Rebuilding the head on a South Bend 4219 1956 mill

20170919_142628.jpg 20170919_142611.jpg OK, the long title says it all, I have an older southbound mill that I really enjoy, it's heavy, only has 1 hp, but she is pretty solid and a ram head. No nod, but she does tilt side to side.
I am in the process of collecting information on what I am going to need to do to rebuild the head and replace the spindle bearings on this machine. The information on this machine is a little sparse, though, not much is needed because the machine is fairly straight forward in design and construction.
Any info you might be aware of I'd would apperciated, very interested in info on taking apart the head and any adjustments alignments I should be aware of before I start pulling her apart.

Some pictures of the machine , head and the name plate.
20170919_142809.jpg 20170919_142809.jpg
View attachment 242089

20170919_142709.jpg

20170919_142640.jpg
 
That spring is ~definitely~ not OEM. The knurled knob in the middle of the boss is to engage the clutch (it allows the female portion of the quill drive gear to extend and meet the quill boss and handle). With the Hydraulic Feed or the Fine Feed wheel this is important, because the basic design allows the handle to be disconnected (and not be driven by the Hydraulic feed or the Fine feed wheel). With the spring you have, that function is bypassed. For mills with just the fine feed, it's perfectly acceptable, but with that Hydraulic feed, it is an accident waiting to happen. That hydraulic feed was and is cantankerous. I went through and rebuilt the hydraulic feed controls and cylinder...the "fun" almost never ended... :p
 
Speaking of the fun... Rebuilding the Hydraulic Power Feed unit isn't all that hard:

Parts Manual Section, Description, South Bend Part Number, O-Ring Dimensions, "Generic" SAE AS568 Part Number

O-Ring Part Equivalents:
Qty (1) 1901A Section 7; Feed Control and Selector Blocks, Part #40, SB Part #193x3, Fine Downfeed Adjuster O-Ring 5/16" x 3/16" x 1/16", Generic Part #AS568-008

Qty (6) 1901A Section 7; Feed Control and Selector Blocks, Part #14, SB Part #193x5, Hydraulic Power Feed Gallery Face O-Ring Seal 3/8" x 1/4" x 1/16", Generic Part #AS568-010

Qty (2) 1901A Section 7; Feed Control and Selector Blocks, Part #30, SB Part #193x7, Rapid Switch O-Ring 1/2" x 3/8" x 1/16". Generic Part #AS568-012

Qty (1) 1901A Section 7; Cylinder Block and Rack, Part #7, SB Part #193x10, Piston Rod O-Ring 11/16" x 1/2" x 3/32", Generic Part #AS568-112

Qty (1) 1901A Section 7; Feed Control and Selector Blocks, Part #12, SB Part #193x22, Selector Boss O-Ring (version 1) 1-1/8" x 1" x 1/16", Generic Part #AS568-022

Qty (1) 1901A Section 7; Feed Control and Selector Blocks, Part #13, SB Part #193x24, Selector Boss O-Ring (version 2) 1-1/4" x 1-1/8" x 1/16", Generic Part #AS568-024

Qty (1) 1901A Section 7; Cylinder Block and Rack, Part #4, SB Part #193x133, Piston Seal O-Ring 2" x 1-13/16" x 3/32", Generic Part #AS568-133

Qty (2) 1901A Section 7; Cylinder Block and Rack, Part #3, SB Part #193x134, Piston Cap O-Ring 2-1/16" x 1-7/8" x 3/32", Generic Part #AS568-134

Most of it is self-explanatory. However, for those of us (all of us) who need to replace the Hydraulic Piston Seal O-ring, here's a ti:. The Transfer Ports into the Hydraulic cylinder liner are razor sharp and will neatly take a bite out of your new Piston Seal O-ring. To avoid this, use a piece of shim stock to cover the port while inserting the piston:

First put the shim stock (about 0.001"-0.002" thick) into the cylinder, covering the transfer port.
Insert the piston, while applying a bit of finger pressure to hold the shimstock in place.

294225

Slide the piston past the transfer port, and remove the shim stock...
294222

No fuss, no muss, a lot less cussing...
 

Attachments

  • 20190415_165548.jpg
    20190415_165548.jpg
    37.9 KB · Views: 0
  • 20190415_165626.jpg
    20190415_165626.jpg
    52.1 KB · Views: 0
Gib lock day: The X-Axis Gib Locks were able to be de-rusted and de-greased. The Y and Z Axes were not as fortunate. Both the screws and handles were severely pitted. New ones were made: The Y Axis Gib lock was originally under the saddle and up in the casting a bit (see photo below), which makes access difficult.

294545

But, there was a hole drilled in the side of the casting drilled for getting the gib lock hole drilled during manufacturing. I did a little figuring to make a longer Y-Axis Gib lock screw which used the drilled hole. I had to ream the casting hole to 33/64" (standard clearance for a 1/2" bolt) and turned a long shoulder bolt for the Gib lock. I suspect this was intended by the original designer, but was eliminated to save money; It sure makes locking the Y-Axis a lot easier (See Photo Below).

294544

The Z Axis Gib lock was just a really short version of the X and Y locks... all of the gib lock handle levers are drilled and reamed 10 degrees outward for ease of access.

294546

If I do a DRO, I will probably need to make an longer pair of X-Axis Gib Locks to clear the scale and the reader head; we shall see.
 

Attachments

  • 20190512_165004.jpg
    20190512_165004.jpg
    42.4 KB · Views: 0
I mounted my y and z on the other side. I used imaging scales and eventually I'll hook up the touch dro . It's not the most elegant, but it works
 
Back
Top