Cedarberg E-Z Hand Tapper - Teardown

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No clue how old this hand tapper is, but I couldn't find anything on the internet about its internals/guts, so I figured I'd make a post for record for anyone who is considering getting one or comparing to alternatives.

At present, if you search online for a hand tapper, you find:

• Cheapies from Amazon, with 3 jaw chuck, thin flat bar arm ($60-70 new)
• Generic cast arm/vise-grip base, made in China, sold by Grizzly/Ebay/Little Machine Shop (~$200-270 new)
• Cedarberg cast arm, no vise, made in USA, frickin expensive (~$500 new)

Grizzly has a number of review noting defects with spindle/collets/holding, and I asked Little Machine Shop about their option and they said it's dropshipped with no QC from them. So, I found a Cedarburg on Ebay with all but one collet present and bought for $280.

Here's how the Cedarburg is constructed:

1. Stainless steel base, 5/8" thick, (4) 1/4" counterbored holes at corner for bolting down, (4) 3/8" peg holes for a stop to keep your vise from spinning on the table
2. Cast aluminum arm, has two flats and (4) 3/8" holes for mounting to a post/column/wall
   1. Spindle runs through a bronze brushing with spiral grooves cut into it to store grease
   2. Spindle has a full-perimeter groove/detent near the bottom, into which a spring-loaded ball in an external set screw in the arm locks to hold it up in the air while your position your work. The ball is permanently trapped in the screw and cannot get lost in the screw is removed for cleaning.
3. Steel spindle/arm
   1. Knobs are plastic spinning freely between retaining rings on each end of each knob
4. Tap adapters are cut from lengths of hex rod, with a square bore cut into one end so the tap's square end locks into the adapter, the adapters have an 8-32 x 1/8" long hex set screw only to keep the tap from falling out of the adapters, the set screw is not needed for torque while tapping.
   1. The spindle has a hex bore, so all the torque while tapping is transferred by direct bearing between hex or square fit; no set screw
   2. The adapters are held vertically in the spindle from friction from a spring steel ring just inside the bore.
5. Tolerances:
   1. The spindle isn't tight in the bushing; there is just a little side to side play
   2. The adapters aren't tight in the spindle; there is a just a little side to side play
   3. The taps are tight in the adapters with no side to side play

You CAN still buy individual Cedarberg tap adapters online from MSC, but they aren't cheap ($35 each).

What makes the Cedarburg stand out?

• Bronze bushing with grease storage
  • Chinese version has no bushing per the Grizzly exploded parts diagram, just a hole bored in the arm casting
• All torque transmission from handle to tap is through direct bearing of steel within matching bores.
  • Chinese version uses a set screw to keep taps from rotating in a purely round bored adapter
  • The set screw screw is located at the very bottom of the adapter so the tap is barely embedded in the adapter and wants to wobble a lot.
  • The Cedarburg square bore is on the top of the adapter, so the tap is fully embedded in the entire length of the adapter for stability.
• Provision for wall mounting
  • Most people will probably just keep this on a shelf/table, but if you were truly cramped for working space at arm level you could wall mount it.