How do you measure runout on drill press?

I have a quill play in my Frox Shop 17" drill press.
When rotating with no load the runout is just 0.002" but if you move chuck with
hands back and forth test indicator shows 0.030 runout. Woodstock Int.
(manufacturer of
all Fox Shop tools) warranty guy is saying that I am not suppose to try to move
while measuring runout. "The right way" to measure runout is to do it while
drill runs
on lowest speed with no load.
Quill set screw is already tighten to the point when I can hardly move spindle
BTW I just tied to drill 3/8 hole in 1/4 thick mild steel and can see that when
bit is half way through "hole" is somewhat triangular. After the hole is through
looks pretty round with rough walls. Is it suppose to be like that or it's
because of
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BTW The steel piece I was drilling was firmly clamped at both ends to the table. Drill bit was a jobber length.
Alex wrote:
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To me "runout" implies a cyclical error, which typically would be measured with no loading force. Though I'd do it with the machine off.
Play, or spindle deflection under load is not perhaps something you want to suffer, but I would think of it as a different measurement.
Compared to a milling machine, a drill press is not massive, rigid, or equipped to take side loads - and the same issues (except for mass) apply to a drill chuck as compared to a collet mounted or taper shank drill. Of course a lot of cheap drill presses and chucks may be worse than a more carefully made machine of the same basic design.
If you want to drill holes easily, use a drillpress. If you want to make nice holes, use a milling machine with a center drill in a collet, an undersized drill (or sequence of them), and then a reamer in a collet.
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He's right you shouldn't rock it to measure runout, and .002 for a drill press is not bad. But .030 free play, or slop as we call it, sucks and is not acceptable in my opinion. When you measure runout you are really checking how concentric the chuck and/or chuck mount diameters are to the spindle diameters that the bearing inner races are pushed onto. It's possible you have bad bearings or the bearing could have a sloppy fit between the bearing inner races and the spindle, or between the bearing outer races and the quill. More likely it is caused by a sloppy fit between the quill and the head casting. When you move it try to see its sloppy between the spindle and quill or between the quill and head casting. Sometimes just snugging up the quill lock a little where it can still slide freely is enough. Other times some people over extend the quill with the travel limit nuts adjusted that way. In this case it is always more rigid and less sloppy to move spindle all the way up and raise the table to move the part closer to the drill.
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They are correct. You aren't returning the machine because of runout, you are returning the machine for excessive slop in the quill. Get your money back, and next time read
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before buying one, and don't buy an import DP without inspecting it in person.
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Grant Erwin
you wrote an excellent article. As for import DP it looks to me that you won't get anything with 0.001 runout for less than $400-500 and even that number is very optimistic.
Grant Erw>
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You don't need anything like .001" runout on a drill press. Stop thinking of a drill press as a precision tool - it ISN'T. Yet my old Jet 17MF had < .001" runout on it's internal spindle taper, and with a good quality Jacobs chuck it was about as good as a cheap DP gets. I've also seen other imports that had little runout. It's important to realize that before I found my Jet I looked at about 15 used drill presses, bringing my dial test indicator and mag base. Most of the sellers didn't even know that their chuck popped out of the spindle.
If you are stuck on accuracy go find $1000 and buy a good used mill drill (less if you get real lucky). Or go all the way to a knee mill.
Alex wrote:
Reply to
Grant Erwin
According to Alex :
What you are measuring is quill slop, not runout. The runout is your no-load measurement. But -- that amount of slop in the quill is fairly common on import drill presses -- unless you are *very* lucky.
That only controls slop in one direction -- you need another setscrew to control it at right angles to the current support. And I'm not sure whether tightening a setscrew against the side (or front) of the quill, without something to spread the load, is that good an idea anyway.
Note that old drill presses often were split with a clamping screw to close the split. This was normally used to hold the quill extended while you did something -- but could also be used to take up the slop in the quill to headstock interface.
That slop allows the drill to play like the ones which drill square holes, except that the square holes ones have three flutes, and a two-flute one would drill a triangular hole.
The work-around for that is to use a 3/8" center drill to start the hole. It will start better in the center punch hole, and if you take it down to the point where it is at the full 3/8" diameter, and perhaps 1/8" deep at the full diameter, that will guide the drill bit so it will do a better job.
Good Luck, DoN.
Reply to
DoN. Nichols
Thanx, Grant for posting the URL to your excellent article on drill presses! This time I book-marked it. Your articles on 4 x 6 saws and drill presses are the best I've ever seen on the subjects. The information contained in them is in the "must know" catagory for anyone seeking to tool up a basic shop.
Bob Swinney
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Robert Swinney
The voice of reason, finally!
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jim rozen

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