THIS IS NOT AN ENTIRE DRILL PRESS. IT IS A SLOW SPEED INTERMEDIATE PULLEY AND ADAPER ONLY.  Example drill press shown to illustrate fit and function only.  No belts included.

Slow speed drive system fits entirely inside belt cover on my Walker Turner 900 drill press shown in first photo (NO DRILL PRESS INCLUDED).  Reduces RPM at chuck.  Slower cutting speeds work better for metals.  Larger diameter cutters such as hole saws, paddle and Forstner bits cut better with less heat when turned at proper speeds.  Small diameter bits require higher speeds.  This pulley while capable of cutting your final output speed in 1/2 is also capable of doubling it making bits under 1/8" must less fragile.    Add about $350 value to your vintage American iron.  

1) Your machine MUST have a column with 2.5" bore to accept the ABS adapter.  (Shown in photo, caliper upside down).  This is typical of many drill presses with 2.750" columns.  If you have a different size, please contact me.  Note, adapter will fit bores + or - .032" of the indicated size.
  
2) The column must be capable of protruding through the top of the head casting. (See caliper photo.)

3) Made for 4 groove pulley system requiring 1/2" belts or 4L belts. (Converts your 4 speed into a 12 speed with both slower and faster speeds.)

4) Flipping the motor drive pulley over is required.  All of them I have seen can be flipped without machining.  I have not seen yours.

5) Adjusting the head height on the column is required to line up belts.

6) Your belt guard (if so equipped) bottom or base plate must not cover the drill press column. If it does, a hole must be cut approximately 3" in diameter to reveal the tube opening.

This item includes: Metal pulley loaded with ball bearings, pivot yoke, bronze pivot bushing and additive manufacturing ABS column adapter machined to accept a bronze bushing.  This item is made by me including sourced and modified parts.  The drill press, belts and my hand are props used to show application of slow speed update kit and not included.

Don't buy this hoping it will fit.  MEASURE THE BORE of your column.  If your bore is different, please send me a photos of your drill press, caliper measurements and model of drill press.  I just might make a special one for you.  Look in my store for many other sizes.

Following information is not warranted.  Provided as a record of my experience with my machines and sourced information.

Drill Presses I have installed this assembly on:  (I can't own them all, many from the 30's through the 70's used this size column tube)

Delta Rockwell 15-207 15"  (in photo's) Belts: Fenner 4L 5:1 quill 39 links, motor 34 links.  V-Belt quill 4L290, motor 4L245 5.5:1
Delta 15-017 15"
Atlas "73"  15" (probably all similar models same tube)

Customers report:  
Delta DP220 - Customer reports using 24" belt on front and 26" belt on rear.

Likely Candidates: Due to 2.75" OD columns meaning likely 2.5" ID Tubes.  MEASURE!

Drill Presses I have measured:
Atlas "73", "74" 15" (and all similar models)  2.5" id
Craftsman DP100 & 150 LATE MODELS  2.5" id (Only top of column is bored to size, check both ends to verify proper installation of column)
Craftsman DP100 & 150 EARLY MODELS 2.375" ID on Top of properly installed column.  See other listings.
Delta DP-220 15"  ID 2.418" (Buy 2.375" model in other listing. Internal collet expands to lock tight)
Delta 15-091 15"
Delta Rockwell DP-211 14"
Delta Rockwell 15-655
And Many Others

DO NOT RELY ON ABOVE LISTS.  It is up to you to MEASURE YOUR TUBE ID.  This item fits 2.5" tube ID.  Let me know if you need something different.