History of the Craftsman 109 Lathe Models

aoresteen

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I have done a very deep dive into the Sears Craftsman 109 AA lathes. Here I will document them. All Craftsman 109 lathes were made by the Double A Products company of Ann Arbor, MI. I have broken them out by their bed types.

Generation I
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109.0701 Released 1938 Bed Vee to Vee 2.125" Spindle Nose size: 1/2" x 24 TPI Plain 4 step spindle pulley Branded: "Companion"
109.0702 Released 1941 Bed Vee to Vee 2.125" Spindle Nose size: 1/2" x 24 TPI Plain 4 Step spindle pulley Branded: "Dunlap"
109.0703 Released 1941 Bed Vee to Vee 2.125" Spindle Nose Size: 1/2" x 24 TPI Planetary Back Gear pulley Branded: "Dunlap"

Note 1: The 109.0702 is the same lathe as the 109.0703 except that the 109.0703 has thread cutting gears. The 109.0702 came without the gears but Craftsman sold a upgrade kit (Cat No. 99 PT 2083) that would convert the 109.0702 in a 109.0703 model.


Generation II
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109.20630 Released 1945 Bed Vee to Vee 2.50" Spindle Nose size: 1/2" x 20 TPI Planetary Back Gear pulley Branded: "Craftsman"
109.21270 Released 1949 Bed Vee to Vee 2.50" Spindle Nose size: 1/2" x 20 TPI Planetary Back Gear pulley Branded: "Craftsman"
109.21270 (Bronze/Gold Color) Released 1960 Bed Vee to Vee 2.50" Spindle Nose size: 1/2" x 20 TPI Planetary Back Gear pulley Branded: "Craftsman"

Note 2: The 109.21270 (Bronze/Gold Color) model is exactly the same as the original grey model. For the last 3 years of it's life (1960,1961,1962) it was sold in the
Bronze/Gold color.


Generation III
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109.21280 Released 1965ish ("Mid 1960s") Bed Vee & Square Step Size ??. Spindle Nose size: ?? - Planetary Back Gear pulley Branded: "Craftsman"


Sears Craftsman Lathe Chucks for the 109 Lathes:
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Four lathe chucks for the 109 AA lathes (plus various Jacobs "drill" chucks not listed here):

1/2" x 24 TPI:
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A. Cat No. 9 T 2137 - 4 Jaw independent 3" chuck 1/2" x 24


1/2" x 20 TPI:
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B. Cat No. 9 T 2157 - 4 Jaw 3" independent chuck 1/2" x 20 (111 21570 engraved on the chuck face)
C. Cat No. 9 T 2254 - 3 Jaw universal 2" chuck 1/2" x 20
D, Cat No. 9 T 2296 - 3 Jaw universal 3" chuck 1/2" x 20

I only have a type B chuck and do not know the engravings on the others. If anyone has one of the above A, C, or D chucks please post the number engraved on it.


Other Notes:
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3. There are many other model numbers that were used but they are simply duplicates of the above models. For example 109.2127 is the same as the 109.21270. I think they were used for different markets by Sears.

4. The head stocks, compounds, and tail stocks do NOT interchange between the three generations. When buying these parts, make sure you are buying the correct size for your model 109 lathe! Most eBay listings do not specify the vee to vee size!

5. The Gen I & II 109 spindles are all 0.550" OD and are hollow. They have a 0 Morse Taper opening in the nose. There is a 1/4" hole that runs through the spindle. These hollow spindles are known to bend! I have no information on the the 3rd gen spindle (part # 11111).

6. The Gen I 109 lathe spindles are not keyed (part # 3437); they have flat areas for set screws to secure the pulley & spacers. Gen II spindles are keyed (part# C-3657) and use a Woodruff key to secure the pulley. The spindle on my 109.0702 was not keyed and had a Gen II 1/2" x 20 TPI nose so it must have been a replacement.

7. A Gen I lathe can use a Gen II spindle if you find a Gen II keyed pulley (or back gear unit).

8. Replacement Generation II SOLID spindles made from 4140 high strength steel are available. Nose sizes are available in 1/2" x 20, 3/4" x 16, and 1" x 8. There is no evidence of any solid 4140 steel spindle ever bending.

9. The Sears recommended motor is a 1725 or 1750 RPM 1/4 HP or 1/3 HP motor. With the standard pulley the lowest speed possible is 600 RPM. With the "Planetary" back gear unit, the lowest speed is around 120 RPM. This makes the 109 AA lathes way too fast to cut steel threads.

10. The most serious issue with the 109 AA lathes is that they are just too fast! A countershaft (called "Jack Shaft" in the Sears catalogs) set up is needed to slow the 109 lathes down to 50 RPM. While there are a few references to a Craftsman 109 countershaft (Jack Shaft) system, they are rare and hard to find. You will most likely have to cobble together your own countershaft setup.

11. Another solution is to install a 3 phase motor with a VFD to slow it down.


I am sure that I've made a few errors here so if you have more info please post it! Info on the 109.21280 is very scarce! Thanks!
 
Very thorough! I had no idea a 1"x 8 spindle was available.
Another low/zero cost variable speed option would be to take the motor and controller from a used treadmill
I believe the change gears for the Atlas 6" lathe are identical to those for the 109
-M
 
I have also read that the change gears from the 109 fit the Atlas 6" but I have never tested it as I have never been near one. I'd like to hear from an Atlas 6" owner that has used 109 gears in the Atlas.

I need to explore the treadmill motor setup but my Commander will not let me pull her tread mill apart :) .
 
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