Re: Surface grinder feed project

--- In CAD_CAM_EDM_DRO@y..., "sleyed" <Sleyed@a...> wrote:

>
>
> I have a manual 6x18 surface that I would love to add feed
> controls to. I have been collecting misc parts in anticipation for
>a
> one of these days projects. What ever is in the back of my mind
>while
> rummaging through a friends scrap yard.
> So far I have a servo and a servo amp that could possibly be
>mounted
> to drive the now manual handle. I ain't so sure for/rev on a non-
>stop
> basis is such a good plan considering the loads vs motor size etc.
>No
> plan as yet on how to utilize a simple circuit to drive the amp
> inputs either.
>
> I know hydraulics would be the simplest solution, but as of yet
>have
> not found a suitable cylinder with double rods and an 18" stroke
>for
> a reasonable price. The servo could still be for the Y-axiz move
> after each pass of the X.
>
> Anyone else in a similar quandry?
>
> Doug

I converted one a few years ago by using a rodless air cylinder, 2
end of travel valves and a 5/2 valve for the X and a simple ratchet
arangement copied off a shaper for the Y. Worked fine right up until
I sold the machine.
The end of travel valves have 3 pipes going to them.
One main feed from the 5/2, one small supply pipe and a small trigger
pipe that goes back to the sense port on the 5/2.
How it works is, you switch air on and it move in whatever direction
the 5/2 is set. At the end of the travel the end of travel valve
senses the build up of pressure and the trigger fires a burst of air
to shuttle the 5/2 to go the other way. Same thing happens at the
other end.
It's just an air flip flop circuit but it's simple and cheap.
Just set the travel stops for wherever you need them, it doesn't have
to go full strok. It sensors the end point.

John S.