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Author Topic: Rigid tapping with IP-A  (Read 24226 times)

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Offline Hood

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Re: Rigid tapping with IP-A
« Reply #30 on: May 19, 2013, 07:21:52 PM »
It has been possible to do rigid tapping for a lot longer than that Sam, as long as you had a servo or stepper on the spindle, no other hardware required. Was it a good way, well not really, you had to use swapaxis() and to be honest I just used the floating holder as it was easier and did a great job.

Regarding tuning in one place, well its all done in Mach, the plugin is in Mach ;)
I presume you have to tune your spindle loop in LinuxCNC?

Now did I need to use the PLC, nope, CSMIO has a load of I/O and lots of expansion capability if required. So why did I use a PLC, well two reasons,
1. I had one sitting doing nothing.
2  I know my way around the direct logic PLCs so its easy. Doing it in Brains and/or VB would take me longer, but it could be done and has been by others.
 
The ladder in my PLC runs to, I think, 17 pages of A4 when  printed out at 60%, lots of I/O on this changer and I wanted lots of interlocks, you can even see one working in one of the vids. The toolchange takes a lot longer to happen simply because I had such a slow accel/decel set for the test and the spindle took so long to drop to 200rpm which is the tool change rpm and the toolchange will not happen until that rpm is seen.

Even if in the future if I decide to go with LinuxCNC (about as likely as you using Mach,  but never say never ;) ) then I would still use the PLC, for the simple reason I would not have to learn the ladder logic in Linux. That is assuming LinuxCNC supports Modbus?

One thing I really like about the CSMIO is the capability of using high res encoders, that means very tight control can be kept.


Hood
Re: Rigid tapping with IP-A
« Reply #31 on: May 20, 2013, 09:40:48 AM »
Sure - stepper/servo spindle as an axis - sure.  That has been possible on both platforms for a long time.  (I don't think it is a good way either...)

I did not know the plug-in within mach allowed for pid tuning and such - neat.  I don't know what you mean by tuning the spindle in linuxcnc.  Yes - if the spindle has its own pid loop for speed control - you would tune it within linuxcnc.  Some do that.  The vfd on our hmc does good enough that I never setup closed loop speed control.  It isn't required for rigid tapping as the axis is slaved to the spindle.  The axis just stays in sync with whatever the spindle does.  (don't know if that is what you where asking..)

I don't know how standard the plc language is in linuxcnc.  I didn't have any trouble wrapping my head around it - having only some exposure in college...  I am about 50/50..  I did the tool change/chain/pallets logic in ladder and the spindle gear shift logic in 'comp'  (a C like language for making realtime components in linuxcnc) I could wrap my had around the 16 gear spindle programmatically vs ladder.  Again - vs the brains/vb - that isn't realtime.  it happens when it happens.  In linuxcnc I know that the ladder is going to scan every 1ms and the realtime logic is going to happen every X ms or us..  

There is modbus support - but I cannot give you any details as I have never used it.  I mostly see people using it to interface with their vfd's

I hear you with switching.. I don't think I would either.  I like the control that have with linuxcnc.

with mesa hardware (5i25 with server daughter board - 6 axis + 48i/o + expandable $239) you can count to 2mhz.  

Again - awesome conversion.

sam



It has been possible to do rigid tapping for a lot longer than that Sam, as long as you had a servo or stepper on the spindle, no other hardware required. Was it a good way, well not really, you had to use swapaxis() and to be honest I just used the floating holder as it was easier and did a great job.

Regarding tuning in one place, well its all done in Mach, the plugin is in Mach ;)
I presume you have to tune your spindle loop in LinuxCNC?

Now did I need to use the PLC, nope, CSMIO has a load of I/O and lots of expansion capability if required. So why did I use a PLC, well two reasons,
1. I had one sitting doing nothing.
2  I know my way around the direct logic PLCs so its easy. Doing it in Brains and/or VB would take me longer, but it could be done and has been by others.
 
The ladder in my PLC runs to, I think, 17 pages of A4 when  printed out at 60%, lots of I/O on this changer and I wanted lots of interlocks, you can even see one working in one of the vids. The toolchange takes a lot longer to happen simply because I had such a slow accel/decel set for the test and the spindle took so long to drop to 200rpm which is the tool change rpm and the toolchange will not happen until that rpm is seen.

Even if in the future if I decide to go with LinuxCNC (about as likely as you using Mach,  but never say never ;) ) then I would still use the PLC, for the simple reason I would not have to learn the ladder logic in Linux. That is assuming LinuxCNC supports Modbus?

One thing I really like about the CSMIO is the capability of using high res encoders, that means very tight control can be kept.


Hood

Offline Hood

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Re: Rigid tapping with IP-A
« Reply #32 on: May 21, 2013, 06:47:17 AM »

I did not know the plug-in within mach allowed for pid tuning and such - neat.

Yes often the case when trying to score points ;) should really research before you do, that is why I dont criticise EMC as I know very little about it  ;)

Quote
I don't know what you mean by tuning the spindle in linuxcnc.  Yes - if the spindle has its own pid loop for speed control - you would tune it within linuxcnc.  Some do that.  The vfd on our hmc does good enough that I never setup closed loop speed control.  It isn't required for rigid tapping as the axis is slaved to the spindle.  The axis just stays in sync with whatever the spindle does.  (don't know if that is what you where asking..)

Well it was really just because you were saying I had to tune my spindle and it sounded like EMC magically could mind read your VFD so tuning was not required ;D But I see now the main thrust of your argument was tuning in different place from other set-up but that is now known by you to be wrong ;D
 
 Yes tuning is not important for rigid tapping, however precise depth control then becomes trial and error, something I am sure you would soon fall into with use on your particular machine at particular spindle speeds in a particular material etc, ie just try,  measure then increase/decrease in the code to suit.

Quote
I don't know how standard the plc language is in linuxcnc.  I didn't have any trouble wrapping my head around it - having only some exposure in college...  I am about 50/50..  I did the tool change/chain/pallets logic in ladder and the spindle gear shift logic in 'comp'  (a C like language for making realtime components in linuxcnc) I could wrap my had around the 16 gear spindle programmatically vs ladder.  Again - vs the brains/vb - that isn't realtime.  it happens when it happens.  In linuxcnc I know that the ladder is going to scan every 1ms and the realtime logic is going to happen every X ms or us.. 

Here you go again, real time, is it needed for a tool change? I think not. Brains are extremely fast but constrained by Mach3's update of 10Hz for non-critical I/O but if 10Hz is not fast enough for your toolchanger then I would be very surprised. And as far as "it happens when it happens" well no, it happens within the expected time frame.

Mach4's update will be much faster but Brains wont be in Mach4 ;)



Quote
with mesa hardware (5i25 with server daughter board - 6 axis + 48i/o + expandable $239) you can count to 2mhz. 

Ahh come on now Sam, thats only half your war cry, tell me again, I seem to have forgotten, how much does LinuxCNC cost? ;)
2MHz is quite good, especially for hardware at that pricepoint.


Now I do need to say one thing Sam, I do respect what you have done with your machine but more importantly I respect your integrity. I recall some guy listening to John S babbling on how Mach4 wont have threading with the PP etc, so he went to Yahoo and asked Art directly, again trying to get the info he wanted to hear so he could score points.
 Art replied but it was not the info he wanted to hear. The guy  never posted the info from Arts reply on the homeshop  forum as it would not be possible to score points.
  You however reported that info and  my respect for you went up considerably :) You did still manage to get a wee dig in though ;) but that is why I enjoy this banter.
Hood
Re: Rigid tapping with IP-A
« Reply #33 on: May 21, 2013, 09:17:30 AM »
Yes - hitting the bottom of a hole is defiantly a pain.  Our spindle mass is huge so acc/decel are long.  (that is one thing A axis servo spindle tapping has over this :) ) Commercial machines that actually do servo spindle tapping call it 'sync tapping'  iirc

I don't have blinders on (too much) I try to be fair as much as I can be ;)  (I still think linuxcnc is the bestest of course. )

You have been 'one' with mach and have made it do thing I never thought it could.  (with help from external motion devices <- I am a bitch - I know...) ;)  I see you always going above and beyond to help people with their setups.   'send me your xml and I will take a look'  We need more experts on both sides to keep pushing the envelope.

Now back to your rigid tapping thread.  You did a great job on a very very technical conversion.  Keep up the great work!

sam



I did not know the plug-in within mach allowed for pid tuning and such - neat.

Yes often the case when trying to score points ;) should really research before you do, that is why I dont criticise EMC as I know very little about it  ;)

Quote
I don't know what you mean by tuning the spindle in linuxcnc.  Yes - if the spindle has its own pid loop for speed control - you would tune it within linuxcnc.  Some do that.  The vfd on our hmc does good enough that I never setup closed loop speed control.  It isn't required for rigid tapping as the axis is slaved to the spindle.  The axis just stays in sync with whatever the spindle does.  (don't know if that is what you where asking..)

Well it was really just because you were saying I had to tune my spindle and it sounded like EMC magically could mind read your VFD so tuning was not required ;D But I see now the main thrust of your argument was tuning in different place from other set-up but that is now known by you to be wrong ;D
 
 Yes tuning is not important for rigid tapping, however precise depth control then becomes trial and error, something I am sure you would soon fall into with use on your particular machine at particular spindle speeds in a particular material etc, ie just try,  measure then increase/decrease in the code to suit.

Quote
I don't know how standard the plc language is in linuxcnc.  I didn't have any trouble wrapping my head around it - having only some exposure in college...  I am about 50/50..  I did the tool change/chain/pallets logic in ladder and the spindle gear shift logic in 'comp'  (a C like language for making realtime components in linuxcnc) I could wrap my had around the 16 gear spindle programmatically vs ladder.  Again - vs the brains/vb - that isn't realtime.  it happens when it happens.  In linuxcnc I know that the ladder is going to scan every 1ms and the realtime logic is going to happen every X ms or us.. 

Here you go again, real time, is it needed for a tool change? I think not. Brains are extremely fast but constrained by Mach3's update of 10Hz for non-critical I/O but if 10Hz is not fast enough for your toolchanger then I would be very surprised. And as far as "it happens when it happens" well no, it happens within the expected time frame.

Mach4's update will be much faster but Brains wont be in Mach4 ;)



Quote
with mesa hardware (5i25 with server daughter board - 6 axis + 48i/o + expandable $239) you can count to 2mhz. 

Ahh come on now Sam, thats only half your war cry, tell me again, I seem to have forgotten, how much does LinuxCNC cost? ;)
2MHz is quite good, especially for hardware at that pricepoint.


Now I do need to say one thing Sam, I do respect what you have done with your machine but more importantly I respect your integrity. I recall some guy listening to John S babbling on how Mach4 wont have threading with the PP etc, so he went to Yahoo and asked Art directly, again trying to get the info he wanted to hear so he could score points.
 Art replied but it was not the info he wanted to hear. The guy  never posted the info from Arts reply on the homeshop  forum as it would not be possible to score points.
  You however reported that info and  my respect for you went up considerably :) You did still manage to get a wee dig in though ;) but that is why I enjoy this banter.
Hood

Offline Hood

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Re: Rigid tapping with IP-A
« Reply #34 on: May 21, 2013, 09:47:10 AM »
Sam can you not tune your VFD in Linux?  I am sure you can but maybe just not bothered?
With the CSMIO I could use a VFD and still tune it so that precise depth is possible but never had to as dont use VFDs.


Regarding the Chiron, not really that hard, just have to sit down and think about things and think of ways to do what you need.
Your Kearney would just have been the same I imagine, in fact any machine is that way, just a matter of scale of problems to solve..
Hood

Re: Rigid tapping with IP-A
« Reply #35 on: May 23, 2013, 12:11:14 PM »
...those snooty LinuxCNC guys. ;)
You guys know that was a joke right?  I have the utmost respect and admiration for everyone from both the Linux & Mach camps.

Moreso on the Mach side 'cuz they patiently & kindly train me on an almost daily basis.

After perusing the Linux forum, I'm sure I'd get great support there too if this ol' dog wanted to learn new tricks.

Did I get that right Sam...just like you told me?;)
Milton from Tennessee ya'll.

Offline Leeway

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Re: Rigid tapping with IP-A
« Reply #36 on: May 24, 2013, 05:55:49 PM »
Great thread, Guys. Nice machine too, Hood.
I recently received a Novakon Torus. It can do rigid tapping too and I have been working with John at Novakon on it.
Sheetcam outputs nice rigid tapping gcode, but when I try it in standard Mach, once at the bottom of the tap, the spindle starts a few thousandths of a second before the Z starts lifting. That is a crying shame.

This machine has a servo spindle and it has a switch on the BOB.
You don't have to flip the switch each time, but I keep it switched to tapping.
It still does all other milling and drilling well too.
That switch makes it like the spindle is the A axis I think and then A and Z are synced with some code snippets that are adjustable.

I have it all working on my first test tapping run now except that I cannot get it to stop in between the drilling cycle and the tapping cycle. Mach stops at tool change fine earlier in.
Is there a code snippet I can use to force Mach to stop and stay at the tool change position?

I'll post some video when I get it doing right.
Thanks in advance.
Lee

Offline Leeway

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Re: Rigid tapping with IP-A
« Reply #37 on: May 24, 2013, 06:10:16 PM »
Here is a code snippet, BTW.

I have different tool numbers, so Mach should stop. I have it set that way in the general settings.



N1980 (Operation: Drill, SPRING_HOLE, T12: Drill, 0.0938 in diameter, 0.28 in Deep)
N1990 S500 G00 Z0.1000
N2000 M09 (Coolant off)
N2010 M05
N2020 Z3.5000
N2030 (Drill, 0.0938 in diameter)
N2040 T12 M06  G43 H12
N2050 M08 (Flood coolant on)
N2060 S500 M03
N2070 G00 X-0.4675 Y-0.4661 Z0.1000
N2080 Z0.0197
N2090 G01 Z-0.070 F3.0
N2100 G00 Z0.1000
N2110 Z-0.0503
N2120 G01 Z-0.140
N2130 G00 Z0.0700
N2140 Z-0.1203
N2150 G01 Z-0.210
N2160 G00 Z0.0000
N2170 Z-0.1903
N2180 G01 Z-0.280
N2190 G00 Z0.1000

N2510 (Operation: Tap, TAP_1, T11: Rigid tap, 0.167 in x 32 TPI, 0.5 in Deep)
N2520 S150 G00 Z0.1000
N2530 M09 (Coolant off)
N2540 M05
N2545 Z3.5000
N2550 (Rigid tap, 0.167 in x 32 TPI)

N2610 G00 X-0.2027 Y-0.7467 Z0.1000
N2615 Z0.0394

M98 P10000
Z.5




This is the code at the end of the program.



O10000          ( S/R Tap 32TPI .5" Deep  )
M49
F 200      ( Arbitrary Feed Rate USE F200 )
G91            ( Switch to Incremental Mode )
G1  Z-0.5 A16   ( Plunge  1/2", Rotate Spindle 16 Times CW )     
G1  Z 0.5 A-16  ( Retract 1/2", Rotate Spindle 16 Times CCW )     
G0  Z 0.1   ( Raise Spindle 0.1" )
G90
M48
M99            ( End Subroutine )
%
« Last Edit: May 24, 2013, 06:16:49 PM by Leeway »
Lee

Offline Hood

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Re: Rigid tapping with IP-A
« Reply #38 on: May 25, 2013, 02:53:58 AM »
It sounds like you may have something similar to Simpsons external SwapAxis controller, in fact it may  even be it as I know he did have some companies interested in it.
Why it will not stop at the toolchange I am unsure, it could be the version of Mach you are using or it could be because of the macro or plugin required for your external swapaxis controller.
I would really need to see documentation on it to see exactly what it is and what it does.
Hood

Offline Leeway

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Re: Rigid tapping with IP-A
« Reply #39 on: May 25, 2013, 07:37:58 AM »
I'm not sure what it is.
The manuals are not ready for these machines yet. I don't recall what the labeling on the BOB said if anything.
I do have a picture I think, but not that great.
The switch is the little black slider in the lower left.

Lee