how works a Hydraulic turret?

Hello,

I got an okuma lathe for the price of the iron and I think to start a project to retrofit it with linuxcnc.

This lathe has a Hydraulic unit and valves for tailstock, chuck and turret.

Now I'm asking myself how the hydraulik turret ist controlled?
Is there a kind of feedback, so that the controller knows when the next tool is in place?

I have no clou, and I think it's better to ask first here befor disassembling the entire turret to see how it works.

Must hydraulic turrets clamp against a special coupling (for example curvic coupling). This is what maintains the turret always in the same position while clamped.
When the turret is unclamped it should rotate easy so that the motor that moves it can do it fast.

Regarding the feedback it can be mad on several ways, depending on the technology available at the time of construction.
It can be absolute encoder and the turret is moved by a servo (the machine knows the actual position from the encoder only); it can be a incremental servo and you need to know the current position before tool change, normally by some sensor(s) that identifys the current position.

You also have a sensor that informs that the turret is currently locked or unlocked (clamped / unclamped).

What okuma do you have? I have 2 and dismounted both turrets.

Nice to find someone who has an okuma lathe too.

The lathe I got is a LB9 from 1991. The Iron part seems to be in good condition, just a bit of rust on non important parts.
Only thing missing on the machine is the mainspindle motor and it's VFD.
The electronic part I think has no chance to get relived, so I plan to replace it completely.

Right now I'm figuring out how all the actuators work.
I need to understand that in detail in order to plan the retrofit.

If I understand you right, what you say is, the hydraulic part of the turret is just to clamp it in position, but the movement itself is made by a motor?
If it is like that, great, that will be easy to control, but where is that motor located? Inside the big socket of the turret?
Outside I see only the big servomotor on the back, that drives the Y axis, or am I wrong?

Another question regarding the servomotors vor X and Y Axis of that lathe.
What kind of servomotors are that, AC? DC? What kind of feedback comes from that servos?

If you like I can do some pictures to identify things easier.
I really, really appreciate your help.

jgnoss wrote:

Nice to find someone who has an okuma lathe too.

The lathe I got is a LB9 from 1991. The Iron part seems to be in good condition, just a bit of rust on non important parts.
Only thing missing on the machine is the mainspindle motor and it's VFD.

If you had them, probably you could not use them, so, if you just have the head stock you are ok. Currently is fairly easy to get a decent VFD and a suitable motor.

jgnoss wrote:

The electronic part I think has no chance to get relived, so I plan to replace it completely.

Same with me. You can check a thread that I opened some time ago and in one of the last posts it shows the machine naked. We made some more work on it, but we were expecting hardware, so it is taking more time than expected.

jgnoss wrote:

Right now I'm figuring out how all the actuators work.
I need to understand that in detail in order to plan the retrofit.

That is something that you must test and check yourself. I have a machine from 96 and one from 2003.

jgnoss wrote:

If I understand you right, what you say is, the hydraulic part of the turret is just to clamp it in position, but the movement itself is made by a motor?

Must like it. In my case yes.
There are machine that have a hydraulic motor insted of electrical. That is fairly easy to check, just count the number of hydraulic tubes that go into the back of the turret - or open the cover - you need to start cleaning something!

jgnoss wrote:

If it is like that, great, that will be easy to control, but where is that motor located? Inside the big socket of the turret?
Outside I see only the big servomotor on the back, that drives the Y axis, or am I wrong?

It is located on the back of the turret.
The big servo on the back... depends on what you call the back, but probably you are refering to the X axis or the Z axis. Y axis is not common on lathes, especially in 1991.

jgnoss wrote:

Another question regarding the servomotors vor X and Y Axis of that lathe.
What kind of servomotors are that, AC? DC? What kind of feedback comes from that servos?

If you like I can do some pictures to identify things easier.
I really, really appreciate your help.

This is important before a retrofit. My machine have absolute encoders, that I took of and installed incremental encoders with the objective to reuse the servos. As I am still waiting for the servo drives, I cannot state that they will work ok.
If you check the plate on the motor it should inform what type of motors they are.
If you need to buy new motors, I would check its price before they could put in danger the total cost of your retrofit (one of my motors are 4Kw that is really expensive - I do not know your machine)