Original Craftsman Ball-Shaped Right Angle Drill Adapter - Comparison to Later Vintage Options

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I picked up a few vintage right angle adapters before I got an actual right angle drill, and they were all wobbly and erratic. For curiosity's sake, I decided to buy the original 1950's craftsman adapter which is a single, solid aluminum housing and was advertised as "no oiling" which I was really hoping meant ball bearings. Not the case, unfortunately, but much better constructed than the others.

1950's Craftsman adapter (halves or doubles speed depending on orientation):

• No handle, but the shape fits well in your fist grip and allow you to apply pressure in line with the spindle without your fingers hitting the drill or chuck.
• Steel gears, fixed to shafts with taper pins.
• The gears are very well axially aligned on the shafts, so that between the flats of the gear body and the flats of the spindle outside the bushing, the shaft has only thousandths of axial play instead of around 1/16" - 3/32" like the others.
• The whole spindle/bushing assemblies have male threads and screw into the housing with snap ring pliers, and are then locked in place by a tapered set screw landing in a drilled hole in the assembly. Combined with the shaft axial alignment mentioned above, the gear tooth meshing stays practically perfect, like in a press-fit ball bearing.
• Bull gear shaft is 3/8" diameter in a 1 1/4" long bronze bushing - I can't feel any radial play/wobble.
• Pinion gear shaft is 1/4" diameter in a 3/4" long bronze bushing - has some radial play/wobble, but better than the other models. Still, this is the weak point, as the small shaft and short bushing will wear faster.
• Housing was packed full of grease, all still quite wet. When I received the adapter, a little oil has leaked out of both bushings, so the lubrication was working great.
• Both shafts are threaded 1/4" female and have 1/8" holes in the perimeter for holding them steady with an allen wrench or spanner wrench to remove anything threaded into them. You'll need 1/4" to 3/8" couplings to direct mount to a drill or add a keyed chuck.

This model takes up more more space and offsets a drill bit farther from the work surface than other vintage models, but is is by far the sturdiest and most reliable.

 

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Later vintage models:

The other vintage models have halved plastic or aluminum housings held together by screws. Their shafts ride in 1 or two bronze bushings (but are larger at 3/8" diameter or more). The shafts have wobble in the bushings and the bushings wobble in the housing because the housings are only cast on the interior, not machined. They will only have smaller dabs of grease on the gears and the bushings will be dry. The shafts have noticeable axial play, so I shimmed mine with fiber washers. However, they may have 3/8" male and female threads instead of 1/4" from easy mounting to a 3/8" drill or chuck without needing a 1/4" to 3/8" coupling.

 

[d42jeep]

Mine is the early one. No chuck though.
-Don