How to fix the wobble on my drill press?

[sploo]

I've got a Warco 2F pillar drill (MT2 spindle taper). It's fitted with a Jacobs model 34-06 (#06295) chuck (6JT mount), with a Jacobs A0206 2MT/6JT arbor.

I recently noticed that I was getting a pretty severe wobble at the tip of drill bits. I've not had an impact or any other damage to the drill or chuck so I'm not quite sure what's caused it.

I set up a dial gauge to try to work out where the problem is, and took measurements on the arbor above the chuck, the bottom of the chuck (between the jaws and the holes for the key) and along the length of various bolts or other smooth rods held in the chuck:

In the image above, the section right at the top is the bearing. 8mm down (on the arbor - point A) I'm getting about 0.05mm runout. Near the bottom of the chuck (about 82mm down - point B) I'm getting 0.13mm. With rods protruding anything from ~40mm (point C) to 80mm from the jaws I'm seeing between 0.15 and 0.28mm of runout (all figures with the drill running). It's enough to be easily visible, and you can see the dial gauge needle "pumping" back and forth. In old money (if my calculations are correct) that's between 6 and 11 thou runout at the tip.

Given that I'm getting 0.13mm of runout at the bottom of the chuck (it's a visible 'wobble' at point B) I don't think the issue is with the chuck jaws - it's the chuck itself that's wobbling.

I've tried a few gentle taps with a hammer to see if that would straighten it on the arbor - no luck. I've also tried pressing the chuck into a block of wood to see if it's slipped on the arbor - still no change.

I'm at a bit of a loss now. I could get some wedges (http://www.jacobschuck.com/accessories/ ... n-6jt.html) and/or try to drill through the bottom of the chuck to try to remove it from the arbor (http://www.jacobschuck.com/drill-chuck-removal-guide) as I guess I could then check the runout on the arbor (and hopefully eliminate that as the problem).

Anyone got any other advice on fixing the wobble, or removing the chuck?

 

[flh801978]

Can you remove the chuck from the quill?
If you drop the quill there might be a slot for you to use a wedge to remove the arbour
Then you can knock out the arbour from the chuck by opening chuck fully and using a drift


Ian

 

[Myfordman]

Then you can knock out the arbour from the chuck by opening chuck fully and using a drift


Ian

Only once he has drilled out the back of the chuck to allow the drift to contact the arbour.

In my experience, drills don't sudden develop runout by themselves. It is usually because a chuck has been taken off/fallen off and not cleaned and refitted correctly or that there has been some snarl up in use and the arbour has been bent.
Progressive increase in runout over time can be bearing wear too but that can be felt when the machine is stationary.

 

[sploo]

Can you remove the chuck from the quill?
If you drop the quill there might be a slot for you to use a wedge to remove the arbour
Then you can knock out the arbour from the chuck by opening chuck fully and using a drift

The daft thing is that until I started Googling for info last night I'd never heard of a drill drift . Having taken a look at the machine this morning, it does indeed have a slot for a drift, so I've ordered one, along with a pair of wedges (gives me both options I guess).

Only once he has drilled out the back of the chuck to allow the drift to contact the arbour.

In my experience, drills don't sudden develop runout by themselves. It is usually because a chuck has been taken off/fallen off and not cleaned and refitted correctly or that there has been some snarl up in use and the arbour has been bent.
Progressive increase in runout over time can be bearing wear too but that can be felt when the machine is stationary.

It had occurred to me that, in the absence of a lathe, it might actually be easiest to drill a hole in the chuck by mounting a fixed drill bit vertically on the drill press table, and gently lowering the chuck onto it whilst it's still on the machine. The runout might be small enough at that area, such that I wouldn't snap a small metal drill bit.

That said, if the drift works then I can obviously take it out to try to drill it - assuming the wedges don't work.

If I lower the quill then there is some lateral movement, but as the runout is present even without lowering it I'm assuming it's arbor or chuck. There doesn't appear to be any lateral play with it up, so I'll assume the bearing is OK.

I haven't used a long bit in a while, so it's possible that something's knocked it out of alignment and I hadn't noticed (with short bits), but I can't think of a recent accident/impact.

With luck I'll be able to get the chuck off with the wedges and will be able to check the arbor separately. It could all do with a clean anyway.

Thanks both for the info.

 

[sploo]

Well, not quite what I intended, but I've received the drift and wedges, and set about trying to use the wedges to remove the chuck + arbor from the drill.

If you look at the image in my first post, I assumed that the larger diameter area (upwards from the horizontal line in the "A" on the photo) was part of the arbor. As such, I used the wedges between that and the top of the chuck. I was surprised that I needed to pad it with a little shim as the distance was larger than the gap.

A couple of light taps and the chuck came right off ... with the arbor

Turns out, that top section is actually part of the drill press (into which you insert the arbor), so I'd kinda just done the job of a drill drift, albeit in the wrong place. Anyway, it was easy to remove so I'm pretty certain there's no damage done.

The dark thinner diameter section of the arbor isn't suitable for the wedges, so I couldn't use those to remove the chuck from the arbor unless I drilled a hole for a pin through the arbor. It does seem a bit daft as it's a Jacobs 6JT arbor, and I've got #6 wedges - but clearly they're not compatible. A smaller wedge wouldn't fit around the arbor diameter, so I'm pretty certain I got the right thing.

It does however look as though there's already a ~3mm hole in the chuck (I got it from new, so it's not been drilled by someone else). I didn't have time last night, but it may be that I can already access the end of the arbor, so will look at trying to press it out later.

 

[dickm]

On the basis of my experience, good luck
(Those JT tapers into chucks can be a total pita)

 

[sploo]

On the basis of my experience, good luck
(Those JT tapers into chucks can be a total pita)

That's the gist I've had from others. I may be in for a hard time!

Once I (hopefully) get it separated, what should I do to the parts before reassembly? Clean up obviously, but oil, no oil, something else?

 

[CHJ]

Once I (hopefully) get it separated, what should I do to the parts before reassembly? Clean up obviously, but oil, no oil, something else?

I'm sorry to say this but what do you hope to achieve by removing the chuck from the JT taper.

The chuck is obviously firmly attached to the mandrel taper, it's been there a long time and was obviously a good fit in the first instance else it would not have gripped, you don't need to remove the chuck body from the taper to dismantle the chuck. Dismantling the chuck will not change any run-out seen at point B as that is part of the main chuck body and runs concentric with the JT taper.

http://www.beautifuliron.com/jacobs.htm

You say you have run out at point A on the drill quill, you need to investigate why you have this if the run-out is a new occurrence.
I see you have the dial gauge running on a threaded bolt in your image, with the threads held in the jaws, with the best will in the world this is never going to run true, standard bolts are just not made to that sort of accuracy, ground silver steel rod maybe, bolts never.

I suspect the bulk of your problems are centred about the quill run-out or the Morse taper fit into the quill sleeve.

 

[sploo]

Once I (hopefully) get it separated, what should I do to the parts before reassembly? Clean up obviously, but oil, no oil, something else?

I'm sorry to say this but what do you hope to achieve by removing the chuck from the JT taper.

The chuck is obviously firmly attached to the mandrel taper, it's been there a long time and was obviously a good fit in the first instance else it would not have gripped, you don't need to remove the chuck body from the taper to dismantle the chuck. Dismantling the chuck will not change any run-out seen at point B as that is part of the main chuck body and runs concentric with the JT taper.

http://www.beautifuliron.com/jacobs.htm

You say you have run out at point A on the drill quill, you need to investigate why you have this if the run-out is a new occurrence.
I see you have the dial gauge running on a threaded bolt in your image, with the threads held in the jaws, with the best will in the world this is never going to run true, standard bolts are just not made to that sort of accuracy, ground silver steel rod maybe, bolts never.

I suspect the bulk of your problems are centred about the quill run-out or the Morse taper fit into the quill sleeve.

Yea, a bolt wasn't ideal. I don't have any suitable rod stock though. I did try a few different items - including a long drill bit (putting the dial gauge on a smooth section near the top of course).

But, would 0.05mm of runout at the quill be indicative of the problem on a drill bit in the chuck (i.e. the chuck might be "off" on the arbor?)

I was hoping to get just the arbor into the quill and check that for runout, and if good, try to remount the chuck. At least, that was my plan.

The link above is useful though, and confirms that what I saw inside the chuck is indeed an access hole. Other resources I've found indicate that there wouldn't be a hole ready drilled.

 

[CHJ]

The chuck is not going to have moved on the JT taper, if it had it would have fallen off on the drill table. The Morse taper may have moved in the drill quill a fraction until such time as the tang wedged against the rotation.

 

[sploo]

The chuck is not going to have moved on the JT taper, if it had it would have fallen off on the drill table. The Morse taper may have moved in the drill quill a fraction until such time as the tang wedged against the rotation.

Sadly you're almost certainly right, but that (a slightly tilted chuck) would've been the "easy" solution.

Would you suggest I just clean the arbor + chuck and try to refit it? Or is there anything else I could do (I'll check the bearing, but it appeared OK).

 

[CHJ]

Clean out the drive shaft taper with some stiff rag soaked in white spirit on the end of a split stick, likewise wipe off the Morse taper. and reseat the Morse arbour.


When you run the drill, Press the side of the protruding quill hard with a piece of scrap wood so that in effect you are trying to push the machine sideways.

Do you still see wobble, if not check for an adjustment grub screw on the side of the quill housing and remove any excess side play in the quill.

If quill is firm and no movement then likewise with a Vee notched stick press the side of the Rotating Shaft (not the chuck arbour you might release it) to see if wobble disappears.

 

[sploo]

Clean out the drive shaft taper with some stiff rag soaked in white spirit on the end of a split stick, likewise wipe off the Morse taper. and reseat the Morse arbour.


When you run the drill, Press the side of the protruding quill hard with a piece of scrap wood so that in effect you are trying to push the machine sideways.

Do you still see wobble, if not check for an adjustment grub screw on the side of the quill housing and remove any excess side ply in the quill.

If quill is firm and no movement then likewise with a Vee notched stick press the side of the Rotating Shaft (not the chuck arbour you might release it) to see if wobble disappears.

Very clear - many thanks. I'll try that tonight or over the weekend.

 

[sploo]

Got a reasonable result; there is an adjustment screw for the quill on the side of the machine. I couldn't tighten it too much without stopping the quill from lowering, but it's reduced side-to-side movement a bit.

I gave the chuck, arbor and shaft taper a good clean and reseated it.

Using a stick on the quill and shaft didn't make much (if any difference) to the runout, but the cleaning and reseating does seem to have improved things.

Using a good quality forstner bit (no idea why I didn't think of it earlier) as a shaft for checking runout, I'm now down to 0.10 to 0.15mm runout with a bit sticking 6cm+ out of the chuck.

Previously you could definitely see the tip on a drill bit wobbling, but now it's very difficult to detect anything (with the same bit as before), and the machine is drilling well.

Good result, and many thanks all for the advice!

 

[CHJ]

Glad it's sorted to your satisfaction, try not to over analyse a suddenly noticed problem, unless something obvious has broken try the simple things.

Although purchasing odd tools like removal wedges is not a great expenditure and they will last a lifetime, as long as you can find them in 20yrs time that is, a couple of scrap hard wood, one time use ones usually work and a lot of home workshop maintenance jobs can be done with simple work around bits from the scrap box.

 

[sploo]

Glad it's sorted to your satisfaction, try not to over analyse a suddenly noticed problem, unless something obvious has broken try the simple things.

Although purchasing odd tools like removal wedges is not a great expenditure and they will last a lifetime, as long as you can find them in 20yrs time that is, a couple of scrap hard wood, one time use ones usually work and a lot of home workshop maintenance jobs can be done with simple work around bits from the scrap box.

Thanks. Yea - given how easy it was to remove, I suspect a drill drift made from a slot of hardwood might have done the job. They were cheap parts and are now in a cabinet, so no wallet harm done.