Messages

6841

Show"N"Tell ( Your Machines) / Re: Success! Mini Machining Center under Mach3 control - Video link

« on: May 01, 2010, 12:32:34 PM »

NOW the big Question(;-)

If you have that much error using the macro with the delay that the macro creates, what will the error be without the delay from the macro???

"THAT" was where I ran into trouble(;-) I guesss it will depend on how much following error "your" drive allows before it errors out(;-)

6842

VB and the development of wizards / Re: limits on off in vb code

« on: May 01, 2010, 09:22:15 AM »

Just out of curiousity WHY would you want to move beyond a limit switch to do a tool change. Limits are normally at the outer most travel of your machine to protect the machine and every thing takes place inside that envelope.

6843

Show"N"Tell ( Your Machines) / Re: Success! Mini Machining Center under Mach3 control - Video link

« on: April 30, 2010, 07:34:30 PM »

Is that running with the macro to lock/unlock ? Using the macro it is a sure thing no problem

TO be seamless you have to eliminate the macro right?

6844

Show"N"Tell ( Your Machines) / Re: Success! Mini Machining Center under Mach3 control - Video link

« on: April 30, 2010, 10:19:38 AM »

actually the 4th axis was a rotary the steps per inch was a slip.  The Tormach approach uses a lath  BUT it also has a rotary axis hookup that has a quick attachment to convert it to an indexer/interpolated 4th.

Their setup requires manual setup to convert but it only takes about 10secs or so to convert it.

IF you are providing the drive then this is a moot point as you can get the drive setup with a configuralble buffer system that wil wait on the brake. BUT you will have to be able to turn the function off IF you want to do interpolated 3d work.

I think most users are going to want it to do both functions once they start using the 4th(;-) it is like Crack once you get the 4th YA CAN"T LIVE WITHOUT IT. (;-)

6845

VB and the development of wizards / Re: limits on off in vb code

« on: April 29, 2010, 09:14:29 PM »

While you cannot turn the switches on and off you can use a relay to shunt across the circuit so they are not seen by mach as tripped(;-)

6846

Show"N"Tell ( Your Machines) / Re: Success! Mini Machining Center under Mach3 control - Video link

« on: April 29, 2010, 08:24:18 PM »

"THE "problem we ran into was that the servo BRAKE as fast as it is was way too slow in releasing the brake to prevent the servo from erroring on position error.The next moves were already at the drive BEFORE the brake could react. You have to be able to regulate that data stream of pulses to alow time for the brake to react BEFORE it gets the next move command. That fact that we had high resolution servos that require high step feedrates may have contributed to the problem 45000 steps per inch.

At full speeds that is not a lot of time in between pulses to activate the brake(;-)

Now sometimes it would work fine depending on the code and other times it would error depending on the code. TO me if it cannot operate 100% of the time it is a bust.

OF course IF you used a special buffered input servo drive THEN it may work on simple A axis "non interpolated" moves as the drive MIGHT be able to buffer the data stream enought to allow the brake time to release before it errors on position.

BUT THEN you have created a unique realtime mini drive system that the average user does not have. (;-)

Like I said earlier it  worked  fine in a reatime enviroment as the controller (PCcontroller or motion card) can regulate the closed loop data stream.


BUT hey maybe you have figured out a better mouse trap, GO FOR IT and let us know how it goes.

By the way good job on the 4th axis setup. Have you looked at the system that TORMACH uses with their 4th axis indexer/lathe set?

6847

Show"N"Tell ( Your Machines) / Re: Success! Mini Machining Center under Mach3 control - Video link

« on: April 29, 2010, 01:44:44 PM »

Doing it at the servo drive level won't work either, Tried that as well using the servo brake

Anything you see at the drive level is already BEHIND the time curve of the buffered data AND mach has no idea what is happening at the servo level movement wise so it cannot STOP the data flow out of the port.

6848

Show"N"Tell ( Your Machines) / Re: Success! Mini Machining Center under Mach3 control - Video link

« on: April 29, 2010, 11:45:18 AM »

Current Hi/low is an ouput signal that can be mapped to pin/port, look in config,pin/port,output.  BUT it signals on ANY axis movement and is WAY too far behind the data stream time wise.

I have seen this done from a motion card and a realtime system. I cannot fathom it working from mach(;-( WITHOUT the use of a macro. You would have to be able to TAP the function into the DRIVER level. AND as Art said once "That aint gonna happen".

BUT I will keep the thinking cap running(;-)

6849

Show"N"Tell ( Your Machines) / Re: Success! Mini Machining Center under Mach3 control - Video link

« on: April 29, 2010, 10:35:53 AM »

I see 2 problems to overcome.

1. Mach is a buffered system all moves are planned adn then sent to the buffer for output. Once in the buffer there is little interaction back to mach as to when a Aaxis move is being sent out.

2. Latency of the mechnanism. You will need to be able to "start" to deactivate the brake long BEFORE mach makes the actual move.

There is a signal mach has "current hi/low" that can trigger a relay on axis movement, we use it to drive the timer for the lube pumps,  BUT by the time the Brake reacts it it will be too late. Servo error or lost steps would be the results

We worked on this for a while a long time ago. Even Art suggested it would not work without driver level intervention.

NOW what we did get to work fairly well was rewriting the CAM post to enclude the Brake function before and after the index move that worked well for CAMed situations. BUT it could not do interpolated 4th axis moves well. Abig mess actually.

BUT you never know, maybe ?

6850

General Mach Discussion / Re: mach's rounding of measurements?

« on: April 29, 2010, 10:03:43 AM »

> Its remembered and done when it can do it..
>
> Think of it this way. A position counter of distance, where the
final output is a stepvalue, if the number of steps increases, a step
goes out, if it decreases, a reverse step is poutout..
>
> double movement = .000001;
> double totaldistance = totaldistance + movement
> totalsteps = (int) (totaldistance / stepsPermm);
>
> With this method, no step can ever be lost due to rounding..
>
> Thanks,
> Art
> www.artofcnc.ca
>
******************************************************************>
> Hi ART, I know we have had this converstion before but I am not
clear
> of the results( old age). WHat happens if Mach cannot make the
> commanded move with 1 step. Say the commanded move is .0001" and
the
> machine resolution is .001" per step. How is the differential
handled?
>
********************************************************************
>
> --- In mach1mach2cnc@yahoogroups.com, Art Fenerty <fenerty@>
wrote:
> >
> > Hi:
> >
> > No, mach wont skip anything. IT uses max number of decimals
> internally, but the DRO';s are set to display only 4. ( They can
be
> told to display 16).
> >
> > The DRO's though, are separate code. They dictate if the right
> number of pulses went out. If, at the end of a program, the axis
is
> wrong, but the DRO is right, then the machine lost pulses that
were
> sent. There can be no questions about it. In this case, where the
Z
> lost position ( it is usually the Z that does this on long 3d
> programs ) the Z aacel shoudl be turned down. Also, you migth
want to
> set a dir prechange of 5 or so in the motor tuning to make sure
its
> not a direction signal issue.
> > As a last report, try sherline mode in the ports & pins, this
> will limit you to 1/2 of the max velocity for any kernal speed,
but
> stretches the pulses out to a minimum of 40us. IF it doesnt lose
> then, the wiring shodul be checked for good coneection, or the
> optocouplers checked to see if they are too slow.
> >
> >
> > Thanks,
> > Art
> > www.artofcnc.ca