Re: Re: Moog Hydrapoint

Gary (comments mixed in)

>    From: "stirlinguy" <Gary.Rose@...>
> Subject: Re: Moog Hydrapoint
>
>Currently, the y-axis has
> a cover plate that has four bolts holding it on.  It is in exactly
> the spot a handwheel would go, so I was hoping that this axis
> wouldn't be too bad.

On the ones that I have, this is a large rather deep tub that bolts to the
knee. It is where the stationary end of the hydraulic actuator sits. This
actuator is rather easy to remove. Take that cover off, loosen the bolts
holding the actuator. Slide the x way toward the actuator end and reach
under and you can get at the end of the y actuator that is connected to the
saddle. The x actuator is much worse. 'Course all this is a couple years
old now and that oldtimers stuff has set in.

> > I have some plans to make my own screws using the 5/8 rolled screws
>> from Thompson and spin the nuts rather than the screw.  There is all
>> kinds of room under there once you get the actuators out.  
>
> Do tell, why do you want to spin the nuts?  For this type of machine,
> I've only ever seen the screws spun.  What are the advantages?

I'm not sure what the wisdom of the group is but my thinking is that you will
reduce or eliminate the whipping on the long screw for the x axis if you spin
the nut rather than the screw. If I want about 150 ipm that means that I
will have to spin something in there about 750 rpm and I would think that you
would get some rather bad whipping when the x slide is near one end.

I still service a Hydrapoint that was converted to an MHP by Moog before this
part of the company went ... uh ... belly up. Even though these screws are
better than an inch diameter, the allignment of the screws, end mounts, and
nuts isn't perfect and you can hear several resonances of the screws as they
whip.

Some have suggested that compression and twisting is just as much a source of
error either way and that a larger screw will compress and twist less when
subjected to the motor or load torque. The conclusion that I came to based
on that discussion is that these will not be much of a factor with this size
of screw and machine.

> > I believe that there is one other fellow on the list who has one
>> that he is converting to run with the EMC.  I have some preliminary Tcl/Tk
>> code to operate the tool changer from an aux parport if you decide to use
>> the EMC
>
> Sounds great!  I currently do use EMC, I like it.  I'll have to bring
> this issue up again when I get closer to dealing with the toolchanger.

Fantastic. Before long we will have three of these converted and running the
EMC.

Ray