lathe turret encoder help

[iamspuddy]

i have a barruffaldi toe80 and im fitting it to a cyclone running on centroid acorn .
it had no original motor or original encoder.
ive fitted a stepper motor but will change if not suitable .

i need help looking for a gray code encoder suitable for an 8 station turret that i can make something to fit it to the shaft to show actual position.

im open to a better way to get this to work on the lathe

any help appreciated

[m_c]

A stepper motor won't work on a TOE turret, as they need quite a bit of power to lock the turret.

Are you sure it's a TOE80?

[iamspuddy]

sorry i forgot to say i initially had it working with mach3 before i changed to acorn . the nema 34 reverses and pops out the locking pawl no problem . the macro counted steps between tools position then reversed a set amount after the locking pin was fired to pop out the pawl to lock in place . it counted by a proximity switch picking up 8 capscrew heads on a disc coupled to the shaft . i didnt know how to get it to work with centroid so i took it off and fitted a dixon style toolpost.

[m_c]

That doesn't sound like a TOE turret, as the TOE is more complex than a locking pawl.
Denford did fit a more basic ratchet type turret, which I think was their own design.

I'm not aware of any cheap grayscale encoders.
You could use an absolute rotary encoder (about £40 on Ali from a quick search), combined with a microcontroller capable of reading whatever output the encoder uses, that converts the absolute position into a more basic output, but that would involve some coding and circuit design.

You could stack 3 optical slot sensors that read suitable slotted discs to generate gray scale (or whatever combination of bits you'd like for each position).

However the simplest method would likely be a single home sensor, and run a turret homing macro when you power the lathe on.

[iamspuddy]

Thanks
Definitely a toe80 I may have used the wrong terminology to describe the action

[Lee Roberts]

@Spuddy

It’s good to hear you had it working under Mach3 using the proximity sensor and step counting setup. Sounds like you got it dialled in nicely, considering the usual headaches with turret logic. I agree with @m_c though, the TOE80 is a bit of a beast compared to some of the simpler pawl types, so hats off for getting that working on a NEMA 34!

Switching to Centroid definitely adds a layer of complexity but also opens things up long term, I like the idea of bringing in an absolute encoder + microcontroller to translate position states, might be overkill for now but definitely worth thinking about if you want to make it bulletproof down the line...

That said, the proximity + cap screw combo was clever, If you ever fancy building on that again, I reckon a better-quality proximity setup or magnetic encoder ring with discrete states for each turret position could give you what you need with minimal fuss, especially if it just has to tell Centroid “where it is” after boot.