VF2 overtravel question

[Turbo442]

I noticed my 2005 VF2 is allowing me to exceed the normal limits of travel. 30" x, 17" y, 20" z. Homing the machine everything zeros correctly. X to the left, Y to the front and Z up. If I manually jog Y I can move the axis more than 17" into a hard stop. Is there a parameter that is possibly set wrong or am I looking at a hardware issue?

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[Turbo442]

I noticed my 2005 VF2 is allowing me to exceed the normal limits of travel. 30" x, 17" y, 20" z. Homing the machine everything zeros correctly. X to the left, Y to the front and Z up. If I manually jog Y I can move the axis more than 17" into a hard stop. Is there a parameter that is possibly set wrong or am I looking at a hardware issue?

So I was just messing around and it seems like my original description of the issue is wrong. I just checked my Y travel and it was hitting an obstruction at 16.5". (Table all the way back). Very close to the end of its travel. There appears to be no visible obstructions. The way covers don't appear to be binding. Anything I should check first?


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[Tlarson]

Your grid offset might be off, causing the machine not to go to its true home, when you zero return it was is your actual distance to go on the control?

[HFO Tech]

What model is this machine? Is it a YT,SS, or just a regular VF2? What software versoin do you have in this machine? Depending on the software version you can go into the alarm history and see if any parameters have been changed. Also depending on the model version of the machine YT,SS changes what type of ball screw is in your machine. Has this ball screw been changed? Depending on your software version,ball screw pitch, motor type/encoder type will determine whether what the value is set correctly for your max travel for the machines ball screw/motor parameters. Do you have a sigma 1 motor? Although to answer your question, yes there is a max travel parameters for your ball screws. If something was wrong with your home switches the machine would either move in the opposite direction when it tries to home or it'll trigger home before it actually gets to home. Has your home switch position physically moved half an inch? Do you have a copy of your original parameters on a flash drive in the control cabinet or a Haas red binder looking book behind the operator pendant. If you do you can see what values this machine originally had in it when it was built. Lastly was this machine wrecked/serviced by anybody?

[Turbo442]

Your grid offset might be off, causing the machine not to go to its true home, when you zero return it was is your actual distance to go on the control?

when I zero return the machine the actual distance reads 0, 0, 0 to go. see the video below.

Thanks for the reply Tlarson!

[Turbo442]

Here is a Youtube video I made of the issue.

What model is this machine? Is it a YT,SS, or just a regular VF2?

2004 VF2D

What software versoin do you have in this machine?

From the boot up screen:
VER M13.07F
MOCON 12.05
04-11-12
MODEL: VF2D

Has this ball screw been changed?

I do not know, I am not the original owner. I have not changed the ball screw. If I were to take a wild guess I would say no.

Do you have a sigma 1 motor?

Sorry I dont know the answer to that yet. I believe Yaskawa makes the servo motors on this machine.

If something was wrong with your home switches the machine would either move in the opposite direction when it tries to home or it'll trigger home before it actually gets to home. Has your home switch position physically moved half an inch?

I pulled the front and rear Y axis way covers per the 2004 Haas VF service manual as you can see in the video. I did find a few chips laying on top of the home flag. I cleaned that up hoping that was the issue, nope. It appears the home flag is functioning correctly. In the video you will see the machine run into the Y axis limit switch and then back off about 1/2 an inch. I believe thats how its suppose to work. I assume the home flag and limit switch are the same sensor? The led is always on unless the flag is triggered. When the flag is triggered, the LED goes out. If I trigger the sensor with a screwdriver I get an over travel alarm as expected. I agree it kind of acts like the home flag has been moved. I can take a close look at it and see if there is any evidence of this. From my observations it appears I should have enough travel in the front way covers to accommodate a 1/2" Y axis home flag change. Since I am VERY new to Haas machines I am trying to take my time troubleshooting this issue. I dont want to blow up my way covers. (it seems weird to call them way covers but thats what the manual calls them). Maybe the previous owner moved the home flag due to some setup or vise clearance issue? Kind of sounds like a shot in the dark. If I am running up against the rubber bumper and my DRO is spot on it really cant be much else. (other than a weird ball screw like you say) I always like to go after the simple possibilities first.

Do you have a copy of your original parameters on a flash drive in the control cabinet or a Haas red binder looking book behind the operator pendant. If you do you can see what values this machine originally had in it when it was built.

Yes, I have all of the original parameters in the red binder. I have the original floppy and I have made a backup of the parameters on a USB. Is there any set of parameters in particular I should look at?
Here is a video I made of the parameter settings. I went through the screens quickly but you can pause the video if you need to.

Lastly was this machine wrecked/serviced by anybody?

Ha, I have not bumped it yet. I wouldnt be too surprised if something happened in a previous life. I have been doing all the service on it so far.

Last but not least...Thanks so much HFO Tech for taking the time to give a detailed reply! It really helps!

[Turbo442]

Here are some photos of the y axis home flag. (I hope thats what it is!)
There is no real adjustment range there. I am thinking the home flag might not be the issue.

[Turbo442]

From the manual:

X, Y, AND Z LIMIT SWITCHES Prior to performing an POWER UP/RESTART or an AUTO ALL AXES operation, there are no travel limits. Thus, you can jog into the hard stops in either direction for X, Y, or Z. After a ZERO RETURN has been performed, the travel limits will operate unless an axis hits the limit switch. When the limit switch is hit, the zero returned condition is reset and an AUTO ALL AXES must be done again. This is to ensure that if you hit the limit switch, you can still move the servo back away from it.
The limit switches are normally closed. When a search for zero operation is being performed, the X, Y, and Z axes will move towards the limit switch unless it is already active (open); then they will move away from the switch until it closes again; then they will continue to move until the encoder Z channel is found. This position is machine zero.
Auto search for zero in the Z-axis is followed by a rapid move from the limit switch position down to the tool change position. This makes the Z-axis a little different from the other axes. The position found with the limit switch is not machine zero but is the position used to pull tools out of the spindle. Machine zero for Z is below this by Parameter 64. Be careful during the Z zero search and stay clear of that rapid move.
What Can Go Wrong With Limit Switches? If the machine is operated without connector P5, a LOW LUBE and DOOR OPEN alarm will be generated. In addition, the Home search will not stop at the limit switch and will instead run into the physical stops on each axis.
If the switch is damaged and permanently open, the zero search for that axis will move in the negative direction at about 0.5 in/min until it reaches the physical travel stops at the opposite end of travel.
If the switch is damaged and permanently closed, the zero search for that axis will move at about 10 in/min in the positive direction until it reaches the physical stops.
If the switch opens or a wire breaks after the zero search completes, an alarm is generated, the servos are turned off, and all motion stops. The control will operate as though the zero search was never performed. The RESET can be used to turn servos on but you can jog that axis only slowly.

[Turbo442]

OK
I think I am getting closer.

I found a difference in the Y max travel steps (red book vs current parameter)
I need to go to bed, but thats probably it right?





Anyone know why these would change? Maybe a battery backup recovery?

[Turbo442]

OK that was it. Reverting back to the original red book Y MAX TRAVEL (STEPS) fixed it!!!!!!
No more hitting the hard stop. My max travel is around 16.1" in Y.

As a side note. One MIGHT be able to squeeze 17" if you moved the home flag a bit and opened up the max Y travel. Im ok with 16"

My Z max travel was off as well. X was fine.

[haastec]

Sounds like someone at the machine's previous home was trying to squeeze a part into the machine limits and opened them up .

Glad you got it sorted out.

[HFO Tech]

You're welcome Turbo