Remove Z axis servo -- coupler question

[miyano_cnc]

Hi,

I need to remove a Fanuc Z axis servo from my mill so that it can fit into my garage and I have some questions:
- do I just need to loosen the set screw in the picture below and pull the entire coupler off the ballscrew with the servo? (I didn't see any set screws on the top red section)
- or do I need to take apart the coupler with the 4 sets of studs / nuts (99.99% sure this isn't the path as I can't get a closed wrench on the nuts)


Thanks

 

[Ox]

Take the 4 through-bolts out.
Mark which upper hole goes with which lower hole (paint or marker) and it will be spot on when you put it back together, even if either spins before you re-assemble.


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Think Snow Eh!
Ox

 

[GENERALDISARRAY]

make sure the head is blocked if the motor has a brake.

 

[LocherInc]

You can do it either way. Personally, I like to leave the coupler assembled as a unit and pull the motor. Easier to reassemble than trying to tighten those bolts up. Sometimes there will be 2 set screws 90 degrees apart to remove. Then you can use a small pry bar to help slide the coupling off if needed.

 

[miyano_cnc]

Take the 4 through-bolts out.
Mark which upper hole goes with which lower hole (paint or marker) and it will be spot on when you put it back together, even if either spins before you re-assemble.

Okay, if I do this will the washers (black) above and below the circular ring (silver) that goes through all 4 bolts come apart? Or are the washers and the silver ring 1 piece?

make sure the head is blocked if the motor has a brake.

Yup, got that ready under the spindle for when I take out the servo. Thanks for the info.

You can do it either way. Personally, I like to leave the coupler assembled as a unit and pull the motor. Easier to reassemble than trying to tighten those bolts up. Sometimes there will be 2 set screws 90 degrees apart to remove. Then you can use a small pry bar to help slide the coupling off if needed.

Good to know, I used this method on my smaller hobby mills and would prefer to use on this machine to take the coupler out as one piece. The access to it is horrendous. I will bring a better light to make sure I see the coupler/set screws better next time.

 

[Ox]

The flanges are opposites.
On two of them there is a small bolt hole above for just the bolt, with a larger hole below for a bushing.
Then the other two holes are the other way.
If you doo it this way - you will not have to adjust your Z HOME position, and there is always a chance of your HOME point on your encoder being too close to your HOME limit switch point, that you could get a full rotation difference when you home the machine. Not likely, but can happen.

So - even if you take it apart, and you have your holes marked, you can spin the motor shaft 'till Tuesday and it won't matter, it will still be dead nuts like it was before you took it apart.


If you must take the cinch loose on the motor shaft, then try to mark that as best as possible, like paint (Dykemm?) and then a scribe mark, and that will likely be good enough for who it's for.


You just don't want to take it apart willy nilly and then haft'a dink with tool change height and whatnot later.


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Think Snow Eh!
Ox

 

[miyano_cnc]

If you doo it this way - you will not have to adjust your Z HOME position, and there is always a chance of your HOME point on your encoder being too close to your HOME limit switch point, that you could get a full rotation difference when you home the machine. Not likely, but can happen

Does this apply only to servos with absolute encoders? Or to servos with relative encoders as well?

 

[Ox]

Well, I am actually replying with what you refer to as a relative encoder I guess.
One where you are HOMING the machine each day, and it looks for a HOME pulse on the encoder.

Now if you don't have that, then I guess the next question is - can you remove the motor w/o unhooking the encoder cable - AND make dead sure that the motor shaft doesn't turn during the move? (Maybe just duct tape it so that it can't turn?)

But if you have "absolute" encoders, and you will not be able to make the move w/o unhooking the cable, then you can doo it any which'a way that you want as you will have to set your Z zero point after you git it back together anyway.

Good points to ask as I didn't consider the other option.


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Think Snow Eh!
Ox

 

[miyano_cnc]

Well, I am actually replying with what you refer to as a relative encoder I guess.
One where you are HOMING the machine each day, and it looks for a HOME pulse on the encoder.

Okay, I have this type of a servo/encoder. I forgot about the home pulse output.

 

[SteveEx30]

Make your life easier and don't unhook the electrical cables. Should have plenty of slack to swing the servo down. I would undo the 4 bolts as OX suggested, comes apart easier. But up to you. I've moved several machines under low doors and had to do this.

Also once you power on, replace any batteries !