Re: Moog Hydrapoint

Hi Jon,

Some good points here. I was unaware of the hydraulic problems you
mention. Good thing to consider because the machine is resident in
my garage.

The Moog doesn't use servo valves (although I really don't know what
you mean by servo valve - I'm assuming something electrically
driven). What it uses are hydraulic cylinders to provide the motion
with air driven logic. There are a series of holes .1 apart along
the length of the axis and a rotary device with 100 holes and the end
(to give .001) all driven by air.

The machine has hydraulic cylinders but there are cover plates
exactly where the handwheels go on a regular bridgeport. The table
castings all look the same as a regular bridgeport. I assuming that
ballscrews can be fitted in the same manner as a normal bridgport.

Thanks

Gary

--- In CAD_CAM_EDM_DRO@y..., Jon Elson <elson@p...> wrote:
> stirlinguy wrote:
>
> > Hi,
> >
> > I have acquired a Moog Hydrapoint (full hydraulic Bridgeport with
> > tape reader) NC mill and am pondering the possibilities for CNC
> > control.
> >
> > I know some people have ditched the hydraulics and gone with ball
> > screws and servos. That seems like the most straightforward
approach
> > (to my mind, anyway). But, I was thinking that if the machine can
> > already read tapes that setting up a computer to send signals
> > emulating the tape could be done. Any thoughts?
>
> It depends. Apparently, the Cincinnatti hydro-tel (I think that's
what
> they called it) had a totally hydraulic/pneumatic control, with a
hydraulic
> velocity DAC with a series of holes graduated in 1:2:4:8:16:32 etc.
> areas. Not a good candidate for electronic upgrade.
>
> No doubt the Moog has Moog proportional servo valves, which are
> the industry standard. If they are in good condition, you can
drive them
> with linear signals from a velocity error amp, essentially a servo
amp,
> but the power amplification is done in the servo valve.
>
> You should know that hydraulically-operated machines consume
> HUGE amounts of power, require people 30 feet away to use ear
> protection, often require water cooling of the hydraulic pump, wear
> out VERY expensive hoses frequently, and are a general pain in
> the rear. Also, if a high-pressure hose bursts while you are
> nearby, the results can be FATAL! Pinhole leaks at 1500 PSI
> can inject oil under the skin, causing an elioma (I think I spelled
> that right) which can cause permanent disfiguration even after
> surgery. Unless you will keep the machine in tip-top condition,
> I would STRONGLY suggest you do NOT keep the hydraulics.
> This is not a place for deferred maintenance.
>
> > My reasoning for this is that the machine already knows how to
move
> > x, y, and z through the hydraulics, so why not use that
> > functionality? (And save some cash!)
>
> If this machine uses ballscrews and hydraulic motors, it would be
MUCH
> better to replace the hydraulic motors with servo motors.
>
> If it uses cylinders to move the table, then a ballscrew conversion
> would be a substantial expense. I would still go that way, rather
> than messing with the hydraulics.
>
> Jon