Drill Press Runout and Quill Slop

I have a 70's craftsman 17" drill press in my home shop, which I purchased on CL. I was finding quite a bit of runout, around 0.012". After the chuck separated from the arbor and was re-assembled, it seems to have around 0.0035" runout or so, measured with a router bit in the chuck. At one point, I was getting some oblong holes, and want to make sure before I sell another (new, porter cable) drill press, that I'm not overlooking what may be an issue.

The quill, fully extended 3.25", has about 0.001-0.002" of play front to back, and about 0.006-0.007" of play left-right.

Is this an acceptable amount of play for a home shop? Is there anything else I should be on the lookout for... just making I'm not somehow masking that 0.012" of run out I measured initially.

Machinery Discussion Guidelines since this threads gonna get locked.

rossn said:

I have a 70's craftsman 17" drill press in my home shop, which I purchased on CL. I was finding quite a bit of runout, around 0.012". After the chuck separated from the arbor and was re-assembled, it seems to have around 0.0035" runout or so, measured with a router bit in the chuck. At one point, I was getting some oblong holes, and want to make sure before I sell another (new, porter cable) drill press, that I'm not overlooking what may be an issue.

The quill, fully extended 3.25", has about 0.001-0.002" of play front to back, and about 0.006-0.007" of play left-right.

Is this an acceptable amount of play for a home shop? Is there anything else I should be on the lookout for... just making I'm not somehow masking that 0.012" of run out I measured initially.

Click to expand...

Tighten up the adjustment to squeeze down on the quill more....

extend the quill all the way down and lock in place. turn it so the quill indiactor shows the maximum large diameter runout is facing the front. use a bar clamp or pipe clamp to pull the quill back to the column and about 0.003 more to zllow for springback. release and spin it a few times and repeat. Should get it to 0.002 in 10 minutes or less.
like others said tighten the quill tightening nut or bolt first. Likely a single or threes screws on the front of the machine.
Bil lD

rossn said:

I have a 70's craftsman 17" drill press in my home shop, which I purchased on CL. I was finding quite a bit of runout, around 0.012". After the chuck separated from the arbor and was re-assembled, it seems to have around 0.0035" runout or so, measured with a router bit in the chuck. At one point, I was getting some oblong holes, and want to make sure before I sell another (new, porter cable) drill press, that I'm not overlooking what may be an issue.

The quill, fully extended 3.25", has about 0.001-0.002" of play front to back, and about 0.006-0.007" of play left-right.

Is this an acceptable amount of play for a home shop? Is there anything else I should be on the lookout for... just making I'm not somehow masking that 0.012" of run out I measured initially.

Click to expand...

Neandertal is right, PM dasn't "do' a lot of hobby-grade goods.

"meanwhile" Bill D. gave you about "all there is".

Or at least all you are going to be able to make use of, cheaply, for what was born with the original sin of being nowt but a cheap DP. Lipstick on a pig just don't last. They just lick it off and go right back to bein' pigs.

OTOH? DP slop don't matter as much has all that. Decent drills follow their own line as they "generate" a hole anyway.

- Well-balanced grind will give you good holes off a BAD DP.

- S**t-lousy grind and you get BAD holes off a GOOD DP.

So don't over-think the DP.

Just avoid crappy drills!

Sorry folks, I did look to see if there was some guidance on if this type of topic was appropriate upon registration and didn't notice the sticky. Many thanks for the thoughts. I did some testing last night, and was seeing the drill bit migrate, but less with a pilot hole bit so I think the point on the bad drills may be it. Excellent tip on the straightening of the quill. Thanks again.

Did you measure the run out on just the arbor? In your first post it sounds like you found the run out decreased from .012 to .0035 just by remounting the chuck.

You could try this. Measure and mark the maximum run out on the arbor. If you have little runout, you need to work on the chuck. If the runout is in the .0035 to .012 range try this. Put 6 marks on the chuck 60 degrees apart, and mound the chuck with each mark indexed to the arbor mark and measure the runout at each mark. With luck you will find a position that the runout of the chuck and arbor cancel.

If the runout is in the chuck you could replaced it. Another option is this- if it is a keyed chuck. Have someone with a lathe make you a 3/8 in diameter brass rod that is true in its diameter and about 2 inches long. Get some silicon carbide powder and impress it it into the surface. Take a piece of hardwood and clamp it to the table, then drill a 3/8 in hole- or one 23/64, and press in the rod. Open the chuck and put it over the rod and close it so it just touches the rod, turn on the drill, and use the handle to run the chuck jaws up and down the rod.. You can lap the jaws to run true- at least for that diameter. If it is keyless chuck it may grab the rod if running clockwise. You can run the drill counter-clockwise, but the chuck will want to open. I have not tried it- but it may be possible to use rubber bands between the chuck and the arbor to keep some tension so it will lap.

Is any of the above actually needed? That is up to you to decide.

I found in my dp if big 1/2+ drills caught and snagged in a hole in iron the quill could be moved off 0.002-5 just from the one mishap. That is why I suggested get it with 0.002 or so and that is good enough.
Bil lD

I don't know about a high quality drill press, whatever that is, because I have never had or used one. For the ones that I have used, which have ranged from $50 to $800 or so, 0.005" runout is not unusual. The 0.012" that you had does seem to be a bit much but there can be many reasons for it: the DP's spindle itself, the bearings, the chuck, the chuck arbor, and perhaps more.

First you can remove the chuck and it's MT arbor and check inside the spindle's bore with a dial indicator. First turn it by hand, preferably by turning the motor pulley (in other words, as far from the spindle as possible) and see what the DI shows.

Then put just the MT adapter back in the spindle and check it the same way as above. It should show the same runout as above. If not, the adapter may be bent.

Then with the spindle not rotating check with the DI on the front AND on one side of the MT adapter while pushing it front to back and side to side, This will test the bearings.

When all the above has been checked and all problems those steps have shown are corrected, then put the chuck back on the MT adapter and chuck up a known good round like a length of shafting. Drill rod is not necessarily straight. Check near the chuck and about 3-4 inches out from it,
This will tell you how good the chuck is,

Many $300 and $500 DPs will be equipped with a $15 chuck. But the price of a chuck is not necessarily an indication of quality, My 20" DP came with an unmarked chuck which was too big for most of the work that I do with it so I purchased a medium quality, smaller, German made chuck. Guess what? The no name chuck actually has better runout than the name brand, German made one,. It is about twice as good. Luck of the draw? Probably. Will it last? Who knows, I mostly use the German made one.

Here is another tid-bit. As was said before, the quality of the drills is probably more important than that of the drill press when drilling holes. A good quality, properly sharpened bit will drill a round hole that is close to the marked/measured size of the bit. A poorly sharpened bit will drill an oversized hole which can also be out of round. Get and use good quality drill bits.

Also, when I want the best accuracy in the location of holes that I drill, either in the drill press, in my mill, or even in my lathe first I start with a small spotting bit and make just a small dimple in the work, smaller than about twice the diameter of the next bit. Then I switch to a bit that is about the diameter of the web thickness of my final drill and make a pilot hole with it that is at least as deep as the diameter of my final bit, usually deeper. Only after all that has been done do I mount and use the final sized bit.

When drilling in the mill or lathe I do not punch the location of the hole, but if I am using the DP, I do use a punch and a 10X magnifier to locate the punch in the first place and then to judge which direction I need to slant the punch on the second and third hammer blows to correct the location of the original dimple.

I have had good luck doing it this way - with good quality, properly sharpened bits of course.

why worry about quill play on a dp?

Remove the chuck from the arbor and indicate the arbor tapered bore directly. If as I suspect the arbor is within .001" then the chuck is your problem. Replace the chuck with an old Jacobs (new ones from China) or Albrecht or Rohm and you will be happy.

metalmagpie

Sometimes Jacobs tapers don't seat with good alignment. They are very short in relation to the drill length, so it doesn't take much misalignment to make the drill run out. I have personally seated, checked, removed and reseated, checked, removed, etc. a chuck and found different runout every time when just using the "slam seat" method. I get better results by heating the chuck to a couple hundred degrees and popping it on the arbor gently.

They can usually be tweaked a little bit like described by Bill D above also. I tend to do mine a little differently so as not to stress the spindle bearings. I mount the chuck then chuck up a nice straight piece of dowel pin and set the chuck and arbor between centers. Measure TIR and mark the high side. Set in aluminum v-blocks with high side up and give it a gentle nudge in the small arbor press or some taps with a dead-blow hammer and check again. One or two adjustments and that chuck will run damn near dead true.