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Messages - Mike VT

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11
General Mach Discussion / Re: Haas VF1 Conversion
« on: August 18, 2016, 06:46:50 PM »
Thats atleast a start.  Pressing a Stop at anytime just kills everything and sets the gcode program to first line.  So, in my example, I am not pressing Stop after a Feed/hold.  If I do, it just resets the entire program. 

So, I guess I should revert to an ealier version and find out whats wrong over there....

I get it.  So goes the worm.  As you eat, you dig deeper.  (I just made that up, its pretty good I think)

12
General Mach Discussion / Re: Haas VF1 Conversion
« on: August 18, 2016, 06:03:26 PM »
Or, I'm open to Mach 4.  Lot of time in this and right at the end.  Putting all guards back on tomorrow and in theory start running a bunch of parts next week.
Little nervous that I make a stupid mistake when choosing how to control this VMC based on my experience with a simple 2 axis knee mill.

I get that I may have to operate the machine differently than I'm used to.  But what I'm seeing here is that if I need to "Pause" the gcode program, I have no choice but to start the program from the beginning or Stop It and do Run From Here (always confusing).  Thats a hard pill to swallow on very large programs and if true will leave machining marks in the part making them un-acceptable for delivery to customer.

13
General Mach Discussion / Re: Haas VF1 Conversion
« on: August 18, 2016, 03:26:57 PM »
Got a bunch of issues with FEEDHOLD.

So I added a Stop, Cycle/Start and FeedHold switch to my panel.  Started playing around with these to insure they work.

First, issue-  Feed Hold is ineffective at quickly stopping the feed.  Read up on the forum and sure enough, it's gonna keep right on rolling until the buffer on CSLabs is finished.  Actually, it seems more like its going to just coast to a stop some time in the future.  But let me finish.

I started to mess around with 3 different Mach 3 Installations.

Mach 3 On Desktop that nothing has been really confirgured at all.  Not on any machine.
If you run a program, hit FeedHold, it shows a delay and pretends to stop at the point that it coast to a stop.  Press start, it pretends to continue on from that point.

Mach 3 on an actual Knee Mill using an actual parrallel port.
If you run a program, hit FeedHold, it has a significant delay before coming to a stop.  Press Start and it backs up to the last known point which is the last line in the G-Code program.  Works Okay as long as an arc wasn't being executed when you hit the feedhold.

Mach 3 on the Haas using an external motion controller (cslabs)
If you run a program, hit feedhold, it has a "very" significant delay before coming to a stop.  Press Start and it goes to the next point in the G-Code file.  Thats a straight line tool path right across the part.

I get a feeling I already know the answers to my questions but would like to hear it.  My guess, in desktop mode, works like a champ.  On actual machine with parallel port, a semi fix was added to back up and hope for best.  On an external controller, all is lost because there is no "packet control" on what was sent, received and whats remaining.


I have been searching this topic and am quite surprised it has not been more vocal.  The cycle/Start and Feed/Hold are the most used hard switches on a VMC.  Admitteldy, I have had Mach 3 on my knee mill for 3+ years and never really paid attention to this.  On the VMC, its different because I have a Z that is very fast and I have a bunch of different tools with different tool lengths.  Number one thing I use the Feed/Hold for is Z moves on the first run.  I like to hit it just short of contact and do a quick check on the distance to go.  Saves a lot of unexpected (operator/programmer error) crashes and lets you do the first run with moderately fast moves.  Thats not going to happen on the way it works now.  Actually, the way it works now seems to completely make the Feed/Hold about as dangerous as it gets.  Unresponsive and unpredictable.


Really hoping someone has insight.  Have seen suggestions to use older version of Mach.  I'm open to that but would also like to have a clue of what issues I will be facing right out the gate.



14
General Mach Discussion / Re: Normally Open VS Normally Closed
« on: August 13, 2016, 09:24:08 PM »
The asians got this one wrong.  As I stated earlier in this post, safety requires forward thinking.  If a wire gets cut- we should predict the state.  No sane person won't understand that a wire that got cut will very likely go to ground or be cut clean......  It could short to another hot wire but the odds are stacked way against that.

So, when the asian drive folks opt for grounding the input to make it run, they clearly haven't progressed through the lawsuits.

Most PLC's can do the bank of X number of inputs or outputs.  For example, Inputs 0-3 may share the same "common" (not to be confused with DC Com).  If you connect the DC Common to this terminal, this provides a path to ground or specifically DC Common.  So if 24 VDC shows up on any one of 0-3, it will allow current to flow to the "common" terminal because you connected DC Common or ground to that terminal. Howerver, if you hook up 24vdc to the common terminal.  In that case, when you apply 24 vdc to one of those inputs (0-3), no current will flow because 24vdc is on both sides of the circuit.  The Input will not be activated.  In the same setup (24 on the common),  If you ground or connect dcComm to one of the inputs, current will flow "backwards" (thats highly debatable) and the input will register.

It is very useful to have banks of inputs that are selectable for sinking or sourcing.  Case in point is the Automation direct drive I have.  It will only provide a sinking output (meaning it provides a DC Common when ON).  The only way to use this directly is connect 24vdc to my "common" for some input and let the drive provide a ground or DC Common.  This will activate the input.  This is why CSLabs has all those dedicated connections for each input.  If, Like PLC manufactures generally do, they banked 4 at a time, I would waste 4 inputs if only one of my inputs required a sourcing input (meaning current needs to flow out of the input- to the drive------highly debatable again).




15
General Mach Discussion / Re: Normally Open VS Normally Closed
« on: August 13, 2016, 09:19:54 PM »
Wow..l Sound like an old dude.  Kinda sux.

16
General Mach Discussion / Re: Normally Open VS Normally Closed
« on: August 13, 2016, 09:11:12 PM »
To simplify the safety issue.

Imagine standing in front of your machine.  Floor is wet, you happen to be barefooted today with bud lite in your left hand.  You reach out and turn a simple switch to make something go.

Switch is an old/current barrel type swicth that is really a fwd/rev switch that is wired 3 phase 480 volt.  Your spilled bud lite has grounded your bare feet.  That high voltage is 1 inch behind the aluminum face plate you made.  But, your spilled beer has bonded you (like it or not) and there is actually a clean path from the barrell switch contacts to ground through you fingers and bare feet.  NOT GOOD.

So, many years ago, it was figured out that it is much safer to remove high potential voltages from operators.  Two things happened and two thought paths occurred.

Lets only have the neutral or ground (most neutrals are grounded) on the switch panels.  Sounds great.  If you are standing in water and touch a switch that can only provide ground, no current can flow.  Perfect.
Except that, now when wires get damaged, the likely hood is they go to ground and activate the signal. Not so perfect.

The other thought (And I agree with this one) is to minimize the voltage potential at the operator switch.  At first, 120VAC was good enough.  Now we want lower voltages and DC would be good.  So, 24vdc is the standard.  It is really hard to die (or even notice) while touching a switch that is powered by 24vdc with an appropriate circuit breaker (don't forget that one).

17
General Mach Discussion / Re: Normally Open VS Normally Closed
« on: August 13, 2016, 08:45:59 PM »
The asians got this one wrong.  As I stated earlier in this post, safety requires forward thinking.  If a wire gets cut- we should predict the state.  No sane person won't understand that a wire that got cut will very likely go to ground or be cut clean......  It could short to another hot wire but the odds are stacked way against that.

So, when the asian drive folks opt for grounding the input to make it run, they clearly haven't progressed through the lawsuits.

Most PLC's can do the bank of X number of inputs or outputs.  For example, Inputs 0-3 may share the same "common" (not to be confused with DC Com).  If you connect the DC Common to this terminal, this provides a path to ground or specifically DC Common.  So if 24 VDC shows up on any one of 0-3, it will allow current to flow to the "common" terminal because you connected DC Common or ground to that terminal. Howerver, if you hook up 24vdc to the common terminal.  In that case, when you apply 24 vdc to one of those inputs (0-3), no current will flow because 24vdc is on both sides of the circuit.  The Input will not be activated.  In the same setup (24 on the common),  If you ground or connect dcComm to one of the inputs, current will flow "backwards" (thats highly debatable) and the input will register.

It is very useful to have banks of inputs that are selectable for sinking or sourcing.  Case in point is the Automation direct drive I have.  It will only provide a sinking output (meaning it provides a DC Common when ON).  The only way to use this directly is connect 24vdc to my "common" for some output and let the drive provide a ground or DC Common.  This will activate the input.  This is why CSLabs has all those dedicated connections for each input.  If, Like PLC manufactures generally do, they banked 4 at a time, I would waste 4 inputs if only one of my inputs required a sourcing input (meaning current needs to flow out of the input- to the drive------highly debatable again).



18
General Mach Discussion / Re: Normally Open VS Normally Closed
« on: August 13, 2016, 07:55:40 PM »
Agreed,
I used an Automation Direct drive on this conversion (can't beat the price).  Their documentation on Sinking and Sourcing outputs is dead wrong.  And they only did the one I didn't want to use (sinking output).


Off topic,  Never use sourcing inputs on a drive.  Meaning you connect their drive input signal to ground to make it go.  If a wire gets shorted to ground, off goes that drive.  Maybe that is right back on original topic.

19
General Mach Discussion / Re: Normally Open VS Normally Closed
« on: August 13, 2016, 06:48:03 PM »
I get that.  My Message "Coolant works"  was just a quick troubleshooting "catch".  It worked.  I caught a weird Mach situation, posted to forum, got a response about M7,8 and 9 being "real odd ball".  Worked perfectly.

Theres almost always a work around.  I get that.  One brand has this interface.  Try it.  If what you are trying to do doesn't work, just try it another way.  Every major league brand out there has their issues.  Everyone one of them.

Thats the way it works in any multivendor system.  Documentation is what sets them apart.  And I hate documentation.  Most undervalued "cost of doing business" in my world.  It takes forever and is never done.

20
General Mach Discussion / Re: Normally Open VS Normally Closed
« on: August 13, 2016, 06:17:26 PM »
So basically, as often happens, my last 4 or 5 post are crap.  I was testing the M8 function and jumped to a bunch of conclusions.  Thought I would roll on and outsmart the creators.  But turns out if you want M7,8, and 9, you will configure them in Mach Ports and Pins and live with their functionality.  If And But Else, you will write your gcode to use a custom M??? command that's not standard if you don't like it.
Tis What Tis

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