rotary axis
Moderator: Harold_V
rotary axis
Hi
Does the fourth or fifth axis have reference point?
Does the rotary axis need go to reference point when turn on the cnc machine?
Thank you
Does the fourth or fifth axis have reference point?
Does the rotary axis need go to reference point when turn on the cnc machine?
Thank you
- Mid Day Machining
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Re: rotary axis
Yes it does. Otherwise it doesn't know where it is. It's just like the X,Y and Z axis. If you don't home them, they don't know where they are.
You can buy good parts, or you can buy cheap parts, but you can't buy good cheap parts.
- Bill Shields
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Re: rotary axis
unless you are using an absolute encoder
Too many things going on to bother listing them.
- Mid Day Machining
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Re: rotary axis
If you don't reference the axis, how does it know where it is?Bill Shields wrote:unless you are using an absolute encoder
You can buy good parts, or you can buy cheap parts, but you can't buy good cheap parts.
- Bill Shields
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Re: rotary axis
that is why it is called an ABSOLUTE encoder.
It always wakes up smart, knowing exactly where it is relative to reference zero.
Honest....
It always wakes up smart, knowing exactly where it is relative to reference zero.
Honest....
Too many things going on to bother listing them.
Re: rotary axis
Well, kinda sorta. You zero your rotary out like you do all of your other axis as referenced to you rpart. It doesn't "require" a home limit, but you can incorporate one.Does the fourth or fifth axis have reference point?
Does the rotary axis need go to reference point when turn on the cnc machine?
Dean
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Re: rotary axis
The X, Y and Z axis have absolute encoders as well and they still need to be zeroed when you turn the machine on in the morning so they know where they are.
You can buy good parts, or you can buy cheap parts, but you can't buy good cheap parts.
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Re: rotary axis
Correct me if I'm wrong. I thought an absolute encoder knows where its own zero is (within one revolution). The machine must be brought home (to a limit switch type device) to within one encoder revolution of the machine home, then the encoder takes over to find it's own home and the machine control sets this to the axis home position. The Haas rotary axis I used worked the same. When I turned it on, it would look for it's home by rotating slowly. Whenever I powered up the rotary unit, it moved close to the home zero on the axis, the unit would advance slowly and stop when the axis was at it's true "home zero point" and the readout would register at 0.000. I didn't have a choice in this matter. The unit went through an automatic start up procedure before I could use it.
Bruce Mowbray
Springville & Southern RR
TMB Manufacturing & Locomotive Works
Springville & Southern RR
TMB Manufacturing & Locomotive Works
- Mid Day Machining
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Re: rotary axis
"EXACTLY". Otherwise, how does it know where it is. Once it has been sent to a HOME position, then you can lie to it and tell it a new zero position in your G54 work shift.Bruce_Mowbray wrote:Correct me if I'm wrong. I thought an absolute encoder knows where its own zero is (within one revolution). The machine must be brought home (to a limit switch type device) to within one encoder revolution of the machine home, then the encoder takes over to find it's own home and the machine control sets this to the axis home position. The Haas rotary axis I used worked the same. When I turned it on, it would look for it's home by rotating slowly. Whenever I powered up the rotary unit, it moved close to the home zero on the axis, the unit would advance slowly and stop when the axis was at it's true "home zero point" and the readout would register at 0.000. I didn't have a choice in this matter. The unit went through an automatic start up procedure before I could use it.
You can buy good parts, or you can buy cheap parts, but you can't buy good cheap parts.
- Bill Shields
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Re: rotary axis
you are both correct (as am I), but you are missing the big picture here.
for a tool changer, since the carousel only rotates 360 degrees (in this case), having an ABSOLUTE encoder on it that knows where it is relative to reference zero is all that is needed. No need to home on power up.
Capice?
for a tool changer, since the carousel only rotates 360 degrees (in this case), having an ABSOLUTE encoder on it that knows where it is relative to reference zero is all that is needed. No need to home on power up.
Capice?
Too many things going on to bother listing them.
Re: rotary axis
The OP posed the original questions:
Dean
and somehow got side tracked into tool changers.Does the fourth or fifth axis have reference point?
Does the rotary axis need go to reference point when turn on the cnc machine?
Correct! If you want to have repeatability the next time you turn your machine on, it must be 'homed'. I usually do one-offs and don't bother with homing my rotary.Bruce_Mowbray wrote:
Correct me if I'm wrong. I thought an absolute encoder knows where its own zero is (within one revolution). The machine must be brought home (to a limit switch type device) to within one encoder revolution of the machine home, then the encoder takes over to find it's own home and the machine control sets this to the axis home position. The Haas rotary axis I used worked the same. When I turned it on, it would look for it's home by rotating slowly. Whenever I powered up the rotary unit, it moved close to the home zero on the axis, the unit would advance slowly and stop when the axis was at it's true "home zero point" and the readout would register at 0.000. I didn't have a choice in this matter. The unit went through an automatic start up procedure before I could use it.
"EXACTLY". Otherwise, how does it know where it is. Once it has been sent to a HOME position, then you can lie to it and tell it a new zero position in your G54 work shift.
Dean
- Bill Shields
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Re: rotary axis
Sorry...same applies to the rotary axes:
If you are using a 4th or 5th axis and you are using ABSOLUTE ENCODERS, you do not need to home / reference.
The same is true if you are using linear ways with ABSOLUTE SCALES - just turn it on and go.
If you are using a 4th or 5th axis and you are using ABSOLUTE ENCODERS, you do not need to home / reference.
The same is true if you are using linear ways with ABSOLUTE SCALES - just turn it on and go.
Too many things going on to bother listing them.