Strippit  20-Station Turret-Drive

Problems  &  Fixes

In 1975,  Strippit Introduced their FC1000 Series of Machines.  These Machines had a

20-Station Bi-Directional Servo Controlled Turret,  so the NC & CNC Control could

always Plot & Move Shortest-Path to the Next Tool Station that was Programmed.

This was a Large Improvement over Crude Clutch & Brake 1-Direction 20-Station Turrets that Strippit used on  FC30/30  &  FC30/40  Machines built in the early 1970's.

This discussion does not pertain to these early  FC30/30 &  FC30/40 Machines.

If you Still have a  FC30/30  or  FC30/40 Machine,  You Should Scrap-it Today!

Strippit

HECC80/1

CNC Control

FC1000/2 Machine

First 2 years production of FC1000's used Turret-Drive System with a Odd Gearbox with

Servo Motor Underneath Gearbox Hanging Upside-Down so Resolver Feedback Package

almost touched shop floor.  This system actually worked quite well,  but had 2 Problems.

It was almost Impossible to adjust Resolver and Oil Leaking out of Gearbox ran directly

into Servo Motor & Resolver causing many Problems.

Most of these old  A-Control  NC  FC1000's have been Scrapped and Most of this

discussion of Fixes does not apply to this type of Turret Drive.

About 1976,  Strippit Redesigned Turret Drive into the 2nd and Most Common Type.

This 2nd Type of Turret-Drive was thereafter used in all  FC1000/1,  F1000/2,  and FC1250/30/1500  Machines until the 33-Station Machines came out in early 1980's.

Over 500 Machines were built with this type of Turret-Drive.   Many are Still in active production use,  and we will show some of their Problems and Fixes.

Bi-Directional Turret-Drive is Great for Production Productivity  (Saves Time) but is Hard on the Drive Components.  Mechanical Engineers call it a

"Reversing Load"  and it is hardest type of Work-Load on Drive Components. 

This 2nd Type had a New Gearbox Type, with Servo Motor now mounted above Gearbox,  and  Resolver Feedback Package pointed Upward were it was fairly easy to get at.

ThisTurret Drive actually worked

Quite Well when new,  but over time,

System Loosened-Up and became Mechanically Sloppy from the Thousands & Thousands of Back & Forth Turret Moves,  as well as  "Crashes" from  Operators putting in  "Too Tall" Tools that would  Crash into the Ram when Turret was Rotated.

So Turret  Rotation-Positioning would Gradually Deteriorate,  Shotpins would "Clunk-In"  Harder & Harder,  until Finally, they would Not Go-In at All,  and Machine would Stop with a  "Pins Timeout"  and a

"All Hold Condition".

At this Point,  You Need to

Rebuild the Turret Drive System!

There are 2 ways to Rebuild the Drive System.

You can Rebuild it as it was Originally, or you can try to Improve it.

To Rebuild it as Original;

1 --   Loosen the Drive Backplate & Jack-Screws,  and remove 2 Drive Chains.

2 --   Pull the Upper and Lower Turret  Sub-Assemblies. 

       This is hard to do with out a Dowel Pin Puller.    See  Dowel Pins & Dowel Pin Puller!

3 --   Un-Spiral  the  Upper  &  Lower  Rings on the  Big White Output Gearbox Coupling,

       so that it is  "Free"  from the Drive Shafts.

4 --   Unbolt the 3 Pillow-Blocks so that Drive Shaft can be Removed, 

       Pull it out,  and set it on a work table.

5 --   Replace All the Keys  in  2  Sub-Assemblies,  Chain-Sprockets,  and  Top & Bottom

       of Coupling.    All Keys Must be Very Tight!!!    If Keys are Not Tight,  they will start

       "Rocking"  as soon as Turret is used again   (Reversing Load,  Remember?),  and

        will start wearing out again Immediately.    I have a local Machine Shop

        Surface-Grind  me  Special  .002" Oversize Keystocks  ( .252"  and  .377"  sizes), 

        Bevel the Ends and the 4 sharp side-corners,  then  Press-In Tight Keys with a

        Arbor-Press,  or  Very Carefully Pound them in with  Brass Rod  &   Brass

        Hammer.   If they are Not Very Tight,  Do it over again until they are!

6 --   Many times Top & Bottom Turrets will  "Slip"  out of Position with each other too

       easily.   This is usually because Friction Coupling between Upper and Lower Drive

       Shafts is Not Centered Properly,  and it Holds 1 Shaft better than the other.

       Take apart Coupling,  clean it,  and install it on the Lower Shaft. 

       Make sure  End of Each Shaft is in the Middle of the Coupling  and  almost touching.

7 --   Install Top Shaft and Top of Coupling,  but do Not Tighten fully.

8 --   Reinstall  Sub-Assemblies,  Drive-Shaft,  Coupling,  and  Chains on Machine.

9 --   Using the 2 Jack-Screws,  Jack the Backplate Backwards so the Chains are pulled

        tight,  but Not Too tight.    Tighten Backplate Bolts to Machine Frame..

10 --  Using a Steel Bar in a Shotpin Bushing,  Carefully turn Lower Turret,  then Upper

        Turret,  and Position Same Tool Station Under the Ram.   Manually Fire-In the

        Shotpins,  Turrets should both Pull-In to Position as the 2 Shotpins go in.   Manually

        Fire Shotpins In & Out several times, Turrets should NOT  "Scissor"  or  Move as

        you do this.   If they do,  Manually,  with a Bar,  move them slightly,  and repeat

        with Shotpins until they  Do Not Move.

11 --  Now Tighten Top of Shaft Coupling.   I use Hardened Washers under the Screws.

12 --  The last thing to do,  is to  "Rezero"  Turret.   I have a Precise Way of doing this

         with an Oscilloscope,  but you don't have that option.  Turn-On Machine,  and Try

         to  "Home"  the Turret.   If Shotpins go in,  Great.   If not,  Turn Resolver in the

         Feedback Package on End of the Servo Motor a  1/4 turn,  Hit the  "Clear-All" 

         Button on Control,  and try again until they finally Clunk-In. 

13 --  Have someone Index the Turret Station-To-Station Back & Forth  (Station 1 to 2 and

        back to 1 repeatedly)  while you Slowly Turn Resolver Back & Forth until you get 

        Best Turret Positioning,  in  Both Directions,  as the  Shotpins Fire-In.  

        Try to Not get Your Fingers  &  Arm Caught in the Chains!!!!   There will Still be some

        "Slop"  in the System,  as there is Slop in Gearbox,  and output Coupling is Very

        Loose by Design.   We are trying to Balance the remaining Slop by Positioning

        Resolver-Setting in the Middle of it,  as Turret goes Back & Forth.   Lock-Down the

        2 Resolver Screws,  do Not Over-Tighten Screws as they Strip-Out Very Easily!

The

Upper Turret

Sub-Assembly

The

Lower Turret

Sub-Assembly

At Machine Technologies,

We Always Try to Improve the Original Design where Possible.

1  --  We rebuild the Turret Drive, much like the above Instructions.  But we use some Newer & Better Parts to try to Improve the Drives Performance & Longevity.  

First,  we use 2 Taper-Locking Chain Sprockets that  "Grip"  Drive Shafts,

and do not depend on Just the Little 1/4" Keys to Handle Rotational Torque.  Keys are the Weak-Link in this Drive System.

2  --  Then we use a Custom-Made Gearbox Output Coupling to Replace the Sloppy Original Coupling. 

This does 2 Good Things for us;

---  It Eliminates All the Internal Slop that the Original Coupling Has Built-In.

---  It Tightens & Locks onto the 2 Shafts in Addition to still using the Keys, so it handles the Torque Much Better without wearing & loosening.

Because there is so little space to work with,  we also make a Off-Set Block to Move the Lower Pillow-Block Upward so that we have enough space to fit the New Coupling.

3  --  When Done,  the

Rebuilt Turret Drive System,  with New Parts,  will looks like this.

The New Parts are Not Cheap,  but it does make System Work Much Better when Properly Installed.

Either Way,  Rebuilding the Turret Drive System will Probably take you 2 Days,

and is a Dirty Job.

Take your Time,

and Do It Right!

Because it is Necessary to Rebuild it Right if you want your Machine to Work Well,  and make the Parts you need.

This page was last updated: February 3, 2023

---  Standard Strippit Lifter Spring,

     Part  #17591-000

---  Our Heavy-Duty Lifter Spring for 3 1/2" Stations Only,  Improves Stripping Action,  Part  #17591-HD

---  3 1/2" Tool Lifter, 

     Part  #100245-000

---  Stud Nut,  Part  #17590-000.  Replace Every Time you Remove a Stud,  as a Stripped-Nut is almost Impossible to Remove from Under Top Turret.  Our's does Not Strip Threads as easily as Original Nuts Strippit used!

---  2x2 Notch Unit  Tool Lifter in Station #1 in Most Older Strippit Machines,  Part  #200285-000

---  Lifter Stud,  Part  #100726-000

---  Strip-Target,  for all 3 Lifter                 Types,  Part  #17351-000

---  1 1/4" Tool Lifter, 

     Part  #100811-000

---  Make Yourself a   Stud-Nut Removal Tool   (Like in Picture Above)  by Welding 

a  Short (Grind It Down)  6-Point  7/16"  Socket  on  1" x 10"  Piece of  1/8" Steel.

You can also use it as a  Feeler Gage  to Maintain the 1/8" Gap under  Strip-Sensor.

And Now  Is The Time To Fix  All  The Tool Stations  In  Upper Turret!!!

We Keep All The Repair Parts Shown Below,  and Many Other Parts,  In-Stock!

Note!   Over Time,  Many Gearboxes slowly Lose All the Gear Oil Inside,

Drip by Drip, Until the Gearbox is Empty.   Then, Your Gearbox Slowly Grinds the Gears and Bearing to Metal Dust.   Check Oil Level Yearly!

Gearboxes are Hard to Fill.   I have Found that the Best Way to Fill,

is to Remove the 4 Bolts & the Middle Cover Plate,

then to Very Slowly Fill Gearbox to the Top with  90 Weight Gear Oil.