Re: Tree Mill Help

[Enrique Sanchez Vela <enrique_sanchez_vela-at-yahoo.com>]

Hello folks,

 just wanted to thank you all for the help you have provided, I am sure
you would lend me a digital camera if we were close by to post the
pictures as they have been required.

  the machine isnt moving yet but at least I am having a good degree of
certainty that we can make it work. Gene helped me identifying the
required signals, now I have been able to test the servos and the
encoders (yes it has encoders not resolvers) will be next.

 will keep you posted.

thanks,
esv.

--- Gene Warren <gwarren-at-execpc.com> wrote:
> 
> Hi Enrique,
> 
> Enrique Sanchez Vela wrote:
> 
> >   I got a stgII card and it turns out that I dont really need it,
> well,
> > I got it and the mill has servo motors, so I dont have to replace
> them,
> > I guess I would need a driver card to interface the STGII with the
> > servos, anyone knows of a good, reliable and not very expensive
> card
> > that works with A/C servos.
> 
>      Look no further.  The Servo To Go card is the driver card you
> want.
> It produces plus or minus 10 volts.  0 volts for no speed, plus or
> minus 10
> volts maximum speed, depending on direction.  The Getty N360 sums
> your
> velocity command (from the Servo To Go card) with the Tachometer
> feedback
> (from your tachometer).  The difference between those two voltages is
> what
> ultimately controls the speed of your DC motor.  This is open loop as
> far
> as the Servo To Go card is concerned at this point.  The Getty N360
> is
> first adjusted with the offset pot, with zero volts input, for no
> motor
> movement.  Next, the Getty is adjusted to match the tachometer output
> voltage (3 volts per thousand RPM).  Third,  it is adjusted for your
> input
> scaling, which would be the 10 volt maximum output of the Servo to Go
> card,
> for maximum speed.  Now you are finished with the Gettys Drive.  You
> have
> just done the Velocity Feedback.  I usually do this with a battery
> box I
> made using a 9 volt battery.  (Gets me close and I don't need the
> controller.)
> 
>      Next, you hook up your encoder to the Servo To Go card and start
> adjusting the P.I.D. settings in the software.  These adjustments are
> considered, among other things, the Position Feedback.  The Getty
> N360 does
> not have P.I.D. adjustments.  I do not have a clue about these EMC
> adjustments because I don't have a Servo To Go card. but I'm sure
> someone
> here will help you. I might be able to help you with the P.I.D.
> theory.  I
> have a BDI v.2.04 EMC box with nothing attached to it yet.
> 
> >
> >  the servos are from GOULD and rated at 12.5 amp, in the mill there
> are
> > power drivers GETTYS 360, Three phase halfwave controllers., 240
> VAC
> > and 12.5A Rated Motor Current.
> 
>       We (me) will need a little bit more information about your Tree
> Mill.
> 
> 1.  What is the volts per thousand of your tachometers?  That
> information
> is usually printed or engraved somewhere on the tachs.  The tachs may
> be
> integrated with the motors.
> 
> 2.  Do you presently have Encoder feedback or Resolver feedback?  If
> you
> can't tell, post the numbers here and you will receive an answer. 
> (Posting
> all numbers here will be helpful, no matter how distant they may
> seem.)  I
> am going to guess by the age of your machine (20 years old) that they
> are
> resolvers.  If they are resolvers, you will have to include Encoders
> in
> your limited budget.
> 
> 3.  What is the model number of the Tree Mill?  Does 2UVR-C appear
> anywhere?  On the back of the column on that little door?
> 
> 4.  How many Getty drive packages are there?  Two?  I believe your
> Spindle
> motor is one or two fixed speeds at the most and the Z-axis is not
> controlled by encoder or any position feedback.  If this Tree is
> anything
> like the ones I have seen it is a flat milling machine, with preset
> drilling  done by a depth-stop micrometer.  The quill comes down,
> hits a
> mechanical stop, and a clutch slips to hold it there.  I would have
> to go
> to our Tool Room to check this out.  (We have well over 150 CNC
> machines in
> our manufacturing facility, and I don't have them all in my head.) 
> Get all
> the numbers from the Spindle motor.
> 
>      I believe we could make this Tree Mill Retrofit a group effort. 
> I
> have a lot of experience repairing machine tool electronics and doing
> drive
> setups (Servos), but no experience and less knowledge with EMC.  I
> have
> been reading this list over a year and I recognize lots of expertise
> here.
> 
>      A number of assumptions have been made here.
> 
> 1.  You have Gettys N360, 3 phase, half wave controllers. (Might be
> called
> a RN136 somewhere.)
>      Note:  this has since been confirmed.
> 2.  You have a 2UVR-C Journeyman Tree Mill machine.
> 3.  The present controller has a keypad on the upper left of the
> pendent
> that looks like a touch telephone keypad.  If you want, I can send
> you a
> JPG picture of the one we tossed out when I retrofitted it to an
> Allen
> Bradley 8400 in the late 80's.
> 
>      If the above is true, I can send you spare manuals of all three
> items.  Item 3 would be the Operators manual.  (I am an unrepentant
> pack
> rat.)  Email your Snail mail address to me privately if you want any
> of
> this.  No cost.
> 
> Later,
> 
> Gene
> 
> 


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