Re: [CAD_CAM_EDM_DRO] Encoder on spindle question

On 07/26/2011 02:32 PM, Ron Thompson wrote:

> If I use the index, Mach never sees it. If I use either channel, the
> index light (on the diagnostics page of Mach3 turn) will pulse slowly.
>
> The spindle speed dro stays at 0. Do I need to turn it on somewhere?
>
> I am guessing the pulse width is too narrow for mach to read. My
> thoughts for a cure are to add a couple of decade counter chips to
> divide by 40 or so.
>
> I'd like to use the existing encoder, but as a last resort I will remove
> it and install a SB5B to give one pulse per rev.
>
> Thanks for any help!

To find out if it is a pulse width problem, you may need to add a "one
shot", but, as I understand it, Mach relies on 1 PulsePerTurn encoder
operation for threading, otherwise there is no way to be sure that the
thread starts in the same place.

Adding a counter won't help, it will still not set the phase of the
index pulse. Add a single pulse per turn encoder and it MAY work, but
for it to work either the spindle must be a closed loop system (for
constant speed) or be massive (so it doesn't change speed as the tool
contacts the work.)

Dave 8{)