}
break;

case EX_SPINOFF:
{
printf("Spindle Stop\n");
}
break;
}
}

---

Hi Jake,

I'm glad that works for you. I'm not usually one to argue with success - but it isn't clear to me why that works. The "speed" passed to KFLOP is a fraction of motor speed. So I was thinking in Low gear Mach3 might command 50% motor speed. And also in Hi gear Mach3 might command 50% motor speed. So the Speed would be 50% in both cases so it would be impossible to determine from the 50% value which gear was in use. Do your gears work somehow differently? Automatically change with motor speed or something?

Regards