Drill Press Wobble on Chuck

[Chris TickTockParticipant @christicktock]

A wobbly drill press is a curse. I need a drill press for larger diameter stuff and my cheap old thing is what you would expect. It was fine drilling 1/2 inch holes when I fabricated a cage for my German Shepherd but little use drilling bearings as entry and exit holes will be different (let's leave reamers out of this for now).

Some drill presses can be adjusted others not so i thought I would ask you guys if you know of such a drill press that is both affordable and usable for fairly precise work. I do have a small jewelers drill cost £50, I modified the speed with another pulley and it has no wobble. So it may be possible on a larger machine?

Chris

Edited By Chris TickTock on 03/08/2020 16:44:26

[Chris TickTockParticipant @christicktock]

[John HaineParticipant @johnhaine32865]

It might help if you could be more precise as to what you mean by "wobble". Does it need its feet levelling (I guess not as that shouldn't affect the holes)? Is the drill running off centre ("runout&quot? Is the drill axis not parallel to the spindle axis? "Wobble" is vague and unless you can be precise it is hard to advise if any different machine might be adjusted to eliminate the problem you have.

[SillyOldDufferModerator @sillyoldduffer]

Depends on how bad it is, but a little technique may help get the best out of what you have.

First make an accurate centre-pop on the workpiece.

Then clamp the job tight in a machine vice, but don't bolt the vice down hard on the table. Leave just enough slack to allow it to shift sideways. (But firm enough to control a grab – my pillar drill is the most dangerous tool I own.)

Set the drill up so the tip of the drill is close to the work and aligned accurately with the centre-pop. (I use a dress pin with a big round plastic head stuck to the drill tip with plasticine as a wobbler).

Now the counter-intuitive bit. Might be expected holes will be more accurate if the workpiece is clamped firmly down. Don't. Instead, with the drill spinning at the speed suitable for it's diameter, feed the drill into the centre-pop and allow the work to align itself with the drill. You can see if the drill is being pulled off course as it engages – correct as necessary. Then go for it.

This works because a spinning drill prefers to stabilise on its axis, and the axis needn't be forced by tight accurate bearings. Provided the work is aligned with the spinning axis and the drill allowed to cut, it can be accurate. Think gyroscope. The secret is to let the workpiece go floppy and float into alignment. Takes a little practice.

Accurate drilling in a milling machine is easier. Mills are far more rigid than most pillar drills unless the bearings are trashed. Bolting down hard for accuracy works well on mills. And as a slightly inaccurate centre-pop makes things worse on a mill by pulling the drill off-axis, I don't bother with them. Instead, I start with a centre-drill or just go straight in with an ordinary one.

Dave

 

Edited By SillyOldDuffer on 03/08/2020 18:05:25

[Dave HalfordParticipant @davehalford22513]

Remove the chuck and check the spindle doesn't wobble.

If it's OK it's likely its a bad chuck.

If it doesn't drill square it's likely the table flexing due to the extra pressure needed for cutting bigger holes in metal. Some people up a hydraulic jack underneath the table to support it

[larry phelan 1Participant @larryphelan1]

What size do you need to drill ?

"Larger diameter" is a bit vague, like, "How long is a piece of string"

I have a 16 speed Taiwan 16 speed drill with a 5/8" chuck, which with the chuck removed, can handle 1" drills with no problem. After that I use the milling machine.

Horses for courses.

[Pete WhiteParticipant @petewhite15172]

Posted by SillyOldDuffer on 03/08/2020 18:03:46:

 

…….. "But firm enough to control a grab – my pillar drill is the most dangerous tool I own "

Made me smile, brought back memories of an old mate who tought me a lot, once said hold on Pete when I was out of order, I have seen a drilling machine make grown men cry. ….

Respect, even more for my big radial woodwork saw !

Sorry for the intrusion but we all need a smile these days

Pete

Edited By Pete White on 03/08/2020 19:59:45

[SillyOldDufferModerator @sillyoldduffer]

Posted by Pete White on 03/08/2020 19:58:46:

Posted by SillyOldDuffer on 03/08/2020 18:03:46:

…….. "But firm enough to control a grab – my pillar drill is the most dangerous tool I own "

,,,, I have seen a drilling machine make grown men cry. ….

Pete

Brilliant, I shall remember that one!

Dave

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