Re: [CAD_CAM_EDM_DRO] Re: Re: Re: Electronic Lead Screw & Power Cross Feed | Poor Man''s CNC ?

John Stevenson wrote:

>>Vaso wrote:
>>
>>
>>
>>>Bob:
>>>
>>>You've done an excellent review of the entire issue. Full CNC is
>>>clearly far more complex than electronic lead screw - and requires far
>>>more learning time. CNC leads to a different lathe machine altogether
>>>- where "machining" is replaced by "programming" - even for simple
>>>one-off pieces. I understand - once converted to CNC - a "CNC lathe"
>>>cannot be a good "hands-on" manual lathe - except maybe with expensive
>>>electronic handwheels.
>>>
>>>
>>>
>>>
>>Not necessarily true. We have a Bridgeport/Romi CNC lathe at work that
>>can be used manually as if it only had a DRO. You might notice a slight
>>drag on the handwheels, that is about the only sign. I don't see why a
>>CNC setup that preserved the handwheels couldn't be used manually.
>>It would need either low-cog stepper motors or servos. If the servos
>>had feedback to the computer, then it could act as a DRO when not in
>>CNC mode.
>>
>>Jon
>>
>>
>
>Mach3 does just this. A seamless swap over from manaul to CNC with the displays acting as DRO's
>
>

With a number of limitations. For instance, the encoders can never
exceed about
30,000 counts a second or there is the possibility of lost counts, since
this is
a software-only encoder counter. And, of course, you need to have encoders
and servo motors to read the position at all.

Jon