drill press spindle runout question

[marcofsiny]

I hope someone can help...I have an old W/T drill press and noticed runout. So far I eliminated the chuck and now I'm down to checking the spindle taper with a dial indicator. I apun the spindle by hand with the belt off. I am horrible at math so I dont know what I'm looking at. The DI measures in .0001 and I lowered the quill so it reads at different points, and I get the same results.
here is a video to show what I'm looking at
video
the main question is,,how do I go about fixing this???

[PeteM]

You've got a little over .002 TIR, which would be a problem in a mill but isn't that bad in an old drill press. Could be a slightly bend spindle, the bearing housing cocked in the head casting, a gummed up arbor, badly worn bearings, etc. If the bearings aren't noisy and there is no noticeable movement between the spindle and bearing housing, I wouldn't worry about it.

[mechanicalmagic]

the main question is,,how do I go about fixing this???

I wouldn't even think about trying to "fix" a .002" TIR runout on a drill press.
I would celebrate if mine was that good.

DAve J.

[J Tiers]

the main question is,,how do I go about fixing this???

I wouldn't even think about trying to "fix" a .002" TIR runout on a drill press.
I would celebrate if mine was that good.

There is a lot of truth in that,......

Of course, if the DP spindle is bent, and the tip of the drill wobbles in proportion to how long it is, that could be VERY annoying........

[randyc]

If the runout on any of my drill presses was less than .002, I'd be impressed, as Pete and Dave noted. J Tiers makes the point (as I interpret it) that a more practical method might be to measure the runout at some distance from the chuck, perhaps by indicating a length of drill rod a couple of inches long.

There's no "standard" except what you find acceptable for your work. As a practical tolerance, I'd be satisfied if the runout at two inches didn't exceed the diameter of a center-punched-mark, maybe .030 to .040 ... If the runout exceeded that amount, I'd try two or three different chucks (rotating them in different positions in the spindle) to find the best one - imported chucks are inexpensive.

One can always find a use for extra drill chucks - I have a few that are mounted to knurled handles, useful for gripping drills, small reamers, countersinks, needle files, and so forth. Pin vises are handy for some chores but I like a substantial "feel" for a few hand operations.

Might be worth noting that even large amounts of spindle runout can be accomodated if the workpiece can first be centerdrilled with reasonable accuracy, LOL. In my youth, there were standard techniques for "drifting" a recalcitrant starting hole back to its desired location with a cape chisel and a small hammer. I don't think that such techniques are taught anymore.

Cheers,
Randy C

[Inspector]

Is there any movement of the indicator when you apply side to side pressure to the spindle when it is retracted and again when it is extended? Is that where you are getting the runout that is concerning you?

Pete

[EdK]

Randy,

Nice idea for using spare chucks to hold taps for hand tapping. I have the chuck that came with my mill that just didn't do its job very well so I replaced it with a nice Llambrich ball bearing chuck. Now I have a use for that useless chuck.

Thanks,
Ed

[marcofsiny]

Thanks everyone. All that needle travel on the dial looks real wrong to me.
What i didnt mention is that with a drill bit in the chuck the end does wobble enough to see it or make an oval. My 12" craftsman DP just about makes the DI needle move at all (I was surprised).
Am I using the right DI to measure with?? Do I need one that is .01 or .001 (???)
Inspector: I will try to push sideways on the taper with the DI touching it,,,I dont think there was play.
I can send this quill assembly out for a cleaning and new bearings ,I just didnt want to spend the money and it come back the same.
Randy C: I'm interested in that technique with the cape chisel (also never heard of one)

[KRONIIK]

...SNIP...
Randy C: I'm interested in that technique with the cape chisel (also never heard of one)

I learned that one in high school, Industrial Arts 1979!

Just use a cape chisel to gouge out a groove in the hole (much like a keyway) in the side of the hole in the direction you wish the drill to move. Path of least resistance-the drill will push itself away from the opposite side; toward the groove.

BTW, I don't think I've even seen a cape chisel in thirty years! I wonder who still makes them.

[randyc]

... BTW, I don't think I've even seen a cape chisel in thirty years! I wonder who still makes them.

I suppose that the usual manufacturer would be those - like you and me - with a torch, some drill rod and a can of used motor oil, LOL ! I DO have a couple of "Craftsman" originals from the late sixties, though. (Great explanation of the "drifting" technique, BTW.)

Cheers,
Randy C

P.S. Kroniik, I have a couple of decades on you - interesting that the technique was still taught in your day !

[PeteM]

The .0001 per graduation indicator you already own is fine for what you're doing. 0005 or .001 would be OK too.

If you can see a drill wobble once it's back on the drill press, you likely have a problem (and perhaps not just the .002 TIR measured at the taper). Could be how the chuck is seated on the taper, the chuck jaws, a bent drill, etc.

What you want to do is put a precision pin (steel dowel pin OK) in the chuck and measure about 2" or so out from the chuck body. Let us know what you find.

[marcofsiny]

What you want to do is put a precision pin (steel dowel pin OK) in the chuck and measure about 2" or so out from the chuck body. Let us know what you find.

What I did was use a piece of 3/8ths drill rod and measured about 2" down from the chuck. That same dial ind. in the video turned 2 complete revolutions and stopped at about 3.5
That same drill rod on a different drill press is fine.