Advertisements

Shortening a 2MT-to-1MT Morse Taper Sleeve

The hulking 1/2 inch Jacobs chuck is grossly oversized for most of the holes I poke in things spinning in the lathe. I already have several smaller Jacobs chucks for the Sherline’s 1 MT spindle, so I got some Morse Taper Sleeve Adapters for the mini-lathe’s 2MT tailstock. They’re longer than the “short” 2MT dead center:

1MT to 2MT adapter - vs 2MT dead center

1MT to 2MT adapter – vs 2MT dead center

Because they’re longer, the tailstock ram loses nearly an inch of travel it can’t afford.

So I hacksawed the taper just beyond the opening at the tang and faced off the ragged end:

1MT to 2MT adapter - facing

1MT to 2MT adapter – facing

The steady rest jaws don’t match the Morse taper angle, but they’re way better than assuming the nose of the Jacob chuck can hold such an ungainly affair.

The short 1MT taper on the drill chuck doesn’t extend to the opening: when it’s firmly pushed into the socket, there’s no simple way to eject it. So, drill a small hole for a pin punch to pop it out:

1MT to 2MT adapter - center drilling

1MT to 2MT adapter – center drilling

I hate hammering on tooling, which means I must eventually enlarge the hole to clear a 5 mm bolt, make a square-ish nut to fit inside the slot, and gimmick up a plug for the 1/4-20 socket in the 1MT taper (used by the Sherline mill drawbar). More work than I want to take on right now, but it’ll provide some Quality Shop Time.

If the truth be known, I also got a 3/8-16 thread to 2MT adapter for the mid-size Jacobs chuck seen in the pictures, thus eliminating the thread-to-1MT adapter and plugging the chuck directly into the tailstock. The 1MT adapter will come in handy for the least Jacobs chuck; although LMS has a 0JT-to-2MT adapter, the less I monkey with that tiny taper, the better off we’ll both be.

Advertisements

,

  1. #1 by RCPete on 2017-10-20 - 12:29

    Is there enough steel left to tap the adapter? The square nut sounds like a pain.

    On the 1/4-20 plug, a set screw would do the job. The hex socket shouldn’t get bunged up. I think. [grin]

    • #2 by Ed on 2017-10-21 - 09:53

      There’s a scant 1.5 mm of steel left: the top of the tang didn’t quite overlap the bottom of the through hole. If I’d been thinking even slightly ahead, I’d have spared a few ugly millimeters of that tang.

      Despite my proclivities, a brass insert bedded in epoxy probably wouldn’t have enough strength for the job. Fitting a weird nut into the space available will serve as penance.

Spam comments vanish. Comment moderation may cause a delay.

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s