Strippit Machine Servo-Drive Motors
The Strippit Company used   D.C. Brush-Type  Servo Motors  on all their  HECC80  CNC and  "A"  NC Control Turret Punch Machines Manufactured in the 1970's & 1980's.

This discussion will pertain Specifically to  Servo Motors that were used on Strippit Machines of this Era.     They are Typically Tagged as
Porter  /  Peerless  /  Magna  /  Machine Technologies   on the  Motor Name-Plate.

I Stock,  Here at  Machine Technologies,  All these Servo Motors,  and I Can Provide Motor Testing,  Rebuilt-Exchange Motors,  Rebuilding of Your Motors,  &  Repair Parts.
Later-on,  in 1986 on  FC1000/3's,  and in 1987 on the  FC1250/30/1500 Machines,
Strippit started Converting to   Fanuc  GN6 CNC Controls, 
which used  Fanuc's  Own  D.C. Servo Drives  &  Servo Motors.  

Around 1989,  Strippit Converted again to  Fanuc  OP Controls,
which used a Newer & Superior Motor Technology,  A.C. Servo Drives  &  A.C. Motors.   

A.C Servo-Motors  &  Motor-Drives  are Superior Technologies, 
But God Help You  if you Need to Replace one of these Fanuc Motors, 
because Fanuc often Quotes  Months Delivery  and  Costs  of  $10,000  to  $25,000!    

I Do Not Repair or Stock  Any  Fanuc Motors at this Time.
The Following are these  DC Servo Motor Types, 
and the Strippit  HECC80 Control  Turret Punch Machines  that they were Used On;
Strippit   #17539-000  
Model   #181-04-0020-0

Used on the  T-Axis  of  FC1000/1,  FC1000/2,  and  FC1250/30/1500 Machines with 20-Station Turrets.   But is Not used on 33-Station  FC1250/30/1500 Machines.

This Motor is the Same as  #17497-000 Motor,  Except it does Not have  Air Cooling Ports.   You can Substitute a  #17497-000  for a  #17539-000  on a
T-Axis,  but you can Not Substitute a #17539-000 for a  #17497-000 on a X-Axis because of the Lack of Cooling Ports.

Brushes & Caps are Same as #17497-000.
Strippit   #17497-000  
Model   #181-04-0011-0

Used on  X-Axis  on Strippit  FC750,  FC750/2,  FC1000/1,  FC1000/2  Machines.    Has a  1 1/2"  Pipe-Thread Cooling-Air Inlet Port at the Back of Motor,  Air goes through Motor and Out Slots at Bottom Front of Motor.

Uses  4  --  #17506-000  Brushes.   Most Motors use  3/4" Small-Disk Out-Side Thread Type Brush Caps,   But  Older Motor Versions use  Cup-Type Brush Cap with Inside Threads.
Strippit   #17360-000
Model   #181-12-0015-0

Used on  Y-Axis  of  FC750,  FC750/2,  FC1000/1,  FC1000/2,  FC1250/30/1500,  FC1250/30/1500 LaserTool,  FC1250/45, LaserCenter,  FC51/30,  FC51/40,
and  Blanking Center Machines.

Motors use  6  --  #17788-000  Brushes and  7/8" Disk Brush-Caps.
Strippit   #17538-000
Model   #181-12-0019-0

Used on   X-Axis  of  FC1250/30/1500,  FC1250/30/1500 LaserTool,  LaserCenter, FC1250/45,  Old Style FC1250/30,  FC51/30,  FC51/40  and
Blanking Center Machines.  

This is just a Shorter Version of the #17360-000  Motor.

Motors use  6  --  #17788-000  Brushes and  7/8" Disk Brush-Caps.
Strippit   #17510-000
Model   #183-18-0190-0

Used on the  T-Axis  of  FC1250/45,
Old-Style  FC51/30,   FC51/40,   and  FC1250/30   (NOT  FC1250/30/1500) Machines.  

Motors use  8  --  #17506-000  Brushes and  Special  Top-Hat Disk  or  the
Small  3/4" Brush-Caps.

This particular Motor is a  "Pull"  from a Machine I Scraped,  and still has it's Coupling & Special Geared Resolver Feedback Package attached.
Strippit   #19463-000
Model   #181-04-0034-0

Used on  T-Axis  of  FC1000/3  and   FC1250/30/1500  Machines with
33-Station Turrets.

Motors use  4  --  #19463-000 
"Type-C"  Brushes,   and have a
Steel Rectangle Brush-Cover.

Motor was also Sometimes used on
X-Axis  of  FC750 & FC750/2  and 
X & T  Axis of  FC1000/1  and  FC1000/2  Machines  in a  Mistaken Attempt at Increased Reliability.  They Work OK there,  but give No Added Benefit.

I now also use this Motor as a Substitution for the  #17497-000  and  #17539-000  so that I only have to Stock 1 Motor instead of 3.  This particular Motor is one that I Personally Rebuilt.
Strippit   #19399-000
Model   #191-04-0029-0

Used on  Y-Axis of  FC1000/3  Machines.

However,  with a Bit of Grinding for Mechanical Clearances,  it can be used as X-Axis Motor on FC1500/45 Machines.

Motors use  4  --  #19463-000  "Type-C" Brushes with
Steel Rectangle Brush-Covers.
Strippit   #19462-000
Model   #191-04-0033-0

Used  Only-On  the
X-Axis  of  FC1000/3  Machines.

Motors use  4  --  #19463-000  "Type-C" Brushes,  and have a
Steel Rectangle Brush-Cover.
#17506-000  "Small Brush"

.250" Thick x .500" Wide x .625" Long
The Round Plastic Brush Caps used on these Motors are Easily Chipped and Broken by
Careless Removal with a Screwdriver !!!   Make a Removal Tool from Thin Sheetmetal
Cut to the Width of each Caps Slot.    We Stock the Following Replacement Brush Caps.
Motor  Brushes  &  Caps

Motor Brushes should be Checked Regularly for Wear!   Replace Brushes if Worn to Half their New Length.   Check X & T Motor Brushes once a Year,  and check Y-Axis Brushes every 6-Months.   Check more often if these seem to be Wearing Rapidly.

I usually  "Tag"  Each Motor on Machine with It's Brush  "Inspection Date", 
or  else keep a Repair Maintenance Log Book with this Data Recorded in it.

If you Don't Check them,  Brushes will Wear Down until Carbon is Gone,
the Copper Wire & Steel-Spring Digs & Burns into the Commutator,  Ruining Motor.
#17788-000  "Large Brush"

.250" Thick x .750" Wide x .750" Long
"Type-C Brush"  for  FC1000/3  &  FC1500/45  Machines

.250" Thick x 1.000" Wide x .875" Long
"Small-Disk"  Type Brush-Cap  that are
used on Most Motors that use the
Small  #17506-000  Brush.

3/4"  Wide with  Outer-Diameter  Threads
"Small-Cup"  Type Brush-Caps  that are
used on  Old-Style Motors that use the
Small  #17506-000  Brush.

13/16"  Wide with  Inner-Diameter  Threads
"Large-Disk"  Type Brush-Caps that are used on Most Motors that use the
Large  #17788-000  Brush.

7/8"  Wide with  Outer-Diameter  Threads
Steel Rectangle Type Brush-Cover  that
are used on  FC1000/3  "Type C"  Motors that use the  #19463-000  Brush.

Early Version Covers had Cork-Insulation Glued on the Underside.    Later Covers Also had a a Heavy-Paper Shield to help Protect against the Brush-Wire from Shorting against  Motor Housing.
This page was last updated: February 4, 2023
Tachometers  are Built-In to the Back-End of each Servo Motor.    This is the  Velocity Transducer
(DC Generator)  that tells the Servo-Drive how Fast
the Motor is Rotating.    A Properly Working Tach is Critical to Operation of the Servo-Drive.

A Good Clean Tach Assembly,  on Strippit Servo Motors,   will read About  60 to 75 Ohms.    Check it,  Rotate Motor Shaft a Bit by Hand,  and Check it again. Repeat several times more to gain confidence that the Tach is Working OK in  All Positions.

A  Bad Tach will show Thousands or More of Resistance in Ohms.    Usually caused by;

---  Dirty or Tarnished Tach Commutator,  Clean with
     Soft Pencil Eraser or Fine  Scotch-Brite Pad.

---  Stuck Tach Brush.   Take out Holder & Clean out
     with Electrical Cleaner,  and Very Lightly Sand 4
     Brush Sides with 400 or 600 Grit Paper.

---  Bad Tach Armature.   The Potting Compound on
     Armature Shrinks with  Age &  Breaks Wires in
    Armature and  Tach Armature Must be Replaced!

---  Bent Tach Brush Spring,  you can NOT Fix Bent
     Springs,  Springa or Tach Ring Must be Replaced!
     Springs are Bent by  Careless  Brush Insertion!

     I  Carefully  Pull-Back the Side-Of-Spring with a
     Small Screwdriver while Pushing In Tach Brush
     with Another Small Screwdriver,  then Insert a  
     Piece of Paper Clip in Hole to Hold Brush in.
This Tach-Ring is Installed Upside Down!
Tach-Cable is Usually at the
Top of Motor.

This Motor has the Original "Blue"  Type Tach-Ring
Original Type  25-Segment
In the Good-Old Days, 
there was just 1 Type of  Tach-Ring  &  it's Armature,  the  "Blue"  Type.

Then,  there was a 2nd Type,  the  "Black"  Type-Ring  &  it's  "Black"  Type Armature.
The  "Black"  Type Used a Different Size  Tach-Ring,  Armature,  and  Magnet-Set
Inside Motor,  so  None of the Parts are Interchangeable with the  "Blue"  Type!

However,  as Technology Changed and Venders Come & Go,  The  "Color"  of the
Tach-Ring and Tach-Armature has become Almost Meaningless.
I have seen  Blue,  2 Sizes of Black,  Green,  Tan,  Red,  Etc.,  of  Tach-Rings!

There are really still only  2 Types regardless of the Actual Color.
I Measure  Outside Diameter of the Tach Armature to tell them apart.

The  "Blue"  Type of Tachometer Assemblies will have a Tach Armature with a
Outside Diameter  of  about  1.895  Inches.

The  "Black"  Type of Tachometer Assembly will have a Tach Armature with a
Outside Diameter  of  about  1.937  Inches.

To further complicate,  "Blue" Tach Armatures Originally had  25-Segments & Windings.
But to get Better Servo Response at Low Speeds for Laser Continuous Contouring,
a New Type of Armature was Manufactured with  33-Segments  and  Windings.  
As long as they are of the Same Type  (Blue or Black)  and Same Size,  25 & 33 Segment Types are Interchangeable,  but with the 33 Type giving Better Servo Response.
Both  "Blue"  &  "Black"  Tach Rings used Same  #17774-300 Tach-Brushs.

Old Brushes were a Dark-Black Color
as they were made of a
Dry Hard Carbon that sometimes would Wear a Groove into Tach Armature, which would Destroy it.

Later Brushes had More  Graphite  in  the Carbon-Mix,  which provided some Lubrication Properties,  and would Prevent the Wear-Problem as
Machines got Faster & Faster.
These Newer Brushes were Silvery
in Color and had a Waxy Feel.
There are at Least 2 
"Blue"  Types of
Tach Brush Holder Rings,
Part  #17774-100

The  Original  Blue-Color
"Blue" Type

a Late Manufacture
"Blue"  Type that
happens to be
Black  in  Color!

These are Both
"Blue"  Rings in Photo!
Original  "Blue"  Type   25
Segment  Tach Armature  that happens to be Red,  #17774-000

On Left,  Original  "Blue"  Color
Tach really referred Only
to  Tach Ring-Color,
NOT the Armature Color.

On Right,  a Late Manufacture
33-Segment  "Blue"  Type Armature used in Later Motors.
Here is the Real
"Black"  Tach Ring  #17774-500.

And,  it's  #17774-400  "Black" Type Armature.
I Believe that all
"Black"  Tachs used only this Type 33-Segment Armature,
which is  Different  from the "Blue"  33-Segment Armature.

Note!   Most Motors used the "Blue"  Tach.    I Believe The "Black"  Tach  was only used
on some   #17360-000
and   #17538-000  Motors.
Motor Killers
Above are  2 Armatures from Stalled Servo Motors that got So Hot that
Plastic Insulation Melted  and  Oozed Out of the Armatures!

This Starts to Happens at about  400 Degrees Fahrenheit!   The Magnet-Wire Insulation Breaks-Down,  Windings  Short  &  Arc Together,   and  Motor becomes Junk.
Here are Some  (But Certainly Not All)  of the Causes of Servo Motor Failure;

1  ---  The Biggest Cause of Servo Motor Failure is Heat.  
When a Motor is  Stalled,  it Pulls Maximum Current, 
and which can Overheat and Burn-Out a Motor in only a Minute or Two, 
if the Operator is Not Smart Enough to Quickly Shut-Off Machine and Clear the Jam-Up!

---  Some causes are a Jammed  X or Y Axis.   This Occurs when Machine Pulls a Slug
Jamming Part-Sheet,  or  a Punch Sticks-Down causing a  Jam With  a  Short
(Under 3 InchesAxis Move so the Control does NOT Declare a  "Excess Error"  which would Shutdown Servo Drive.    So,  Control keeps telling the Stalled-Jammed Motor
to Move.    If Operator does Not Quickly shut off Machine,  you Risk Burning the Motor.

---  Sometimes the X or Y Axis Limit Switches are Not Working,  or some Knuckle-Head "Adjusted"  Switches to try to get a Little More Travel Length on  Axis.   Then,  if you have a Operator Error,  or  Programming Error,  or  Control Failure that causes Axis to Hit the End of  Axis-Travel,  you Stall the Motor like Above,  and Burn Out Motor.

---  Similar Motor-Killing Jams on Turret from;
    ---  Pulled-Slugs  Jamming Turret to Part-Sheet,
    ---  Too-Tall Tool  Hitting Ram,
    ---  Jammed Part-Sheet  still Stuck to a Tool, 
    ---  Slugs  in Gears, 
    ---  Slug Jammed  between  Lower Turret  &  Anvil  Underneath

When a Jammed Turret tries to make a   <3" Short  1-Station  Move,   there will be
No Excess Error Condition  to  Stop Control from Driving the Servo Motor.
Jammed Turret causes same Stalled Motor Burn Out Problem as Motor Overheats in a Couple of  Minutes while  Operator is Still Scratching His Head on What's Wrong......

Also,  FC1000/1  &  FC1000/2  &  FC1250/30/1500  Machines  with  20-Station Turrets
Rarely  Burned-Out  T-Motors because Strippit used a  Small  8.67  Heater  in the
T-Servo  Overload-Relay  to Protect Motor.    When Jammed,  Heater would
Quickly Heat-Up  &  Trip-Out  similar to a Circuit-Breaker and Saving the Motor.

But,  when Strippit changed to  33-Station Turrets,  they  Changed the Heater Size to a
Large  21.4  Heater  that would Never trip-out before Motor Melted!   I sometimes
change  21.4  Heater Down to about a  10.0  to  13.00  Size  to help prevent this problem.

FC1000/3  Machines  with  G.E. Model 3 Servo  used a  Electronic Overload  instead of
the  Heater & Overload-Relay  as it was  Cheaper for  G.E.  when building Servo Drives.
Electronic Overloads  NEVER Trip  to Save the Motor on these Machines.
I sometime Retrofit the old Heater & Overload-Relay on to these Machines,  in the Field.
Last Project I Did before Leaving Strippit was Designing this  Overload-Relay Retrofit
which  Strippit  Added to Production FC1000/3 Machines Starting at  Serial Number 200.
These Same Technicians Then think a Megohmmeter  is The-Answer,
and will tell them a  "Bad"  Motor.
In Most cases,  this is Also Wrong!

Ohmmeter  puts out about a Volt or 2,  and then Measures Current Flow,
to Determine the Resistance of a Circuit.

Megohmmeter  uses a Hi-Voltage to do the Same thing.    My Megohmmeter at
Left can Put-Out Over a Thousand Volts!
The Idea is,  at Hi-Voltage,  Weak,  Bad,
or  "Cooked"  Insulation will Break-Down
and the Megohmmeter will Detect it.

But, You usually can Not Read Insulation
Breakdown,  Winding to Winding,  with
Either Type of Meter!     Both Melted  &
Shorted Armatures in Picture Above will
Pass Megohmmeter Test at the Highest
1000 Volt Setting,  yet are Quite Bad!

The Magnet Shell
at Right Got So Hot
that Glue that Holds Magnets inside
Broke Down,  and all
Magnet-Segments came out when Motor
was Disassembled.

It's Junk Now Also.

Some Technicians try to Determine a Shorted or Burned-Out Motor with a Ohmmeter. You  Can't!!!

Most Motors Burn-Out by Shorting their Windings Together,
and   You Can Not Ohm This Problem Out!!!
These Technicians Meg the Armature to Ground.
As there is Always Dirt and Carbon Dust Coating Inside of Motor,
they Will Always get a  "Reading".
They then Declare Motor is  "Shorted",  and send it out to be Rebuilt.
The Motor could Indeed be Bad,
But This Test will  NOT  Prove it One Way or the Other,
as this is  NOT  the Normal Failure Mode!
3  ---  Another Common Cause of Motor Failures is Worn-Out Brushes.

Customers Fail to do Routine Maintenance like Checking their  3  (X, Y, T)  Servo Motor Brushes,  which then Wear-Down Until they Destroy the Motor Commutator, 
and possibly also the Servo Drive Electronics.

I can Sell You New Brushes  or  I can Sell You  Motors  &  Servo-Drives.   Your  Choice.

Below Photo Shows a New Brush on the Left,  and  3 Worn-Out  &  Broken Brushes
I  Dug-Out  of a  Customer's Motor.     They got to Buy a New Motor.
4  ---  Another Common Cause of Motor Failures is Impact Damage.

Motors are Relatively Fragile.    Impacts can Break the Magnets Loose inside Motor, 
Pull Out the Studs Holding Motor Together,  and Break the Resolver Feedback Package Off the End of Motor,  among other Failures.    People in Shops Run Into Motors with their Fork-Lifts and Bump them with Work-Tables.     Put Guard-Rails around Machine!

Replacement Motors and Motors being Returned for Credit are Often Damaged by Shipping!    They Must be Very Well Packed in a Heavy-Duty Carton with Lots of Tight Packing Materials.    I Now  Double-Pack  the  Bigger Motors inside  2  Boxes!

I often get a Return Motor Back that was just Thrown into a Box with Little or No Packing Material around it,  and it comes-in with Part of Motor Sticking Outside of Box!
Needless to say,   These Damaged Motors Do NOT Receive Credit for the Return.
2  ---  More Motor Heat Failures are caused by No Cooling Air-Flow.
        The X & Y Motors,  and the T  Motor on some Machines,  are Forced Air Cooled.
        --  Is there a Strong Air-Flow coming out of Motor?
        --  Is the Cooling Fan Motor Running?
        --  Is the Air Filter Clogged-Up?
        --  Are the Air Hoses Rotted out?
        Find and Repair the Above Problems!!!
5  --- Local Motor Shops  Permanently Kill  a Lot of Servo Motors.

When a Shop Burns-Out a Servo Motor on one of their Machines,
they usually try to go Cheap,  and   "Give the Local Motor Rewind Shop"   a Try.   
The Problem Is,  Most Motor Shops are Set-Up to  Rewind  A.C. Motors,
NOT   D.C. Servo Motors,   which are  Very Different!!!

These Motor Shops  Always  Do  1 of  2  Things;

A ---  They Take Apart Motor and Damage Armature & Tach-Armature & Magnet Shell Further.   They then  "Cut"  Commutator,  usually Improperly,  which Ruins this Critical Part.    Finally,  they replace Bearings,  Cut-Down and Adapt some Brushes to Fit,  Paint It,  and Declare it  "Rebuilt".     When Customer gets it Back,  it is Still Bad or even Worse than Before.    Then Customer  (You)  is Pissed as you now have a "Rebuild"  Bill  and your Machine is Still Not Running,  and You & Repairman Still Don't Know What's Wrong.

B ---  Or,  They usually Damage Magnet-Shell,  Armature,  and Fragile Tachometer Armature because they do Not Know how to take Motor Apart.   They then Screw-Around with Motor a While,  then they Give-Up,  Throw All Parts Loose & Damaged in a Box,  and return the Whole Mess to Customer.   Then Customer sends it to Me for a  "Trade-In",  as I Sell Most Motors on an Exchange Basis.   I have been Repairing Strippit's for Over 34 Years and I have seen  "A"  &  "B"  above,  Over  &  Over  Again!
If Anyone has Opened-Up Motor & Tried to  "Repair It"  I No Longer  Give Any Credit!

Below,  is a Photo of 1 such Servo Motor  Just as I Received It from a Customer,
             who used a   "Local"   Motor Shop to   "Try to Rebuild".

---  Motor Arrived with  Shaft Sticking Out of Box.
---  All Parts were  Loose Inside Box.
---  Tach Ring is  Broken in to Pieces.
---  Wire was  Stripped-Off  Motor Armature  &  Commutator,  Damaging Both.
---  Tach Armature had it's  Wire Stripped-Off,  and is  Broken into 2 pieces,
---  Many Parts are Missing.

So,  For those of You who are a Little Slow on the Up-Take Here,

Do NOT Take Your Servo Motor Apart,
You  Will Damage It !!!
Do NOT Take Your Servo Motor To The  "Local"  Motor Shop,
They  Will Damage It Even More!!!
Because of this Problem,  I started Rebuilding Servo Motors for Strippit Machines 30+ Years ago.   All My Servo Motors are  Washed,  Armatures are Completely Rewound,  Magnet Shells Replaced if Necessary,  Brush Holder Problems Repaired,  Tach Ring
and Tach Armatures Repaired,  New Brushes Installed,  New Bearings Installed,  and any other Problems Repaired.

And Finally,
Every One of My Servo Motors are Run on One of My Strippit CNC Punch Machines,
and  Tested for  Proper Operation,  Tuning,  and  Accel  &  Decel Characteristics.

No one Else in the World Does This,   Servo Motor Testing on a Real Strippit Machine,
so  We & You Know that it is a Good Motor that will Perform to Spec on Your Machine.

Motor is then Painted & Boxed-Up after this Final Machine Testing,
so  we can Just Pull-It off the Shelf for Quick Overnight Shipping.
6  ---  Resolver Feedback Packages  and  Couplings  Eventually Wear-Out and Fail.  

Cables going to the Feedback Package can also Fail.

This Loss of Position Feedback can Then cause Axis to Run-Away and Crash into the End of Axis Travel,  which can cause both Mechanical Damage and Heat Damage to Motor from being in a  "Stalled"  Condition.

If you see occasional Axis  "Jumping Position"  this can be a Warning Sign that Resolver Feedback Package   or  Cables are Wearing out.
Fix  or  Replace Now  to Prevent More Problems!

Resolver Feedback Package


Resolver Coupling

We Keep Both of these
Parts In-Stock.

To Recap,  We Stock Strippit;

---   D.C. Servo Motors
---   Do Servo Motor Testing & Rebuilding
---   Motor Brushes
---   Brush Caps
---   Tachometer Armatures
---   Tachometer Rings
---   Tachometer Brushes
---   Resolver Feedback Packages
---   Feedback Cables
---   Resolver Coupling
---   Servo Motor Electronic Drives
---   Servo Drive Electronic Repair Parts
---   Servo Drive Electronic Testing
Above is a Servo Motor,   as I received it,
after a  "Local Shop"  tried to Rebuilt it.    It's All Junk now.