lathe turret conversion help please

[chessie]

i need some help
i have a denford cyclone lathe. it was originally running on mach3. a few years ago i converted it to centroid acorn. it had a baruffaldi TOE80 8 tool turret but i didnt fit it i just put a dixon type tool post on it.

i would like to fit this on the lathe now if possible.
the encoder is missing off the turret i used a proximity switch before picking up on 8 bolts on a disc ,and its now powered by a stepper motor.

So going forward , can i use this with acorn lathe ?

are there any cheap encoders that will do the job available if so what do i need to buy.
Can i use the stepper motor or do i have to look for a 24v dc motor of some type.

the operation of this turret is as follows
call for tool
motor rotates
just before the correct tool is achieved a solenoid is actuated locking the pawl with a pin. The motor stops just past tool position
motor reverses when locked a proximity switch goes live. power to motor and solenoid stop .

any help would be appreciated
cheers steve

[Muzzer]

Wow - I hadn't realised there was such a great site for Denfordians!
https://www.denfordata.com/bb/viewforum.php?f=33
I could get lost in there for hours......

[Chaz]

You will need to do some custom ATC M6 code. If the sensors are PNP then you either need to get Eth1616 card or find a way to convert them to NPN as Acorn cannot read PNP.

[chessie]

changing the sensor to npn is not a problem i have a drawer full of them. i couldnt find anything on the denford site where someone is running centroid with the turret

[martyscncgarage]

I think the turret should have been left alone including its encoder...I discovered that myself with my Emcoturn 140. The little 3 phase motors was an elegant solution. Though my Emcoturn 140 goes slightly past the tool, when the control sees the tool number called stops and reverses my stepper motor and parks the turret against the stop. The stepper motor which operates AS a FWD/REV motor stays energized until the next tool is called. The stepper is NOT relied upon to hold the turret. The pawl is locked in a pocket....

Are you operating the stepper motor as a MOTOR?
Is there any video of the original turret working?
So you are basically counting tools. Do you have a proximity sensor on tool 1 to set a home position?
How does the turret stop? Once the control sees the called tool does the turret roll back against the stop? If a shot pin engages the turret, what allows the stepper motor to deenergize in order to let the turret loose to allow the shot pin to lock the turret?

What is left on the turret that is original?

Need to clearly and step by step tell us exactly how the turret works (or you expect it to work)

Marty

[suntravel]

IMHO for the original function you have to use the original encoder from baruffaldi.

It is one with 4bit Gray Code, parity and strobe signals, so it will use 6 inputs on the Acorn board.

Acorn can read the current tool position with the Gray code.

Uwe

[chessie]

thanks
the turret couldn't be left standard as i dont have 415v 3ph supply for the motor( i was told it couldn't be run 22ov3ph im in the uk) and the encoder was damaged.
i cannot find the videos i took of it operating in mach3.

the stepper motor isn't energised as in pushing against the locking pawl during machining it just stops in place


Basic operation

call for tool x
move to toolchange position
calculate no. of degrees per tool difference (n x 45deg) plus overtravel after pin 60deg
stepper would start cw
at correct tool position output shoots out the locking pin. motor overruns 60deg pulling out the pawl
motor stops
motor reverses 60deg locking the pawl
pin de energised so retracts
motor stops
a proximity switch checks to see if pawl is in locking position
if good announce new tool

ive attached original macro for mach3

So going forward i need to know how to use this turret on acorn
ideally using the stepper motor if possible
if i need to fit an encoder of some type to identify tool position thats ok, which type do i need and ill make it fit ?

i dont have a clue on macros for centroid. in mach it had an m6start file you could modify, is it similar in centroid

is there any help for writing a macro if that is what is needed.

any help appreciated steve

[Chaz]

Ive got an Emco 320 which (there is a thread about it here) I burnt out the AC motor for the turret. Ive since put on a Servo motor and I have done the same where I basically reverse engineer the steps it needs to take for each tool position.

My tool change logic is almost identical to yours and therefore could be modified easily once the basic macro is understood.

I'd be happy to share the code with you. Its not elegant, but its functional. A challenge I have is 'resetting' the axis / turret if there is a failure or power off but Ive solved this in my case by 2 options which I can explain.

I'm also in the UK, so happy to jump on a WhatsApp call to explain and show you what Ive done.