Moving X and A together(Thread)JUST CRAWLS

[cncot]

Could someone please tell me how to determine machine coordinates (what are machine coordinates?) of the z and y axis at the center line down the x axis which are required to be put in the parameters mentioned above.??? I can’t find any explanation of what this means. Please help! It’s still crawling and I need to fill in the 2 parameters. It’s a Bridgeport knee mill with the centroid A axis on the right hand end of the table facing left.
Thanks, Mike
Mark: Thanks, please stick with me. I will run your mdi tests . I already did some.

[tblough]

ALT+D will switch the DRO from WCS to machine coordinates.

[cncot]

Thanks cncsnw Mark.
I did your requested tests listed in your previous post. Everything was as expected until you added x1, then it started crawling.
I even tried 30 degrees over 1", still crawled, but the feedrate went up to 0.3.
Setting Parameter 94 t0 2049 did not help, but appears to be required..?
1-2 parameters have been changed and they are documented in the posts above, so a new report file is not needed.
Mark, You remember writing a special PLC for me? (2 Spindles, one 25000 rpm) could that be affecting spirals?
dpascucci indicated that I needed to enter the machine coordinates of the y, z centerline of A axis into parameters 116 and 117. Its a Bridgeport knee mill, so the knee moves up and down and the ram moves in and out, so I can't see how to measure these coordinates.. are they needed by me? How to proceed?
Please help, I am SOOO.. stuck, and the spiral thing is necessary for me.
RSVP
Warm Regards, Mike

[cncsnw]

I did your requested tests listed in your previous post. Everything was as expected until you added x1, then it started crawling.

In the list of moves I suggested testing, the first appearance of "X1" was in:

Code: Select all

G1 G91 F60 X1

Do you mean to say that G1 G91 F60 X1 "crawls", even when there is no rotary movement combined with it? If so, then the subject line of this thread should be changed, since the problem does not in fact relate to the inclusion of the A axis.

The next appearance of "X1" was in:

Code: Select all

G0 G91 A360 X1

Did that move "crawl" as well, even though it was supposed to be in rapid mode?

Setting Parameter 94 to 2049 is not required. If you are not using G93.1 mode for your moves, then rotary moves should be no different with P94=1 or P94=2049. That setting does allow the graphics preview (backplot, F8/Graph) to display the effect of rotary movement; but it should not affect the movement of the axes in normal units/minute feedrate moves or rapid moves. Likewise, Parameters 116 and 117 are not relevant except for the graphics preview and for G93.1 mode.

No, the number of spindles on your machine, and your methods for controlling spindle speed, do not affect the movement of your servo axes.

[cncot]

My apologies, Mark, It was late at night and I was tired after 2 emergencies, rushing:
As a former programmer, I know the importance of being precise....
SO:
G1 G 91 F60 X1 runs 1 sec and all previous commands ran fast as expected,
Then when you add A combined with X1 you get:
G0 G91 A360 X1 crawls eleven tho its a rapid. Hours to finish..
G1 G91 F3600 A 360 X1 also crawls; 3+hours to finish it DOES finish Feed rate display between 0 and 0.1
G1 G91 F3600 A 36 X1 yields a Feedrate of 0.3
please help, Thanks, Mike

[cncsnw]

Okay, so:
- Moving individually, both X and A can move at appropriate feedrates and rapid rates
- A move that combines X and A moves very slowly, whether it was programmed as a rapid, or with a reasonable feedrate.

When were you last able to do combined X-A moves at the correct speed?

Or was this week the first time you tried anything like that?

I compared the report you posted this week (10/2/23) with one you sent me last year (10/13/22). The only differences that stand out are that you have reduced the Y and Z axis max rates each to 50 in/min, and you have reduced the Y and Z axis DeltaVmax values each to 0.1 in/min.

As far as I know there is no reason that the Y and Z rapid rates or DeltaVmax values should affect X and A movement. However, if you did not have a compelling reason to make those changes, you might try changing them back to more realistic values (e.g. max rates of 200 in/min, and DeltaVmax values of 3.0 in/min).

[cncsnw]

Found it.

The problem is that you have set Parameter 38 to a value of 10.0. You do not need to use Parameter 38 at all. Change it to zero, so that any move can go at any requested speed, as long as it does not exceed the max rate of any included axis.

Did you ever notice that you could do a rapid move on X at 220 in/min; and a rapid move on Y at 50 in/min; but that when you tried to do a rapid move on X and Y together, it only went 10 in/min?

[dpascucci_support]

Found it.

The problem is that you have set Parameter 38 to a value of 10.0. You do not need to use Parameter 38 at all. Change it to zero, so that any move can go at any requested speed, as long as it does not exceed the max rate of any included axis.

Did you ever notice that you could do a rapid move on X at 220 in/min; and a rapid move on Y at 50 in/min; but that when you tried to do a rapid move on X and Y together, it only went 10 in/min?

Haha, you found it at the exact same time I did, was just about to comment on P38 myself.

[cncsnw]

A good example of a software feature that was added to benefit one or two customers who could not be bothered to provide an adequate power supply to their machines; which now everyone else is stuck with and has to watch out for. Similar to the direction-specific fast jog rates....

[cncot]

THANKS!!!! YOU GUYS ROCK ! PARAMETER 38 WAAS THE PROBLEM. My dealer set up much of the setup programming when I had finished the hardware, including 38. I didn't have a clue! (still don't unfortunately. I am 74. I forget most everything I knew when I don't use the Mill for months...)

Your questions:
When were you last able to do combined X-A moves at the correct speed? Never
Or was this week the first time you tried anything like that? YES
Did you ever notice that you could do a rapid move on X at 220 in/min; and a rapid move on Y at 50 in/min; but that when you tried to do a rapid move on X and Y together, it only went 10 in/min? NO, never

I compared the report you posted this week (10/2/23) with one you sent me last year (10/13/22). The only differences that stand out are that you have reduced the Y and Z axis max rates each to 50 in/min, and you have reduced the Y and Z axis DeltaVmax values each to 0.1 in/min.

As far as I know there is no reason that the Y and Z rapid rates or DeltaVmax values should affect X and A movement. However, if you did not have a compelling reason to make those changes, you might try changing them back to more realistic values (e.g. max rates of 200 in/min, and DeltaVmax values of 3.0 in/min).

I WAS SETTING UP AND TESTING. ITS A BRIDGEPORT SERIES 1 KNEE MILL. WE MOUNTED THE A AXIS (HEAVY) ON THE RIGHT HAND END OF THE TABLE. AFTER THAT, I STARTED GETTING OVERCURRENT ( X AND Y ALSO) TRIPPING WHEN THE X IS NEAR FAR RIGHT (BIG LEVER ARM, BIG WEIGHT,,,). IF I SLOWED IT DOWN, IT QUIT TRIPPING, SO I RANDOMLY PICKED MUCH SLOWER NUMBERS AND LEFT IT.
I AM OLD AND SLOW, I FIGURED I WOULD HAVE MORE TIME TO REACT WHEN THE DUMMY(ME) MADE SOME FOOL MISTAKE!! THIS IS A HOBBY, NOT A BUSINESS.

DO YOU THINK THESE NUMBERS WILL CAUSE TROUBLE IN THE FUTURE? I COULD PROBABLY INCREASE THEM THRU EXPERIMENT. I DONT FEEL THE SLOWNESS MUCH, IT MATCHES ME! HA HA

Continuing..
You wrote: Parameters 116 and 117 are not relevant except for the graphics preview and for G93.1 mode.

OK, say I want to use the graphics preview. ( I DO). I have to enter Machine coordinates of the A centerline. How do you determine the 2 numbers when the knee goes up and down and the ram moves in and out and around? I am stumped because I can see no reference point. I don't know how machine coordinates were established in the beginning... I could display machine coordinates, then touch off on a 2 inch polished bar in the rotary, and compensate for the 1 inch. Also, what part of the ram is 0 at touch off? Isn't this tool length dependant? (Also have 3 rotary spindles, and a lathe toolpost Nothing is constant!..) But this touch off would not be correct next time I move the ram or knee (often) or change spindles/toolpost. My brain is smoking !!

MANY THANKS
Warm regards, Mike