Mechanical

REMOVING THE APRON FROM XL-LTD
This procedure will use pages 75 and 79 of your owner’s manual as references.  Please have the manual at hand when working on the machine and when   calling Smithy Co. for assistance.   The apron is removed with the lead screw still installed in the apron.  This prevents the worm gear inside the apron from   falling out off place. 
PROCEDURE
  1. Remove the taper pin 18 pg.75 from the left end of the lead screw.  This is a tapered pin and must be driven out from the small end.
  2. Remove the 2 screws 22 pg. 75 from the right support of the lead screw and remove the support 19 pg. 75.
  3. Slide the tail stock off of the machine.
  4. Remove the 2 screws 30 pg. 75 from the front support of the crossfeed screw and slide the table back away from the front support 40 pg. 75 far enough to be  able to get to the 4 screws holding the apron on.
  5. Remove the 4 screws 33 pg. 79 that hold the apron to the carriage.  The apron will drop down far enough to allow the apron gears to disengage from the  toothed rack on the front of the machine and let the entire carriage to move freely left and right.
  6. The apron will not drop down far enough to come free from the carriage because of the two taper pins 37 pg. 79 that go through the carriage into the apron. 
  7. Loosen the two carriage gib adjustment screws 9 pg. 75 to allow for easier removal of the carriage. With the assistance of a helper, slide the carriage, table an  apron assembly off the end of the machine just enough to be able to remove the apron then put the carriage back onto the machine.
  8. Tap the two taper pins 37 pg. 79 up and out of the carriage. DO NOT REINSTALL THESE PINS, LEAVE THEM OUT. This will allow the apron to be reinstalled  without removing the carriage from the machine.
  9. To remove the leadscrew, turn the apron upside down and remove the cover10 pg.79.  Pull the leadscrew from the apron and watch the position of the worm  gear 23 pg.79 so you will know how to reinstall it properly.  There is also a key 22 pg. 79 inside of the worm gear.  Make sure the key is in place when reinstalling the gear and screw shaft.
  10. Reverse the above procedures for  assembly.
CHANGING THE HALF NUT ON XL-LTD
This procedure will use page 79 of your owners manual and the instruction sheet “REMOVING THE APRON FROM XL-LTD” AS REFRENCES.  Please have the   owner’s manual at hand while working on the machine and/or calling Smithy Co. for assistance.
PROCEDURE
  1. Remove the apron and leadscrew as per instruction sheet “REMOVING THE APRON FROM 1220XL- LTD”.
  2. Remove the setscrew, spring and ball 75,76, 79 and setscrew 77 from the apron.
  3. With  the apron upside down,  turn and push  the half nut shaft  62  into  the apron until setscrew 78 is visible.  This is the setscrew that holds the half nut in  the holder.
  4. Loosen setscrew 78 enough that the half nut can be removed from the shaft 62.
  5. Place new half nut on the end of shaft 62 and tighten setscrew 78enough to secure the half nut into place but not so tight that it can not rotate freely on the end  of the shaft 62.
  6. Reinstall setscrew 77 while rotating shaft 62 to allow the setscrew to seat into the machined grove on the side of the shaft.  The setscrew is in the grove when  the half nut shaft moves in and out when the shaft is rotated.  Do not tighten the setscrew so tight that it causes the shaft to drag or bind when rotated.
  7. Reinstall the ball, spring and setscrew 75,76,and 79.   Tighten the setscrew until the detents can be felt when the shaft is rotated.
  8. Refer to “REMOVING THE APRON FROM 1220XL-LTD” for installation of the leadscrew
Removing the Powerfeed Engagement Box Midas 1220XL-LTD
Removal of the directional control box requires the lead screw be removed from one end of the box and the change gears be removed from the other end.  The   items referenced in these instructions can be found in the parts diagrams of the owner’s manual.
    1. Remove the screws that hold the right hand trestle (19) in place and separate the trestle from the end of the lathe bed casting. (page 75) 
To do this:
      • Move  the carriage as far to the left as it will go
      • Pull the trestle away from the lathe bed casting until the alignment pins are clear
      • Remove the taper pin (18) from the coupler (24) on the left-hand end of the leadscrew. (page 75)
      • Slide the leadscrew out of the way by engaging the half-nut, and moving the table to the right.
      • Remove the “D” gear (page 42) from the machine and drive out the pin holding the spline housing (6) on the shaft.  Remove the sleeve and washer.  (page  84)
      • Remove the change gear quadrant (2).  After removing the adjusting bolt, the spacer (1) should slide out easily.  If the spacer does not slide out easily, then it may be too thick.  This pushes the gear change quadrant out of alignment, and interferes with the smooth meshing of the gears involved.  Face the spacer  down slightly until it fits correctly (not too lose, not too tight). (page 84)
      • Remove the three screws and the pedestal (16) from around the end of the “D” gear shaft. (page 77)
      • Remove the 4 socket head cap screws (12) that hold the selector box to the front of the machine and pull the box free (page 77).  You may need to loosen the sheet metal pulley box to do this. 
To loosen the pulley box:
    • Loosen the two 14mm hex head bolts at the bottom of the pulley box (page 42)
    • Loosen the 6mm cap head socket screw in the middle (acts as a stop for the middle pulley tensioner assembly)
    • Remove the middle pulley (page 86) by turning shaft #9 counter clockwise until the whole assembly comes off. 
    • Loosen the revolution axis (9, page 87), and sometimes there will be a flat head screw just above the spindle pulley. 
    • Pry the pulley box out and the direction box should come out.
REMOVING THE QUILL & QUILL FEED ASSEMBLIES GN-1220 LTD
Have the owner’s manual available when doing any machine maintenance. The  items referenced  in these instructions can be found in the parts section of the  owner’s manual on page 70 unless otherwise specified   MAKE   SURE   THE   MACHINE   IS   UNPLUGGED   BEFORE   STARTING   ANY MAINTENANCE  PROCEDURES      Note: There is a hidden screw located under the feed dial, it will be necessary to remove the dial to get to the screw.
  1. Release the tension on the quill retract spring by loosening the setscrew (109) that comes in underneath the spring housing.   Be sure the quill is retracted  into the millhead completely, and to hold on to the spring housing with a rag or a glove so it does not spin suddenly.  Then remove setscrew 110 on the dial side, opposite setscrew 109.
  2. Unscrew and remove the spring cap (65).
  3. The outer part of the spring is still under tension, and can be dangerous if pulled out of the housing!  Now you will need to unhook the inner part of the spring  from the screw (108) on the shaft (107).  Use needle nose pliers and a flathead screwdriver while rotating the shaft to unhook the spring.
  4. Remove the screw (108) with needle nose pliers from the side, and slide the spring housing out of the casting while making sure the spring stays inside the  housing.*
  5. Pull knob (91) outward to disengage the fine feed and remove the knob.
  6. Remove setscrew (96) from  the handle seat  (89), and then  turn  the feed handles until  setscrew (86), spring (87), and ball (88) are facing down. Lock the  quill in place and remove the setscrew(86).
  7. Tap the dial with a non-metallic mallet to dislodge the spring and ball.
  8. Use two screwdrivers between the dial face (98) and the feed housing (101) to pry the dial off the shaft.
  9. Remove the 3 screws (99&100) and pull the feed assembly put of the casting.
  10. Remove the setscrew (69) from the casting, support the quill with one hand and release the quill lock. Lower the quill out of the casting.
ASSEMBLY
  1. Basic assembly is the reversal of the above steps.
  2. It is important to make sure all parts are clean and properly lubricated where needed.
  3. A thin coating of light grease should be applied to any sliding or rotating surfaces before assembly.
*NOTE:   If you should need to remove the spring, the easiest way to rewind the old spring is to make a mandrill from a piece of round stock about ½ inch in  diameter. Drill and tap a hole in the rod for a screw similar to the end of the shaft (107) on the machine where the spring is to be installed. Put the mandrill in the lathe chuck and slip the spring over the screw head. Drill and tap a hole in the side of a lathe tool and install a screw similar in size to the screw in the spring  housing. Put the tool in the tool post in a manner that the screw head can be hooked to the  end of the spring. Slowly turn the lathe spindle by hand as you also  feed the tool post inward to keep pace with the spring as it winds up and gets smaller and smaller in diameter. When the spring is wound to a size smaller than  the spring housing, wrap wire around the housing to hold it wound while you remove it from the mandrill and install it into the housing.
CROSSFEED BACKLASH ADJUSTMENT 1220 XL OR LTD
Excessive backlash in the crossfeed can be coming from 2 different places.
  1. The fit of the crossfeed screw to the front screw mount.
  2. The fit of the crossfeed screw into the brass crossfeed nut.
  3. The tightness of the screw support bushing on the front of the crossfeed table.
There are adjustments for each of the above areas. Before making any adjustments to the crossfeed screw system, it is recommended that all the gibbs on the  table and carriage system be checked and adjusted as per the owners’ manual.
CROSSFEED SCREW TO FRONT MOUNT
Slowly turn the crossfeed handle clockwise and watch the gap between the dial and the front screw support mount. Change directions and note if the gap  increases slightly. If so this is a sign that there is some play in the mounting. To reduce this play, accomplish the following.
  1. Check the setscrews (one or two) holding the support bushing in place for tightness.
  2. Place shims between the dial and the support casting. To do this, remove the nut holding the handle in place and pull the handle and the dial off the end  the screw shaft. Remove the key from the shaft and install the shims on the shaft next to the support casting.
  3. Install the key, dial handle and nut.
  4. Recheck the backlash.
CROSSFEED SCREW TO BRASS NUT
If there  is still an excess of backlash after the above adjustments are made, the play will be between the crossfeed screw and the brass nut. The following  rocedure covers adjustments of the nut.
  1. Remove the crossfeed screw rear support.
  2. Crank the crossfeed table toward the operator side of the machine. Watch under the table from the backside and stop before the crossfeed screw comes out  of the brass nut.
 Y-Feed Backlash Adjustment
Fig 1 – Standard setup
    
Fig 2 closer
   
Fig 3 Chosing a metric pitch. M0.75 or M1.5 A = 53 B = 32 C = 42 D = 48
 
Fig 4 – Remove all the gears.
Loosen the socket head cap screw and allow the mounting
plate to move.
   
Fig 5 – The plate will move
in the radius slot and will
bring the A and B gears
together.
 
Fig 6 – B/C gears mounting
shaft has a t-slot back. When the shaft is loosened,
it will slide left and righ and
allow the B/C gear to mesh
with the D gear.
   
Fig 7 – The spline goes on the
shaft/ Finger is pointing to the
B/C shaft
 
Fig 8 – The E gear shaft is
above the B/C gear shaft. It allows LH threading and
bridges some gear
combinations.
   
Fig 9 – The E gear shaft moves
like the B/C gear shaft. The
upper corner of the mounting
plate may require some
grinding to fit past the a
gear shaft.
 
Fig 10 – E gear shaft run all
the way up and locked in place.
Spline is installed.
   
Fig 11 – Install the D gear
first and put the C-clip
in place.
 
Fig 12 – Install the C gear on
the B/C gear shaft
   
Fig 13 – Slide the C gear so
it meshes with the D gear.
 
Fig 14 – Install the B gear on
top of the C gear. The B
gear can be larger than
the C gear and can hide
it when installed.
   
Fig 15 – B and C gears
installed, shaft locked in
place and C-clip installed.
It is often easier to install
the C-clip. then mesh the
gears, lock the shaft.
 
Fig 16 – Tighten the B/C shaft to lock the gears in place.
   
Fig 17 – If the E gear shaft
interferes with the gears,
slide it to the end of its travel and lock in place.
 
Fig 18 – Install the A gear and
install the C-clip to keep it in place.
   
Fig 19 – Install the A gear
and then the C-clip. Rotate
the mounting plage until
the A and B gears mesh.
 
Fig 20 – Tighten the socket
head cap screw to lock the gears in place
   
Fig 21 – E-gear install. At
times you may need to install the E-gear to bridge
between the D gear and
the C gear.
 
Fig 22 – Since this gear is
simply acting as a bridge,
the number of teeth is not
critical. Use a gear that fits
well in the space.
   
Fig 23 – Once the E gear
is locked in place, lock the
B/C gear shaft and rotate
the mounting plate to mesh
A and B. Tighten the socket head cap screw..
 
Fig 24 – The gears are
installed.
  

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