Messages

6441

General Mach Discussion / Re: How to recover from power interuption?

« on: September 16, 2010, 11:34:26 AM »

Looking at your accuracy requirements the ONLY way to do this is to run a UPS   "AND " a very large battery bank. That way there is NO interuption of cut.

With your resolution requirement you cannot even "stop" the program without effecting the finish cut. SO the machine must remain running thru the  power outage.

It would be very hard to create a macro to be to retract the cutting bit in a method that would not cause harm to a finish cut. COULD be done but very complicated.

(;-) TP

6442

General Mach Discussion / Re: Soft stop at limit switches

« on: September 16, 2010, 10:41:08 AM »

1. Some machines stop faster when there is a controlled stop instead of killing the drive clock.
2. On stepper drives, hitting "stop" usually results in lost steps, causing the need to re-reference position. So operators usually ponder whether it's really necessary to hit "stop" but maybe "line feed" does as well. That's not the sense of a "stop" button to ponder before hitting it!
3. Sometimes, soft limits simply don't work.
  3a) Sometimes soft limits just are switched off by operator
  3b) Some machines do not have a rectangular working area!
  3c) Some machines have changing dimensions of working area.
  3d) If soft limits always worked, they would be useless.
4. At some machines (usually smaller ones), the impact on the machine by the abrupt stop when triggering the limit switch is even harder than that one caused by crushing into the elastic dead stop.


#1  WRONG, if you stop the pulses to the drive while it is enabled THAT is the fastest you can stop the axis period. You will have FULL dynamic braking

#2 IF you run a program that has NOT been tested for clearance SHAME on you. You need to fire the operator DON't blame the machine. The machine is basically dumb as a box of rocks. It can ONLY do as it has been told. The operator on the other hand is suppose to be intelligent.

#3 The only time i have seen Soft limits fail is IF they were not turned on OR they were turned off.   Operator error

#3a Retrain or fire the operator. The "second" time he turned OFF a "safety" he would be fired so fast he would think he had a stroke

#3b  It has nothing to do with the subject. Soft limits are there to protect your "part" in the event you really screw up and have not tested for proper clearances. Hard limits are there to protect the machine.

#3c (;-) I have never seen a machine that could GROW. They all have a physical limit to movement

#3d  Makes no sense(;-)

4.    WRONG again it won;t happen.  Worse case IF you hit the axis hardstop wide open you ARE going to tear up the machine. Best case it has to be inspected and retested  for accuraccy even for a light tap. AND IF the operator hid from me a light tap hardstop see #3a

Sport I have been around this industry a long long time. What you are asking for is something to REPLACE an incompenent OPERATOR.  In the old days yes there were slowdown switches on machines. they simply dropped the feedrate down. AND that was ONLY because there was NOT enought CPU power to do otherwise. Today you have very powerfull CPU and PLC to do the job. AND they do a much better job than the old mechanical machines ever did.

Full 6 axis control (;-). Mach can move on 6 axis BUT does not have any kenimatics as to KNOW where it is. It is just a GOOD low co$t  pulse generator. That is why you cannot JOG in full 6 axis mode.

Now what exactly are you expecting for $175 there are limitations.

NOW IF you need all those bells and whistles they can be had but BRING your checkbook full of $$$$$$$$ cause it is a little MORE than $175.

(;-) TP

6443

General Mach Discussion / Re: Soft stop at limit switches

« on: September 12, 2010, 02:21:24 PM »

You CAN have mach turn on Softlimits through a script I believe BUT softlimits CANNOT work UNTIL the machine has been referenced(;-). Even a modern High $$$ cnc has to follow the same process. Yes I know some have linier encoders that retain the position values(;-) Mucho Bucks compared to mach.

LOOK at Rogers encoder board I think the latest version can recover the lost position or at least has the potential to do so AS LONG as the power has not been lost. You can also do it with MACH brains and shaft/linier encoders.  I know in the past we could using Macros and the brains.

Just a thought, (;-) TP

6444

G-Code, CAD, and CAM discussions / Re: gcode from CAMBAM not running

« on: September 11, 2010, 10:55:08 PM »

It does not like the double brackets  (  () ) It thinks the inside brackets are nested inside the outter ones.

(;-) TP

6445

G-Code, CAD, and CAM discussions / Re: gcode from CAMBAM not running

« on: September 11, 2010, 07:24:41 PM »

AND the file line in question reads?

(;-) TP

6446

General Mach Discussion / Re: How to recover from power interuption?

« on: September 11, 2010, 04:50:08 PM »

It will ALL depend on the tolerance you work with. Hood has the correct and most common method. It is FAR easier to restart an ACURATE machine than try and recover after an outage. It will also depend on when you loose power. During a rough cut no problem, during a finish cut?? BIG problem if you have low tolerance finishes say sub .001"

Unless you have a UPS big enough to run the entire CNCmachine you have a very limited time to react AFTER the power shuts down. Usually about 1 sec or less before the energy stored in the CAPS have been used up. This does NOT give you enought time to react and finish a stored position solution before the machine looses position.

NOW even if you have UPS capacity to run the machine during this time as soon as it does shut down and the drives loose power the axis's can DRIFT and loose position unless you have axis brakes to hold it on position(now we really get complicated)

With Hoods method all you have to do is re home and restart somewhere near where you left off.

I would try and only machine during the times that are LEAST likey to have a power outage maybe at night?

Just a thought, (;-) TP

6447

General Mach Discussion / Re: Mach 3 doing wierd things

« on: September 09, 2010, 11:02:06 AM »

To continue Yes to what Hood asked. When you say the dros changed did the machine MOVE at the same time.

DO you used tool offsets?  Tool length offsets??  From the tool table?

How about work offsets G54,G55,G56,etc  ?

What macros do you use at tool change?? M6start,M6end??

What macro do you use for ATZ

Does this ever accur on jobs that do not have a tool change?? Maybe you need to test that??

Do you have a simple job that this occurs a lot of times?? So we can run a test??

(;-) TP

6448

General Mach Discussion / Re: Mach 3 doing wierd things

« on: September 09, 2010, 10:52:36 AM »

OK so there WAS a time when this did NOT occur??  What you are describing sounds like hardware MISSED steps. IF it were Mach acting up the DRO would NOT be showing the correct values. When you say the DROs are correct BUT the origin has changed that means somewhere steps were missed and the tool is no longer in the correct position.  Is your lube pump working?? Dry ways on a BP can causes extra drag. IF you are using the original motros and Geckos then you are NOT blessed with a lot of extra torque.

Just to make sure(;-) When you GO TO ZERO the DROs read zero BUT the tool is NOT at the origin correct?

To recap your REinstall(;-)

When you upgraded Versions DID you use the same XML??

DO you have an original version of the XML stored away as a backup??  SURE YOU DO right(;-).

IF you have a backup of the xml then copy it over to the Mach directory.

IF you don't start from scratch and build a NEW one.

Next Make sure there are NO extra XMLs in the mach directory(;-)

Delete ALL the mach backups in the backup directory(mach will rebuild them) If you don't then mach has possable access to bad data.

Just some thoughts, (;-) TP

6449

General Mach Discussion / Re: Mach 3 doing wierd things

« on: September 08, 2010, 07:16:15 PM »

Sorry Guys I just noticed this one.

First question Did the machine ever do this while hooked to the SS??

(;-) TP

6450

General Mach Discussion / Re: Looking for some advice on a project

« on: September 06, 2010, 06:05:25 PM »

See IF you can find a copy of the scene as a coloring book page. Then convert it to lines with Inkscape(free)

http://www.patrioticcoloringpages.com/memorial-day/009-iwo-jima-picture-to-color.html

Just a thought, (;-) TP