comp in control error-Ver. 9

[Smit]

Hi folks,

I program w/ compensation in control, left, almost always. On occasion version 9 will not run correctly. On the latest mistake it runs properly over 6 lines in a chain, then cuts the 7th on cutter center line. Scrap part.When I leave .0001 stock on XY it cuts perfectly. Same geometry in V8.1.1 perfect every time. Two other times I've seen this compensation in control thing happen, but have caught it before sending the program to the floor. Both times V8.1.1 has run it correctly. Has anybody else seen this happen, and have a fix? I guess I'll send a couple files to QC and see what they have to say about it. It's been hard to gain confidence in Ver. 9 so far.

Thanks, Smit

[ROB]

i've had the same problem with ver.9

using c/comp left in control

luckly i did't scrap my parts i reported to

mastercam and send my file to be checked

they found a bug, and so far i haven't seen any fix for it,so i went back to use ver 8.1

we do a lot of contouring and pockets and can't aford to risk a scrap part.

[Scott Bond]

Hi all

quote:

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Hi folks,

I program w/ compensation in control, left,

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Has any of you seen This bug in Wear / left??

[chris m]

Has anybody seen this in Lathe, or is it Mill only?

[Guest CNC Apps Guy 1]

I never use Comp in the control exclusively. I use wear comp and have not see these problems.

 

JM2C

[mikhael gutman]

HI!

I start use mastercam from ver 6

From begining i was trying to use comp, in control, never was compl. perfect include verification, So i start to use

WEAR left (comp in computer and control left).Never problem.

[Thad]

quote:

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I use wear comp and have not see these problems.

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How, exactly, does this work? What's the difference between cutter comp and wear comp?

 

We have quite a few problems with the Okuma mill when using cutter comp in some tight areas. There is still plenty of room for the tool to move at least the radius...but the machine goes to places that we don't want it to and it violates the part. Running Fadals for 7 years, I had maybe 2 problems with cutter comp. Running this 10 yr old Okuma, it's a weekly struggle. Sheesh!

 

Thad

[mikhael gutman]

To that

I understand that cut comp. Mean comp. Left(right) in control , so g-code has real (not offset) drawing numbers. The actual cutter diam(rad)must be input to the specified register to produce an accurate part profile. So “D” value is positive. In this situation I never had problem with Okuma control.(mastercam has problems to work this way)

"Wear" option Mean g -code has offset drawing numbers, So "D" value-the defference between the actual and designated tool diam.

Alarms start when you use “wear” option with negative “D” value if you using lead in- lead out perpendicular+ rad, But work fine if use lead in – lead out as tangent + rad

[Rick Damiani]

quote:

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How, exactly, does this work? What's the difference between cutter comp and wear comp?

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There are basicly four cutter comp conditions you can select from when using MasterCAM. They are:

 

computer (OFF) control (OFF):

In V9, this is 'OFF'

 

Cutter centerline moves along contour. Usually bad, unless you are engraving.

 

computer(ON) control (OFF)

In V9, this is 'Computer'

 

Cutters must exactly match the programmed size. Does not allow for adjustment at the machine.

 

computer(OFF) control (ON)

In V9, this is 'Control'

 

Cutters can be any size (within reason). Cutter diameter must be set at the control by entering the diameter in the appropriate D register.

 

computer(ON) control(ON)

In V9, this is 'wear' or 'reverse wear'

 

Cutters must be the same nominal size as was programmed, but can be adjusted to compinsate for tool wear.

 

Pros and cons:

 

Off:

Part will be under/over size by the cutter radius. Good for engraving, bad if you are doing (almost) anything but engraving.

 

Computer:

Will never generate an alarm on your control, but it means you can't use re-ground cutters and it forces the operator to 'fix' out of spec parts by changing the cutter.

 

Control:

Can use any convenent cutter (within reason) but may generate an alarm if the chosen cutter cannot be sucussfully compinsated to your geometry. Generally, you need to use a lead-in line that is equal to or grater than the cutter radius or compinsation will not be sucussful and likely geneate an alarm. Failure to include a lead-in line will result in compinsation taking place with the tool in contact with the workpiece, which is generaly a good way to make scrap. This puts G41/G42 codes in your .NC file and makes your toolpath follow the contour you drew. i.e. if the D register for the tool is zero, it will work the same as setting compinsation to 'OFF'

 

Wear:

This allows you to compinsate for the nominal diameter of the cutter in MasterCAM, and allows the operator to 'fix' out of spec parts by entering the desired correction in the appropriate 'D' register for the cutter. You still need a lead-in line as above, but the lead-in line can be very small as it only needs to be as long as the likely correction value. MasterCAM does the compinsation *and* puts G41/G42 codes in your .NC file. If the 'D' register for the cutter is set to zero, it works the same as 'Computer' above.

 

Reverse wear is the same as wear, with one important difference: it puts a G41 in the code if you are compinsating *right* in the computer, and a G42 if you are cominsating *left*. i.e. the cutter comp is opposite of what the computer comp is. This keeps you from having to enter a negative value in the 'D' register if your cutter is smaller than the nominal size. It's also a good way to make scrap if you switch from wear to reverse wear without making sure that the operator knows what you are doing.

 

Hint: Don't switch from wear to reverse wear in the same program if the operator is bigger than you....

 

[ 07-14-2002, 01:23 PM: Message edited by: Rick Damiani ]

[Thad]

Thanks for the long explanation, Rick.

 

It sounds like wear comp funtions the same as, what I refer to as, cutter comp. The machine operator can adjust the tool dia/rad to "comp in" the part. The only difference is that instead of putting the tool dia/rad in the offset page, you input the difference between the programmed tool dia and the actual tool dia. For example, if a 1" cutter was programmed and you use a .990 resharp, you would enter -.01 dia. (or -.005 if your machine uses a radius value)?

 

Mikhael mentions problems with using negative dia/rad values. Is this only on certain (Okuma)controls?

 

Mikhael, what problems did you have with MC that you are referring to here?

quote:

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In this situation I never had problem with Okuma control.(mastercam has problems to work this way)

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Thad

 

[ 07-15-2002, 10:15 AM: Message edited by: thad ]

[Rick Damiani]

quote:

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For example, if a 1" cutter was programmed and you use a .990 resharp, you would enter -.01 dia. (or -.005 if your machine uses a radius value)?

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Exactly.

 

quote:

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Mikhael mentions problems with using negative dia/rad values. Is this only on certain (Okuma)controls?

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I'm not famialr with that control, but if it does alarm when the radius comp is negative, then you would want to use reverse wear comp. That way you could compinsate for wear and/or re-ground tools without having to enter a negative value in the D register.

[mikhael gutman]

Hi!

There is problems with using negative dia/rad values in Okuma control?

Don't blame MC.

To avoid this , when you do lead in (lead out) don't use line"perpend"-rad,use tangent-rad.It help.

[Smit]

Well, it got me again. I hate going backwards, but I am going to start using Version 8.1.1 again, until a patch is delivered that fixes the problem reliably.

[MetalMarvels]

ARGHHHHHHHH. I read this thread. I thought I understood it. Then I went and used cutter comp in control in MC9SP1 and DIDN'T set the diameter in the control. NUTS - $45 of 6061 in scrap pile when the cutter went down the center of the geometry. (picture me beating head on wall on spot that says "pound head here in event of stupidity") I can't say that this thread didn't warn me....... Gonna switch to wear comp... I wish I had paid closer attention to this (and other) threads.

 

Thanks for all the good info over the years,