How is drill press chuck runout (TIR) specifically defined?

Scott H

Scott
User
I am idly looking around and I noticed that a lot of chucks quote a TIR value but I am having trouble getting the official definition for where that is measured when it's quoted on a product page as just "TIR".

Am I to interpret that as measured on the shank of a bit right below the chuck jaws? Or farther down the bit some specific distance? I assume it's not on the chuck body itself because that doesn't tell you anything about the jaws.

I have a dial indicator and some precision ground drill rod so it would be interesting to compare to what I have currently.
 

pop-pop

Man with many vises
User
My guess would be the same as yours, i.e. just below the jaws. Any farther out would possibly be a larger number thus less desired.
 

Oka

Board of Directors, Vice President
Casey
Staff member
Corporate Member
Here is how I do it.
First, You will need a mag based dial indicator.
I use a 1/4, 3/8 and 1/2 gauge pins to chuck up in the chuck to read from.

Make sure your table is dead level and is a perfect 90° to the table- Then,
Set the dial indicator up so you can test the quill shaft and take a reading. Make sure the shaft where you are reading from is clean. Clean it , then use your finger to remove any micro dirt that may be left. Take a few readings to assure it is accurate. If there is Zero runout, great! - if not record that number.

Now chuck up a pin, if you do not have one you can use a drill bit, use a new one if possible and read from thee solid shaft part. Take some readings and record them. If there is say 1.5 thousandths, then the run out would be that times 2 ... or 3 thousandths, if there was 1 thousandth runout in the quill that would indicate the runout on the chuck is 2 thousandths (3-1).

Average runout on a good quality chuck is about 3-5 thousandths. Machinist grade chucks are usually 1/2-1 thousandths.

I do the testing with at least 2 pins - a small and larger one. That way I can assure the chuck imperfections are consistent in the chuck build. Otherwise, I won't know the chuck may be good holding a 1/4 drill but a when using larger bit it could revel a bigger quality issue.
 
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Scott H

Scott
User
@Oka Thank you -- so when you are measuring the pin are you measuring as close to the chuck jaws as possible?

I realize you could potentially measure runout in a variety of ways in an actual setup, just trying to figure out how to interpret what I see in online catalogs and compare to what I have currently.

@pop-pop That is kind of where I am a little confused, because measuring close to the jaws is going to give a smaller number but doesn't really say much about how much the chuck contributes to making the bit wobble off axis.
 

bob vaughan

Bob Vaughan
Senior User
There's a 'gotcha' detail to that TIR spec. That was determined by installing the chuck on a very, very true arbor at the factory's testing laboratory. A bench top drill press from China may very likely not have the same tolerances. When I get unacceptable runout with a drill press chuck, its usually the arbor or other things. It used to be that I could put in a hardened 1/2" steel dowel and peck on it one way or the other and tap the dowel back to true. With consumer-grade drill presses from Asia these days, all bets are off. Tap too hard and the press is likely to get damaged.

Below is a USA-made Clausing that got bent out of shape. I got out my porta-power and bent it back into shape. After getting it very close, I installed a chuck with the dowel and beat in in the rest of the way until I got 1-1/2 thou. TIR. I did this several times on other presses that were drilling into castings that weren't dogged down. Those shots were taken in 2008 and as far as I know, that press is still in use today.

1       dp bent - 1.jpg 1       dp bent - 2.jpg
 

chris_goris

Chris
Senior User
When determining runout, you have to be very careful about what youre measuring. In the methods described above, the chuck jaws could theoretically be dead on zero runout and still you can get an unacceptable reading. How, you ask? the drill diameter itself , for one. We all assume that a drill bit has a true diameter and in theory, again, it doesnt. Also, runout and Total runout, or TIR are 2 completely different things. Runout is determined by just measuring one axial position (distance from the table as a point of reference, for instance ) but TIR, or Total indicator reading is determined by sweeping the indicator vertically from the table or multiple readings along the rotating axis. So, to answer your original question, I would ask whoever is supplying TIR numbers for a clear definition of how they arrive at these numbers?.
 

tvrgeek

Scott
Corporate Member
Always do a total cleaning of the chuck before measuring. Build up inside the chuck can cause large issues. Buildup in the taper can also be off as well as the taper not perfect to the bearings. Then any bearing play adds in. This means, you are always measuring a system runout, not the chuck. You can measure using a lathe dead center the drill runout independent of the chuck.

Anyway, even on a Chinesium chuck, quill play is usually far worse than runout. Darn cheap drills no longer have a split head and we can't adjust the slop. Fully extend the quill on a drill and you will have slop more like .1, not .001. ( or .2 on a HF) Enough to be a problem removing waste from mortices.
 

Scott H

Scott
User
This is a ton of info to digest but I think mainly what I am hearing is,
  1. That it's not cut and dry how to interpret this catalogue I'm looking at, and
  2. I should at least give cleaning my chuck a try
  3. Down the road I need to just get a better drill press, which I already knew.
I have cleaned mine in the past but I feel like I'm seeing more runout than I used to, and I've suspiciously been drilling metal, so maybe I got a chip stuck up in there from changing bits. I don't actually have the wedges to pop it off the spindle right now, my chuck is a JT33 that mates directly to a spindle I think instead of having a MT2 adapter or something, so I had to do it when I popped off the chuck by accident from vibration. Got some wedges in the mail so hopefully I will be able to do that on demand in the future.

Alternately something in this cheap small drill press is just wearing down.
 
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Scott H

Scott
User
So just as an update I replaced the chuck with this inexpensive one that I ordered along with my wedges, just in case.

What I found after swapping...
JT33 taper on spindle has virtually zero runout
Chuck body has maybe 0.001"
Top of a precision ground 1/4" drill rod in the chuck has maybe 0.002-0.0025" runout
Bottom of the precision ground 1/4" or 3/16" drill rod about 2.5" to 3" from the chuck jaws is something like 0.005"

Previously that last number was like 0.015".

So I'm happy. Only thing I'm noticing is the sleeve has a lot more friction than the old one did, when it is loosened it is not as easy to just spin the sleeve without accidentally spinning the whole spindle. Am I supposed to flush out shipping grease and put something else in there?

The old chuck could be fine too, could have just been some crud in there somewhere, I just didn't bother trying to clean it since the new chuck was an improvement.
 

bob vaughan

Bob Vaughan
Senior User
I'll often flush a new chuck with lacquer thinner. On keyless chucks, they have to be taken apart in a pot with a magnet in the bottom to catch the loose balls.

Below is a new old stock Supreme brand chuck. The grease has devolved into almost an adhesive. Cleaned it with lacquer thinner and an industrial toothbrush type brush. It was almost impossible to turn by hand when I got it. It presses apart differently than the standard Jacobs 633C (34-33C) chuck.
1       chuck supreme - 1.jpg

Below is the standard 633C (34-33C) that came on most USA-made drill presses from years gone by. this chuck was cleaned with lacquer thinner.
1       chuck jacobs - 1.jpg 1       chuck jacobs - 2.jpg
 
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bob vaughan

Bob Vaughan
Senior User
A few drops of my favorite mechanical oil: Mobile 1 10W-30.
A funny aside and a word of caution about using Mobile 1 on clamp screws, particularly if the threads are plated. Don't do it. I did once and when I tightened the clamp really tight, the clamp unscrewed on its own a little bit. Learned my lesson there. Had to go back and wash the oil off of all the clamp threads I'd oiled.
 

Scott H

Scott
User
The chuck has loosened up a little bit with use, it doesn't spin as freely as the old one (the old one you could just spin and it would keep spinning for a bit and then coast to a stop) but it can be opened and closed without spinning the spindle too now.

It looks more like the second set of pictures you posted, where the teeth on the sleeve are integral to the sleeve.

Do you think it's worth taking apart to clean and lubricate? Accuracy wise it's working nicely for me and I don't want to squeeze or bang on it with the wrong equipment, seeing some people say you need an arbor press or something...
 

bob vaughan

Bob Vaughan
Senior User
Getting a chuck apart and back together does require pressing. I've seen some guys rig up a couple of oak blocks and use pipe clamps. If you can live with it as is, that's probably a good safe start. Maybe a little lacquer thinner will help but even WD-40 can act as a solvent some times.
 

tvrgeek

Scott
Corporate Member
I don't disassemble my chucks when I clean. Just a pot of lacquer thinner. Work it around etc. Then a drop of 3-in-one. Amazing what can come out of one. A new chuck may have a heavy "shipping" grease in it.

I bought a chuck with an integral MT. I figure one less joint, one less place for a screw up. Tried a hand tight chuck and it was a disaster so went to a proper keyed chuck. I always snug all three holes.

I upgraded from a Sears benchtop to a '90's Delta floor stander only to find it was of no higher quality. I want a Nova, but too expensive. Palmgren looks to be the top of the conventional drills only because they state their specs and no one else does. I wish the Jet and new Delta were higher quality as I like their features. I am told I should be looking for old industrial drills as their quality is much higher.
 

Scott H

Scott
User
Thank you for your help everyone, I flushed it out with WD-40 for a while and kept opening and closing the jaws and it loosened up a lot. Found some dried oil in the travel ways for the jaws and scrubbed that out too where I could get at it. Put a tiny bit of 3-in-1 in where I could. Put it back on the DP and it read 0.004" total runout instead of 0.005" at the low end (table side) of the precision rod when chucked in the bit. So now it spins freely and the runout is slightly better I am very happy.

Really appreciate everyone's input, this is the kind of stuff that is difficult for me to find without speaking directly to the people that know!
 

tvrgeek

Scott
Corporate Member
If you used WD-40, PLEASE flush with something else. WD-40 turns to gum over time. Good solvent, good Water Displacer, but not a good long tern lubricant.
 

Scott H

Scott
User
Stuff I got on hand is mineral spirits, acetone, denatured alcohol, simple green, please recommend what I ought to soak it in. Do not have lacquer thinner or else I would have soaked it in that from the start. I can get it if it is critical.
 

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