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Mori AL-2 Z return problem

triumph406

Diamond
Joined
Sep 14, 2008
Location
ca
So have a newly acquired Mori AL-2. When I went to see it the owner was able to home the machine in both X and Z.

Now I have the machine I can only home in X. It will not home in Z and when trying to home it goes past the Z axis prox switch and carries on to the soft limit switch.

When I look at the ladder, the ladder location for the Z axis shows it's already activated. The line 5.4 is always activated when the machine is turned on.

Now if I check continuity of the wires It's good all the the way to the first Honda connector.
From the Mori p/no for the prox switch it is a NO prox switch.
When I check across the terminals on the terminal strip immediately upstream of the switch I read 24V, so the switch is open. When I pass a steel plate under the switch it drops to 2V so the prox switch is working.
When I jump across the terminal strip, simulating the switch is closed, the ladder line 5.4 is not highlighted anymore.But it still will not home in Z

Not sure if this makes any sense

Any ideas?
 
IIRC, the soft overtravel on that machine and control is not a limit switch, but a parameter. There is a hard overtravel limit switch that triggers an e-stop condition. If you are hitting the soft overtravel alarm before it will reference try setting the parameter (5220 IIRC) for Z+ overtravel to 999999 (note the original value before changing). Then do a zero return. After successfully doing the zero return reset the parameter to the original value.
 
This is the Z-axis configuration.
Blue non-contact Z-return de-acelleration prox sensor, then the roller soft limit switch above.
Middle of image is the flag the prox sensor sees before slowing down to get to the next index on the servo encoder.


IMG_5794.JPG
 
I’m pretty sure the roller limit switch is only the hard overtravel. Press it with a screwdriver and see if the machine e-stops.

The roller works.

The problem is the prox switch. The Ladder shows it as closed even when the prox switch is a long way from the flag. But when homing it goes past the flag to the overtravel position.
So I can home in X but not Z
 
The roller works.

As in it e-stops?

The problem is the prox switch. The Ladder shows it as closed even when the prox switch is a long way from the flag. But when homing it goes past the flag to the overtravel position.
The X address for the prox input in Diagnostics or as an element on a ladder rung?

The typical method for a 10TF zero return is the axis moves, often at rapid, until the reference switch changes state. Then the axis slows and continues to move until the switch changes state again. The axis continues moving until the one revolution pulse of the encoder is read. At that time the axis stops and zero return is complete ( I'm ignoring reference counter and the grid shift for this explanation as it just confuses most folks).

When the prox is in front of the flag has its state changed from when it is away from the flag?
 
As in it e-stops?

yes

As in it e-stops?


The X address for the prox input in Diagnostics or as an element on a ladder rung?

The typical method for a 10TF zero return is the axis moves, often at rapid, until the reference switch changes state. Then the axis slows and continues to move until the switch changes state again. The axis continues moving until the one revolution pulse of the encoder is read. At that time the axis stops and zero return is complete ( I'm ignoring reference counter and the grid shift for this explanation as it just confuses most folks).

When the prox is in front of the flag has its state changed from when it is away from the flag?

The line in the ladder 5.4 is activated when the machine is turned on and the Z-axis is away from the flag. The state of 5.4 doesn't change even when the prox travels over the flag.
The only time the state changed is when I put a jumper across the prox switch.

The x-axis works fine. I can see the ladder line 5.5 change when the x-axis prox switch sees the flag, and just before the x-axis is homed, and the home light comes on
 
Prox dead after shipping? In the first post you said a meter check showed the prox was working. A bit confusing as now it sounds like you determined the prox is bad. Does 5.4 change if you put a piece of metal in front of the prox? If so, then you might be able to adjust the prox a bit closer to the flag and make it work.
 
Prox dead after shipping? In the first post you said a meter check showed the prox was working. A bit confusing as now it sounds like you determined the prox is bad. Does 5.4 change if you put a piece of metal in front of the prox? If so, then you might be able to adjust the prox a bit closer to the flag and make it work.

It eventually turned out to be the value in parameter 5220.

The axis wasn't getting too the index mark before the soft limit. So increasing the value of 5220 worked. Watching the x and z switches change state in diagnostics showed they were working, so next logical step was to assume the z axis was soft limiting too early

Not sure why this would be the case as I don't see the parameter changing, but that was the fix. Did find though that flag had to be very close to the prox sensor to work reliably.

-----------------------

Got to say not liking this 10T control.
 
In post 4 I outlined how to manipulate 5220 to allow you to complete a zero return. Now that you have gotten a good zero return, it is very likely that you can reset 5220 to its original value and all will be well.

The reason this trouble occurred is that the Z axis was not properly secured during transport and it moved.
 
Glad to see this all got figured out. What I have for info may be a little late to the party, as I bet you have the way covers bolted back up, but I'll share it anyway for future reference.
It's been my experience with two 90's Mori mills and a 2000 lathe that the travels and over travels are referenced as follows.

1) On machines with the orange/brown plastic bumpers on both ends of the ball screws, which for me has been every one, the specified machine travel in each axis equals the space between the two bumpers minus 10mm. In other words... run your ball nut flange or free end to 5mm from the bumper, and you're either at home or at full specified travel. If you look closely in your Parts Manual on the ball screw pages, you'll see this 5mm referenced. At least it is in my manuals.

2) The Soft Limits are then set by parameter 1mm past that position.

3) The Hard Over Travel plungers are then set as close to the soft limit as you're able to set them.

That's it.
 








 
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