The symptom pattern

The drill is running, but the bit isn’t spinning true — there’s a visible wobble or run-out at the tip, whether you notice it as an oversized or ragged hole, a bit that seems to chatter as it enters the work, or just a shimmer at the tip when the drill is running with nothing touching it.

What’s actually happening

Axminster’s own troubleshooting table for the AP340PD pillar drill (and its AP325PD, AP700PD and AP540PD siblings, which share the same manual) names four separate causes for this, and only one of them is a mechanical wear issue. The other three are all about how the bit or the chuck is fitted, not what condition the machine is in.

Working through it

Start with the bit itself: take it out and check it’s actually straight, either by rolling it on a flat surface or watching it spin slowly in the chuck. A bent bit wobbles regardless of how well everything else on the drill is set up, and no adjustment to the chuck or spindle fixes it.

If the bit is straight, refit it and check it’s seated squarely and fully home in the chuck jaws — Axminster list this as its own separate cause from a bent bit, and it’s an easy thing to get slightly wrong without noticing.

Next, check the chuck itself rather than just the bit inside it: is the chuck correctly seated on the spindle’s taper? A chuck that isn’t properly installed on the spindle will wobble no matter how well the bit is fitted inside it.

Only once the bit and both fittings check out is it time to isolate the drill at the socket and feel for play in the spindle bearings by hand. This is the one cause on Axminster’s list that means a part rather than a refit.

The fix

Three of the four causes cost nothing: a straight replacement bit, or refitting the bit or chuck correctly, are the whole job. Worn spindle bearings are the exception, and they’re a modest part on a machine this size — but they’re also the last thing to check, not the first.

Verdict

Work through the bit and the two fittings before assuming the bearings. Most run-out on a pillar drill like this comes down to what’s clamped in what, not the condition of the spindle, and Axminster’s own table backs that up — three of the four named causes are free to put right, and only one needs buying anything.