Strippit 20-Station Turret

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 the Shortest-Path to the Next Tool Station that was Programmed.

This was a Large Improvement over the Crude Clutch & Brake 1-Direction 20-Station Turrets that Strippit used on the  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

Control

FC1000/2 Machine

The First 2 years production of FC1000's used a Turret-Drive System with a Odd Gearbox with the Servo Motor Underneath it, and hanging Upside-Down so the Resolver Feedback Package almost touched the shop floor.  This system actually worked quite well, but had 2 Problems.  It was almost Impossible to adjust the Resolver, and Oil Leaking out of the Gearbox ran directly into the Servo Motor & Resolver causing many Problems.  Many of these old NC FC1000's have been scrapped, and Most of this discussion of Fixes does not apply to this type of Drive.

About 1976, Strippit Redesigned the Turret Drive into the 2nd and Most Common Type.  This 2nd Type of Turret-Drive was thereafter used in all  FC1000's,  F1000/2's, and FC1250/30/1500 Machines until the 33-Station Machines came out in the early 1980's.

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

The 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 the Hardest Type of Work-Load on Drive Components. 

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

The Turret Drive actually worked

Quite Well when new, but over time,

the 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 the 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 that 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 the 2 Drive Chains.

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

       This is hard to do with out a 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 the Drive Shaft can be Removed,  Pull it out,

       and set it on a work table.

5 --   Replace All the Keys in the 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 start          wearing out again Immediately.   I have a Machine Shop Surface Grind me  .002"

        oversize Keystocks  ( .252" and .377" sizes),  Bevel the Ends, and then I Press-In

        Tight Keys with a Arbor-Press,  or Carefully Pound them in with Brass Rod & a Brass

        Hammer.   If they are not Very Tight, do it over again until they are!

6 --   Many times Top & Bottom Turrets will  "Slip"  out Position with each other too easily.         This is because the Coupling between the Upper and the Lower Drive Shafts is not

       Centered Properly,  and it Holds 1 Shaft better that the other.  Take apart the

       Coupling,  clean it, and install it on the Lower Shaft.  Make sure the End of the Shaft is

       in the Middle of the Coupling.

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

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

9 --   Using the 2 Jack-screws,  Jack the Backplate so the Chains are pulled tight, 

        but Not Too tight.   Tighten Backplate.

10 --  Using a Bar, turn the Lower Turret, then the Upper Turret, and Position the 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 the Shotpins until they Do Not Move.

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

12 --  The last thing to do , is to  "Rezero"  the 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 the Resolver in the

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

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

13 --  Now, have someone Index the Turret Station-To-Station Back & Forth (Station 1 to 2

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

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

        will Still be some  "Slop"  in the System, as there is some Slop in the Gearbox, and   

        the Out-Put Coupling is Very Loose by Design.  So we are trying to Balance the

        remaining Slop by Positioning the Resolver-Setting in the Middle of it, as the 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"  the Drive Shafts, and do not depend on Just the Little 1/4" Keys to Handle the 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 the 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 2, 2007

---  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 these Every Time you Remove a Stud, as a Stripped-Nut is Very Hard to Remove from Under Top Turret.  Our's does Not Strip the Threads as easily as Original Nuts that 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

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

     Welding a Short  6-Point  7/16"  Socket on a  1" x 10"  Piece of  1/8" Steel.  

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

And Now Is The Time To Fix All The Tool Stations In The 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.