Typical Mill Rebuild Procedure

 

    

 This is a Kearney & Trecker No. 4 horizontal mill. The table has been removed for rigging purposes.

 

In this particular job the customer requires that we completely disassemble the entire machine, replace all worn out parts, bearings and seals, and strip the machine to bare metal and paint it to new machine quality.

 
 
    

 To the left you can see the removal of major components is nearly complete. These units will later be completely taken apart.

 

Here the column and spindle are all that remains of the original assembly. The spindle is left in the machine for set-up purposes in grinding the vertical ways perpendicular to it's axis. The column is now ready to go to the paint department for sandblasting and body work.

 

 Partial view of disassembled components.

   A view of more of the disassembled parts including the saddle. After cleaning and tagging all the parts a list will be developed of the required and recommended parts for rebuild. Price and availability will be specified.
   To the right you see the column after sandblasting and the initial body work. The column will next be primed and glazed with pure polyester resin for maximum hardness. Sanding will progress with finer and finer grits followed by another coat of epoxy primer. The column will then be ready for way grinding and scraping.
 

To the left the column ways are being ground on our Woodward way grinder. Not only must the ways be straight and parallel, but they must be perpendicular to the spindle vertically and horizontally.

 

 

To the right is pictured the column after way grinding and scraping once in each direction to improve bearing quality. The column is next laid on it's back and the back of the knee is hand scraped to mate with the face of the column.

The back of the knee has been scraped to mate with the column at this point and the top of the knee has been ground square with the back. The knee has not been sandblasted in this instance since we did not want to get any sand in the oil galleys. It will be stripped with paint remover by hand.
   

 

Below the machine is shown partially re-assembled.

The above photo depicts how the milling machine table was ground. The table being ground in this view is from a Bridgeport vertical mill. Any mill or drill marks in the table top are welded with nickel rod and the top of the table is lightly milled and ground flat. The sides are ground next. In the final set-up pictured here we grind the bottom flats and dovetails. The table thickness and distance across the dovetails are then measured to insure that they meet specifications.
 

 

 

To the right is a picture of the nearly complete machine.

 

 

To the left is a close-up view of the completed machine.

   

 

To the left is a picture of the completed machine.

 

 

 

To the right is a Van Norman
horizontal/vertical mill rebuilt in 1999

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