How to Change the Arbor on a Drill Press: Swap It Without Wrecking the Spindle
Your chuck runs true but you need a different taper, or the arbor itself is nicked and the chuck wobbles no matter how clean you get it. Either way, learning how to change the arbor on a drill press is worth the fifteen minutes, and the job is simpler than the forum horror stories suggest, as long as you confirm one thing first: that your press actually has a removable arbor.
The arbor is the two taper connector between the spindle and the chuck. The top end is a Morse taper that seats up into the quill, and the bottom end is a Jacobs taper that the chuck grips. On presses built this way, the arbor drops out and swaps easily. On presses where the taper is machined into the spindle nose, there is no separate arbor to change, and that distinction decides everything.
First, confirm you have a removable arbor
Unplug the press. Look for an elongated hole through the quill above the chuck, called the spindle access window or drift slot. If it is there, you have a removable Morse taper arbor you can drift out. If the nose is a solid taper with no slot, the Jacobs taper is integral to the spindle, and there is no arbor to change, only a chuck to swap or a spindle to replace.
Check your model number and manual to confirm the Morse taper size, commonly MT2 on mid size and floor presses, since you will need the matching size for the new arbor.
Remove the old arbor and chuck
With a removable arbor, the arbor and chuck usually come out together as one unit.
- Lower the quill with the feed handle until the drift slot is fully exposed, then lock the quill.
- Put a block of wood or a folded towel on the table under the chuck to catch the assembly.
- Insert a taper drift key into the slot, flat side up so its wedge shape bears against the top of the arbor.
- Give the drift a sharp mallet tap. The arbor breaks free of the Morse taper and drops with the chuck onto your block.
Do not use a screwdriver as a drift. Its shape does not match the slot and it chews the spindle. A proper drift is cheap and made for this.
Separate the chuck from the old arbor
If you are reusing the chuck, separate it from the arbor on the bench. Clamp the arbor gently in a vise with soft jaws, then drive the chuck off the Jacobs taper with a pair of wedges between the chuck and the arbor shoulder. A dedicated JT6 and JT33 drill chuck removal wedge set does this cleanly and gives you even pressure so the chuck comes off square. If the fit is tight, tap the jaws down to open a little room for the wedges to seat.
Fit the new arbor
Match the new arbor to both tapers: the Morse taper that fits your quill (such as MT2) and the Jacobs taper that fits your chuck (such as JT33). An arbor labeled MT2 to JT33 means exactly that pairing.
Cleanliness is the whole game with tapers. Wipe the Morse taper on the new arbor and the socket in the quill bone dry, removing every trace of oil, grit, and rust. Seat the arbor into the quill with one firm push, or a light tap using a wood block against the arbor end. The taper self holds by friction, so there is no bolt or drawbar on most presses.
Then mount the chuck on the arbor’s Jacobs taper: clean both surfaces dry, close the jaws, rest them on a wood block, and push straight down firmly to seat the chuck.
Check your work
Spin the spindle by hand and watch the bit tip, or use an indicator if you have one. If it runs true, you are done. If it wobbles, the taper is dirty or nicked, so pull it, clean it again, and check for burrs. Never seat or test an arbor by running the motor down into the table, since that hammers the taper and the bearings.
When there is no arbor to change
If your press has an integral Jacobs taper nose, changing the arbor is not possible, because there is no separate arbor. Your options are to swap the chuck on that fixed taper, or, if the taper itself is damaged, replace the whole spindle assembly. Do not try to force a Morse taper arbor against a nose that has no socket for it.
The verdict
Changing a drill press arbor is quick and low risk once you confirm the press has a removable one.
- Look for the drift slot first; no slot usually means an integral taper and no arbor to change.
- Drift the arbor and chuck out together, using a real taper drift, never a screwdriver.
- Match the new arbor to both your Morse taper and your chuck’s Jacobs taper.
- Seat every taper bone dry and check runout by hand before running the motor.
FAQ
How do I know if my drill press has a removable arbor? Look for an elongated hole, the drift slot, through the quill above the chuck. If it is there, the arbor is removable with a drift. A solid taper nose with no slot means the taper is integral to the spindle.
What size arbor does my drill press need? Match two tapers: the Morse taper that fits your quill, often MT2, and the Jacobs taper that fits your chuck, often JT33. Your model number and manual confirm the Morse taper size.
What tool removes a drill press arbor? A taper drift key, which is a flat wedge shaped tool you insert into the drift slot and tap with a mallet. It pushes the arbor out of the Morse taper cleanly, unlike a screwdriver, which damages the slot.
Can I reuse my chuck with a new arbor? Yes, if the chuck is good. Separate the chuck from the old arbor with wedges, then mount it on the new arbor’s Jacobs taper, cleaning both surfaces bone dry before seating.
Why does my bit still wobble after changing the arbor? Almost always a dirty or nicked taper. Pull the arbor, clean the Morse taper and the quill socket until they are spotless and dry, remove any burrs, and reseat it with a firm tap on a wood block.
Does a drill press arbor need a drawbar? Most drill presses hold the arbor by friction alone, with no drawbar. That is fine for normal drilling, though side loads can loosen it, so seat it well and reseat if it works loose.
My press has no drift slot. How do I change the arbor? You cannot, because the taper is integral to the spindle nose. You can swap the chuck on that fixed taper, or replace the entire spindle if the taper is damaged.
References
- Jacobs Chuck Manufacturing, Mounting and Removing Chucks (jacobschuck.com)
- VintageMachinery.org Knowledge Base, arbor and taper guidance (vintagemachinery.org)
- Machinery’s Handbook, Morse taper specifications (Industrial Press)
