Acceptable Drill Press Runout?

You might want to read

which is now 10 years old but holds up well. Here is the relevant passage:

SPINDLE RUNOUT ==============

To check spindle runout, you will need some measuring equipment, plus some tooling to remove the chuck. I use a 2MT drift pin and a chunk of type metal to remove the chuck. I use a magnetic base and a dial test indicator to make the runout measurement.

Remove the drill chuck, insert the test indicator, and rotate the spindle by hand. Note the extreme values. Their difference is total indicated runout, or TIR. A good spindle will have less than .0005" runout. A bad one can have over 1/32" runout. My old one had .007" which isn't that bad but I wanted better for metal working. Look for a machine with less than .001" TIR on the internal spindle taper.

Grant

Good advice below...

You may also find that the Morse Taper adapter for that chuck (Presuming it has one and not a simple Jacobs' Taper only...) is bent or not seated properly.

For wood, it's probably fine as I don't know anyone who measures closer than

1/64" (0.016") on wood applications but I guess it all depends...

For metal, I'd fix / replace it. That's a lot of runout for metal IMHO.

I hope you get other replies, but I'd buy piece of drill rod that's about as large in diameter as your chuck will take, let's say 1/2" diameter. MSC and everyone else sells it in 18" and 3 foot sections. You might even buy a drill rod blank. Buy it or cut it so that about 3 inches sticks out of the chuck when it's in place. Measure the run out both close to the chuck and then about 3 inches away. I guess I'd like to see less than .001 in either case, but I don't really know what is possible with your particular machine. Can't you call the seller and ask them what is the spec? Establishing some sort of contact with them is a good idea right now anyway. If you talk politely to the folks on the phone, assuming that you can find some, they may even open up and offer some info you don't have.

Come to think of it, have you tried several drill bits to eliminate the possibility of a bent one?

Also: an old machinist taught me that you ALWAYS tighten the chuck using ALL 3 holes for the key!!!! You snug it up with the first hole, then crank harder on the other 2. Then maybe give the first hole another tweak.

Pete Stanaitis

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Runout of the chuck shell doesn't mean anything - it's the tool held in the chuck you should be concerned with. Get a dowel pin from the hardware store, the longer the better. Check the runout near the chuck jaws and at the end of the pin. Several thousandths might be acceptable, ten would not. You'll have to check with Jet to see what they accept.

I don't know what the details of that drill press are, but it's almost certainly a male Jacobs taper to seat the chuck. Whether that taper is on a solid spindle, or on an arbor inserted into a female Morse taper in your spindle I can't say. If it's the latter, pull the arbor out of the spindle taper and clean them well. Check for burrs or imbedded chips. Test the bore with your indicator. Reinstall the arbor and check the dowel pin again. You can do the same tests with the Jacobs taper, but you may have a tough time getting the chuck off without the proper wedges.

It's more likely to be bent arbor or chips or poor seating in the Morse taper. It's a bit less likely to be chips or poor seating on the Jacobs taper, since that was probably done at the factory. It's least likely to be a bent spindle or one with a bad Morse taper or bearings.

John Martin

Jones, From your post yesterday and today, it is clear to me that you have a 25% er. Let me explain. When you buy Chinese there is a 25% chance that the product you have bought is faulty. Now this is OK because you just paid 50% of the going rate for the product. Of course, it is not so OK if you happen to be a 25% er, because you now have the hassle of dealing with the crap you just bought, but there it is.

Your drill press will most likely host a Morse Taper spindle. It is most likely to be a number 2, but it could be a number 3. In any case you have a spindle adapter that adapts the MT 2 taper to the Jacobs taper Number 0 or

1 that mounts the (1/2") Jacobs chuck. This is where your fault is the tapers in the chuck and on the adapters do not exactly match. That is why it keeps coming loose and when it does seem to jam it is not straight. Please return those parts to wherever they came from and get good ones. This can easily be tested using prussian blue grease. Steve

I think you have the same problem as yesterday. A chuck that won't stay attached and heavy runout are both symptoms of the same problem. These tapers do not take well to side loads, something is not running true. A new Jet press should be in the couple thousandths total runout max. Less than .001 is decent.

Undo the belt(s), pop the chuck out of the drill press, measure the runout to the inside of the spindle (should be a #2MT). Should be around .001" If you can take the chuck off the adapter, do so. Insert the adapter, measure runout on the MT side of the adapter, then the Jacobs taper side of the adapter. All should be .001" or less. Put the chuck on the adapter, insert a decent chunk of heavy drill rod, tighten all 3 positions, see what you get at the mouth of the chuck and several inches away. On a new mid range machine, I'd expect runout of perhaps .003" at

3" from chuck.

If you have any local friends that will share, see if you can borrow a chuck with suitable adapter, might save you some time.

I'd be look> Thanks again to all who advised me on my drill press problem yesterday. >

Thank you, everyone who replied. I'm really getting an education here.

Since I'm still a bit fuzzy on terminology and so on, I plan to compile all your suggestions into one document, thrash it all out to see what I've got, and report back.

Again, thank you all for taking the time and trouble to answer. I've learned a lot already.

Jones.

When you put it all together, why don't you turn off that "do not archive" option? That way, maybe the next guy with the same problem will be able to read about it in the archives rather than asking some of the same questions.

John Martin

I would just purchase another one.

xman

If he hadn't mentioned the mortising rig that he wants to get, I'd agree with the 1/64"...however, once you start talking about the mortise rigs, you need MUCH closer TIR... just a couple thou at most. The biggest reason for this is that you will have a drill spinning INSIDE of a square chisel that is being held, long way around, by the quill. That gives many places for interference to add up.

Mike

the jacob's chuck site tells you to measure runout by holding a drill blank that is 1/2 the chuck's capacity in the chuck and measuring 1.5 inches from the chuck body, runout less than .015

a cheaper chuck and a cheap drill press could give you more

replying to John Martin, Rob Lawrence wrote: This. I get around 0.002 runout at full spindle extension on my jet drill press at the drill bit shank, but the chuck itself wobbles visibly. While this may not bode well for vibration, it wouldn't serve anything to measure runout here by the key holes. I get 0.002 at the spindle, and less than 0.001 at the arbor, which means, in short that it's fine, or needs a new chuck that isn't made by Jet :D

The Jet drill chuck may have been a lot better when brand new, but if you have ever had a drill bit spin in the chuck, it can deform the jaws a little and increase the runout.

And -- is the arbor a permanent part of your drill press, or is it a Morse taper arbor which you purchase to fit the drill chuck and the spindle? I've seen both types, and prefer the latter. You can buy a higher quality arbor if you need more precision -- assuming that the socket in the spindle has little enough runout. (And, it does not take much debris in the socket to make a very good arbor run out. :-)

Personally, I prefer the Albrecht keyless chucks which tend to be very good when new and to hold up quite well afterwards.

And -- the acceptable runout varies with the size of the drill bit. A #80 bit (0.0135" diameter) does not like pretty much any runout that you can measure -- and even more so if it happens to be a solid carbide bit of that size. :-) (And you can't hold that small a bit in a

1/2" drill chuck -- even one by Albrecht. But they make smaller ones appropriate for smaller drill presses. I have a 1/8" Albrecht chuck on my Cameron sensitive drill press.

The biggest problem with that small a bit in the 1/8" Albrecht chuck is that it is hard to see to keep the bit centered while closing the chuck -- and at that size, there is little feel. I rotate the spindle by hand on the pulley on the top and look for wobble.

The one place where a keyless chuck like the Albrecht is *not* a good idea is when you are using a left-handed bit to drill out a sheared off screw -- and have a drill press which will run in reverse. (There are special versions of the Albrecht chucks which have the ability to lock once closed -- but of course that is not as convenient for common use.

Is it the chuck ? is it the taper the chuck uses to mount with - dirty ? Or the bearings (bushings) warn ?

Check into the basics before you replace anything.

Lathe chucks can wobble if the mount isn't clean and the heal of the chuck fits firmly against the lathe.

Dad had a chip of brass in a thread and the chuck on the lathe didn't run true. Cleaning it with a scribe I found many chips inside the chuck from a previous job.

Might be as simple as that.

Mart> reply> This. I get around 0.002 runout at full spindle extension on my jet drill