Moves not in the program causing problems. How do I stop them?

[Slugo]

First things first.
1997 Fadal VMC4020 88HS control.
Not a bad machine the first Fadal I have worked with. I have worked with just about every other control and machine made so not new to this.

The problem.
The machine makes moves not in the program when I start running it. If I have a positive Z offset of more than 4" the head hits the positive limit switch before the tool change and alarms out.
What parameter do I change to make this stop happening?

TY in advance.

 

[Speedie]

Put in a Z negative because all offsets are set from toolchange (Cold start) position to top of work UNLESS you have a Z offset in your fixture offset. What machine tool have you worked on that had a positive offset for a tool? This is typically a measurement from its machine zero position to the top of your work on virtually all machines.

 

[Slugo]

Put in a Z negative because all offsets are set from toolchange (Cold start) position to top of work UNLESS you have a Z offset in your fixture offset. What machine tool have you worked on that had a positive offset for a tool? This is typically a measurement from its machine zero position to the top of your work on virtually all machines.

I have negative numbers for my tools. I have a positive number in the Z work offset.

 

[Speedie]

Well you screwed up those numbers.

 

[Speedie]

Or your in g90 mode

 

[13engines]

Well you screwed up those numbers.

How so? If by chance he's using a Tool Setting device that is lower then his current workpiece Z0. plane, he would need a positive Work Offset Z setting.

Are you using an original Fadal Tool Change Macro or Program? Not familiar at all with Fadal controls, but seems a Tool Change Macro would have some way built in to ignore any Z settings, be they positive or negative. That 4" must put you just outside of the free Z travel range you might have if your machine is sporting a Carousel Type Tool Changer.

 

[Speedie]

How so means he is posting a complaint.

 

[Slugo]

How so? If by chance he's using a Tool Setting device that is lower then his current workpiece Z0. plane, he would need a positive Work Offset Z setting.

Are you using an original Fadal Tool Change Macro or Program? Not familiar at all with Fadal controls, but seems a Tool Change Macro would have some way built in to ignore any Z settings, be they positive or negative. That 4" must put you just outside of the free Z travel range you might have if your machine is sporting a Carousel Type Tool Changer.

You are correct my tool setter is lower than my part and therefore I have a positive number in my Z work offset.
Its not the toolchange that makes this move it happens before the M6 line. The Z goes home then the table moves to some home position (that is not actually machine home) in X and Y and then the Z goes up again and then the tool change. All is fine until I have a Z positive of more than 4" and then I hit the Z limit.

 

[Slugo]

Well you screwed up those numbers.

No I did not. I have set many machines up this way and never had a problem.

 

[Speedie]

Post your code

 

[13engines]

You are correct my tool setter is lower than my part and therefore I have a positive number in my Z work offset.
Its not the toolchange that makes this move it happens before the M6 line. The Z goes home then the table moves to some home position (that is not actually machine home) in X and Y and then the Z goes up again and then the tool change. All is fine until I have a Z positive of more than 4" and then I hit the Z limit.

Hi Slugo, Didn't mean to imply that it was your tool change and/or program that was causing the overtravel. I meant only that 4" may have been more then the free movement you might have above tool change Z height position. As carousel changers have a Z height for change but a plus Z height for Tool release.

Anyway... that still doesn't solve the problem. You're probably right that a parameter needs changing or again, you're not operating with an original Fadal Tool Change Macro in the background. It should ignore any Z Work Offset Settings. Maybe post the Tool Change Program and a bit of the normal programming that causes a problem.

Where are all the Fadal guys around here? Someone must have run into this before. I really only know Fanuc speak.

 

[Slugo]

Hi Slugo, Didn't mean to imply that it was your tool change and/or program that was causing the overtravel. I meant only that 4" may have been more then the free movement you might have above tool change Z height position. As carousel changers have a Z height for change but a plus Z height for Tool release.

Anyway... that still doesn't solve the problem. You're probably right that a parameter needs changing or again, you're not operating with an original Fadal Tool Change Macro in the background. It should ignore any Z Work Offset Settings. Maybe post the Tool Change Program and a bit of the normal programming that causes a problem.

Where are all the Fadal guys around here? Someone must have run into this before. I really only know Fanuc speak.

I didn't think you were implying that. I was just trying to be cleaer. I have no idea how to acess the macros on this machine.
There is no problem if the Z offset is a negative number.
Yes I agree WHERE are all the Fadal guys I figured one of them would have laughed at my problem and offered the solution by now!

 

[Speedie]

I did and I did you are not complying. Post your code and a picture of your fixture screen and offset screen

 

[604Pook]

I always use the top of my part as the Z zero when programing on my Fadal which 99.9% of the time is a negative number.

I then just use the mass modify function in tool offsets to adjust all the tools to the appropriate Z height. Only time I have ever had it limit out in positive Z is when I set the clearance plane to high in Cam, when working on tall parts.

 

[ducesrwld]

these fadals can do some weird things behind the scenes some of which i still haven't figured out why.....

first off go into command mode and type in setp and see what format you are in you want to be in format 2. several times i've brought in fadals and forgot about the formats and it'll screw with your programs and movements.

at the end of my programs i always do a G0 movement to move the table to a good position to stop if I put too big a Z move I've had it limit out on Z even when I take the Z home movement out of the code.

Some things on the Fadals I just put up with as there are bigger problems to deal with....

 

[Slugo]

these fadals can do some weird things behind the scenes some of which i still haven't figured out why.....

first off go into command mode and type in setp and see what format you are in you want to be in format 2. several times i've brought in fadals and forgot about the formats and it'll screw with your programs and movements.

at the end of my programs i always do a G0 movement to move the table to a good position to stop if I put too big a Z move I've had it limit out on Z even when I take the Z home movement out of the code.

Some things on the Fadals I just put up with as there are bigger problems to de

these fadals can do some weird things behind the scenes some of which i still haven't figured out why.....

first off go into command mode and type in setp and see what format you are in you want to be in format 2. several times i've brought in fadals and forgot about the formats and it'll screw with your programs and movements.

at the end of my programs i always do a G0 movement to move the table to a good position to stop if I put too big a Z move I've had it limit out on Z even when I take the Z home movement out of the code.

Some things on the Fadals I just put up with as there are bigger problems to deal with....

I am running format 1. I will try format 2 and see if it helps Thanks!
Finally someone listened to me about the moves the machine makes that are NOT in the program!

 

[Speedie]

these fadals can do some weird things behind the scenes some of which i still haven't figured out why.....

first off go into command mode and type in setp and see what format you are in you want to be in format 2. several times i've brought in fadals and forgot about the formats and it'll screw with your programs and movements.

at the end of my programs i always do a G0 movement to move the table to a good position to stop if I put too big a Z move I've had it limit out on Z even when I take the Z home movement out of the code.

Some things on the Fadals I just put up with as there are bigger problems to deal with....

That would be because you have the H # precalled so at the end of the program G0 H0 Z0 works. If you simply put G0 Z28 it will go 28"s from then tool height you set. Same as any machine. No voodoo

 

[Speedie]

I am running format 1. I will try format 2 and see if it helps Thanks!
Finally someone listened to me about the moves the machine makes that are NOT in the program!

Format 1 sucks

 

[ducesrwld]

That would be because you have the H # precalled so at the end of the program G0 H0 Z0 works. If you simply put G0 Z28 it will go 28"s from then tool height you set. Same as any machine. No voodoo

I take all the home movements out and just put in small G0 movements. Its like the M30 has a parameter attached to it that automatically homes the machine out in Z whether you want to or not. If I put too big a G0 Z movement in it will error out when it homes.

I've never looked further into this just tweak the programs and run with what it does. On extended Z machines it gets quite annoying. I'm sure there is a rhym and reason it does it just has never been high on the priority list to figure out.

 

[Nmbmxer]

Are you tried canceling the tool length offset before homing the axis?