FLow control question

[Perry Fisher]

I am programming a oven door window frame that comes off the die straight for packaging purposes but is required to be bent to 90° at assembly. The part print has several dimensions based on the 90° bend. I have cobbled up jig to hold the part at 90° but I want to check the angle immediately after DCC alignment. I know I can use variables & IF/THEN type statements to either continue running or stop depending on the angle dimension. What I don't know is how to program it. Any and all help is appreciated.

[Perry Fisher]

I think I found what I need in the code samples but I'm still open to suggestions.

[rangerboat72]

I think I found what I need in the code samples but I'm still open to suggestions.

So, are you saying that this post is not closed?

I'd offer some suggestions but I honestly haven't hade time to fool with coding too much...

[Perry Fisher]

Yes still open. I'm not confident I'll figure it out on my own.

[rangerboat72]

Is this a full layout program that you are just wanting to skip items to get to the angle measurement later in the program? Maybe if you can supply a picture of the door with your setup (and possibly part of the drawing requirements you are wanting to check), I might be able to assist.

[kmcmm]

You can use Select/Select End along with Case Select/Case End to specify portions of the program to run i.e. the whole program, feature 2, feature 3, so on and so forth. If you need some examples let me know.

[Perry Fisher]

The quality of the attachment is not good but maybe you can see what I need.

The part comes off the tool straight but needs to be bent and held at 90° ±1°. I am bending the part by hand around an angle plate using jackscrews to fine tune the angle to 90° on the CMM. I want to take hits and create the necessary lines to verify the 90° angle at the front end on the program. If the angle is out of spec I want the program to end for tweaking the angle the try again. If the angle is good I want to program to continue.

This works but is there a better way?

DIM D_ANGLE = 2D ANGLE (TRUE) FROM LINE ANGL1 TO LINE ANGL2 ,$
GRAPH=OFF TEXT=OFF MULT=10.00 OUTPUT=REPORT
AX NOMINAL MEAS +TOL -TOL DEV OUTTOL
A 90.000 88.132 1.000 -1.000 -1.868 0.868 <--------
MOVE/CLEARPLANE
IF/D_ANGLE.A.MEAS>91.000
GOTO/END
END_IF/
IF/D_ANGLE.A.MEAS<89.000
GOTO/END
END_IF/


Thanks

[John Kingston]

You could also use a label and a loop to send it back to the beginning of the program.

[Farmer]

I have had to do something very similar for a hinge. This is how I did it - the program tells you what way to adjust the angle and by how much:

DIM REF1= 3D ANGLE (TRUE) FROM PLANE DCCDTMD TO PLANE DCCDTMA ,$
GRAPH=OFF TEXT=OFF MULT=10.00 OUTPUT=BOTH
AX NOMINAL +TOL -TOL MEAS MAX MIN DEV OUTTOL
A 87.150 0.200 0.200 87.000 87.000 87.000 -0.150 0.000 ---#-----
IF_GOTO/(REF1.A.MEAS<86.8)OR(REF1.A.MEAS>87.2),GOTO = L2
GOTO/L5
L2 =LABEL/
ASSIGN/V1 = REF1.A.DEV
IF_GOTO/REF1.A.MEAS>87.2,GOTO = L3
IF_GOTO/REF1.A.MEAS<86.8,GOTO = L4
L3 =LABEL/
COMMENT/OPER,"PULL TOP TOWARDS. Error = "+V1
GOTO/L1
L4 =LABEL/
COMMENT/OPER,"PUSH TOP AWAY. Error = "+V1
GOTO/L1
L5 =LABEL/
MOVE/POINT,0,50,100

Give me a shout if you need any furtehr explanation.

[Perry Fisher]

Thanks Farmer. This is what I need to do. It took me a minute to figure out your L1 label restarted the program.

You should post this in the CODE section of the board.

[Roberto]

The quality of the attachment is not good but maybe you can see what I need.

The part comes off the tool straight but needs to be bent and held at 90° ±1°. I am bending the part by hand around an angle plate using jackscrews to fine tune the angle to 90° on the CMM. I want to take hits and create the necessary lines to verify the 90° angle at the front end on the program. If the angle is out of spec I want the program to end for tweaking the angle the try again. If the angle is good I want to program to continue.

This works but is there a better way?



Thanks

I took at look at the print, and the angle you're checking has a note (Note 3).
Per that note you're allowed to restraint the part to 90.0 degrees prior to take measurements.

In my opinion, you don't have to do nothing but squaring the part. I have a lot of sheet metal parts where material is so thin or flexible.
and that's the way we approach it.

Just my opinion.

[Perry Fisher]

I took at look at the print, and the angle you're checking has a note (Note 3).
Per that note you're allowed to restraint the part to 90.0 degrees prior to take measurements.

In my opinion, you don't have to do nothing but squaring the part. I have a lot of sheet metal parts where material is so thin or flexible.
and that's the way we approach it.

Just my opinion.

I am restraining it but also need to verify the angle is at 90° before running the program. I actually found the correct placing of stops and magnets to hold the part at 90° but I still want to verify the angle first.

How do you prevent long thin parts from flexing with probe hits? I have not run into that problem YET but this is the first of 10 appliance parts I have to program. One part is the bottom of an oven warmer drawer stamped from .024" max material thickness & 19" x 21" . I can see all kinds of problems keeping that part from moving when the probe hits it.

Thanks for your input Roberto.

[Roberto]

I am restraining it but also need to verify the angle is at 90° before running the program. I actually found the correct placing of stops and magnets to hold the part at 90° but I still want to verify the angle first.

How do you prevent long thin parts from flexing with probe hits? I have not run into that problem YET but this is the first of 10 appliance parts I have to program. One part is the bottom of an oven warmer drawer stamped from .024" max material thickness & 19" x 21" . I can see all kinds of problems keeping that part from moving when the probe hits it.

Thanks for your input Roberto.

Of course, that does not mean you going to accept samples over-formed or wide open (our set-up man knows that).

I will use a protactor just to verify the angle. And for preventing parts from flexing with probe hits, some times we use gages, or L-brackets with magnets against the formed wall.

[Farmer]

Thanks Farmer. This is what I need to do. It took me a minute to figure out your L1 label restarted the program.

You should post this in the CODE section of the board.

Ah yes well spotted! Good to have a deliberate mistake now and again I find ;o)

[jjewell]

One way to measure thin parts, is to make sure the probe is hitting the sheet metal, not along the shank angle. On a 45(or other) deg angle is what I try to use. It takes more gram force to push the probe up(overtravel) into the TP2/20 than to trigger sideways. The overtravel is also greater sideways than straight into the trigger also. You may still notice a tiny bit of movement with the probe on an angle, but that is just the machine overtravelling past the trigger point.

I have conducted many tests ( a long time ago) and the accuracy is still acceptable, even with .020" material. The tolerances are not that tight on thin material, which helps.