Hardinge CHNC turret setup



I have a CHNC that I'm thinking of converting. It's been done using Linuxcnc. But wonder if the Masso control might be easier and faster.

The CHNC turret has a 4 bit output. It requires controlling 3 relays to drive the turret.

The operating sequence would be:

Command turret change

the first relay opens a valve and pushes the turret up to disengage from the location keys.

the second relay opens and supplies air to an air motor to rotate the turret (1st relay still open)

The second relay is closed stopping the motor

the third relay activates a stop that prevents the turret from moving past it's position.

the third relay is closed withdrawing the stop.

The first relay reverses and pulls the turret down into engagement with the location keys.

So how do you control the relays, and how do you control the sequence they operate in? Is there a ladder or code that needs to be edited?

Or do you have turret code that can be edited to work?

Pretty good video showing a CHNC turret in operation



This a better explanation of the turret sequence

Rear air valve is actuated, check valve is defeated, turret lifts up, pilot valve is actuated, air motor spins, encoder sends position, control actuates stop valve, piston kicks out pawl and pressurizes stop cushion, ratchet engages pawl, bottom stop cushion, Rear air valve is released, pilot valve releases, turret drops down, check valve is set, stop valve is released, piston pulls in, pressure is released on stop cushion, and pawl retracts.

That's the mechanical explanation, for the actual electrical interface it's much simpler.

Turret encoder always reports a position. Between stations the encoder will report 0, no position for a small time, then the next station. The encoder output is binary coded decimal, which is just a fancy way of saying that station 1 is 0001 and station 8 is 1000 in binary, a straightforward conversion.

So, the control knows what station you are on and what station you want. It actuates the lift/rotate solenoid until it sees the station it wants to stop on, then it actuates the stop solenoid. If the turret has stopped rotating, it deactivates both solenoids and the turret drops down and locks. The solenoid signals are overlapping; the air motor *is* pushing against the stop pawl.

So, activate solenoid 1, wait for station, activate solenoid 2, if station doesn't change, deactivate both solenoids and look for the turret locked signal.


Thanks for the reply.

I don't see anything in the documentation on how to control the order of the relays for the solenoids. How is this done?


Page 309 of the manual shows 4 TC outputs. There should be a way of ordering the operation of these inputs.

For instance when you command a TC. 2 relays will be used in sequence. When the sensor gets to the appropriate TC position sensor, it then accuates a 3rd relay is actuated, then the 2nd and3rd are deactivated, and the 1st reversed.

I assume there must be a page not shown in the documentation that allows a user to create this configuration? Or is that created by Masso? If it's created by Masso then it may be unique to operating Hardinge CHNC lathes. I have an old Mori-seiki SL3 that would be much easier to operate. i.e activate relay to push turret out. activate relay to turn turret motor. when it gets to target position, turn off motor relay. pull turret back in simples.