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Re: Drill Press Runout

If the quill is not perpendicular to the table the bit will walk before it starts drilling and it would generally be in the same direction all the time. Also if the set up is not rigid when you put pressure on the bit it is going to deflect and drill "off center" from the relaxed position. Even with a small amount of run out i doubt you would get oblong holes, are the bits well sharpened?

Re: Drill Press Runout

I didn't check the perpindicularity of the quill table - are you thinking that might cause the bit to drift towards the user?

Material was clamped on 2 sides to the table with dewalt HD squeeze clamps, with a 2x6 material underneath.

Re: Drill Press Runout

Did you check to see if the quill is perpendicular to the table? How are you holding the material while drilling?

Re: Drill Press Runout

Thanks for the thoughts about practical use of the drill press. I'm not expecting anything amazing from it, and I am trying to understand practically what I can expect, since I have not owned a drill press previously and have only used one many years ago.

Last night I did a lot more investigation into this and tested a number of holes. It reminded me of some of the challenges I have seen. It is clear that I definitely need to buy a good set of drill bits (separate topic), and now need to determine if the bits or technique are the root of the issue or the user. I probably just need to order a new set of bits to find out, and am curious if these behaviors sound like bad bits or a drill press issue:

What I observed was:

Drilling some sheet metal (I'm going to guess 12 gauge) with:

1/4" older Milwaukee standard twist bit, in an appropriate RPM range. Unless stated otherwise, feed rate was definitely not too fast (if anything, too slow... chips too small)
- Feeding relatively fast, hole came out very ugly. Almost triangular with rounded tips and with a burr around the top edge; maybe a bit oblong.
- Feeding slow, hole came out similar to above, but to a lesser degree. Still pretty ugly.
- With pilot hole, hole came out much more round, but not perfect. Slight burr on the top edge
The key thing I noticed with this bit for with and without a pilot hole, but much more on the one without is that the bit as being pushed towards the operator at the tip. Once the hole was complete, lowering the quill again the bit could not go straight into the hole, rather the bit tip had to migrate towards the user. Maybe 1/16" on the no-pilot hole scenario, and 1/32" on the pilot hole scenario (rough guess).


17/64" Dewalt pilot point bit that has seen some use
- With no pilot hole, came out at least as good as the Milwaukee with a pilot hole, but still a bit of a top side burr ridge, but pretty acceptable for every day general use
- With pilot hole, came out a bit cleaner
Tip migrated, but I had to look pretty close to see it... probably 1/64"

1/2" Milwaukee standard Twist bit (has not seen much use) in appropriate speed range:
- With no pilot hole it came out very ugly, similar to the 1/4" Milwaukee bit.
- With pilot hole, came out looking pretty good for every day general use.

With the crummy holes, and the very visible bit tip migration on the 1/4" bit, is this all related to a crappy bit, or is it likely any of this is due either the front to back quill slop I previously mentioned, or some other issue with the drill press?

At what size hole in mild steel should a pilot hole be required (seems like a lot of extra steps for a 1/4" hole), when using a properly operating drill press of this grade with a good quality and shape bit?

Thanks!

Re: Drill Press Runout

Originally Posted by machinisttx

To clarify, if the point is .003" off center, the hole will be at least .006" larger than it should be. That is leaving aside other considerations such as heat or unequal cutting edge angles.

I think that may explain a lot of runout problems....

Re: Drill Press Runout

Originally Posted by rossn

No one has any thoughts as to the drill press quill slop, and what is within reason for a drill press in good shape?

" with it fully lowered (3.25" travel). Front to back, I get 0.001-0.002", side to side, I get more slop at 0.006-0.007" "

My day job title is machinist and has been for almost 20 years. Consumer grade drill presses are not precision machines. If you need better precision, you'll have to buy a mill, or at minimum, a true heavy duty radial arm drill press like one of these. https://www.radialarmdrillpress.com/...dial_drill.php If you need to put a radial load on it, you need to buy a mill. Drill presses are made for axial loading only. If holes are coming out oversize, the most likely culprit is an incorrectly ground drill point. If the point is not exactly on center, the hole will be enlarged by at least twice the amount of error..... To clarify, if the point is .003" off center, the hole will be at least .006" larger than it should be. That is leaving aside other considerations such as heat or unequal cutting edge angles.

Re: Drill Press Runout

No one has any thoughts as to the drill press quill slop, and what is within reason for a drill press in good shape?

" with it fully lowered (3.25" travel). Front to back, I get 0.001-0.002", side to side, I get more slop at 0.006-0.007" "

Re: Drill Press Runout

To remove the chuck from the arbor you'll need a pair of tapered wedges like these or homemade variety.
Attachment 1715180

http://www.jacobschuck.com/accessories/wedge-set

Read this article as well

http://www.jacobschuck.com/drill-chuck-removal-guide

Re: Drill Press Runout

General wood and metal use. It's hard to say why I was getting oblong holes when I drilled some 1/8" steel previously... it was a quick and dirty job for drilling some mounting holes, and I did clamp the work, but hard to know what was going on. I was more worried about getting the radiators mounted at that time than making it pretty.

Re: Drill Press Runout

What are you going to be doing with it? Initially you mention an oblong holes, is your table straight and fixed flat? My jet table will move if into pinned in place.

Re: Drill Press Runout

Hi, thanks for the information and feedback.

To clarify what I'm really after: I need to determine if this older (heavier built) drill press is OK, and if I can clear out the other drill press, which is still boxed up. Or if I practically do have an issue and should sell the older one. One needs to go, as I need garage space for remodel materials.

I am confused because at one point it had 0.012" runout, but now much less (0.0035" with the original chuck). Is it possible that I am now measuring less runout, but that there is still an issue (such as the chuck possibly being very centered now, but not all the time)? I just want to be sure before I sell the boxed one that I don't have a bigger issue.

I am inclined to think that if the spindle only has 0.001" runout, that the worst case is I may need a new chuck and arbor. Perhaps it is the stack-up of the tolerances between the chuck and arbor now offsetting each other (or better aligned).

This may be a silly question: What is the safe and easy way to separate the chuck and arbor, such that I can try different alignments and measure runout?

Now, I just measured the front to back and side to side slop in the drill press quill, with it fully lowered (3.25" travel). Front to back, I get 0.001-0.002", side to side, I get more slop at 0.006-0.007". Is this my issue?\

Shortfuse: I use a cheap dial indicator and magnetic base from Harbor Freight.
https://www.harborfreight.com/1-in-t...tor-63521.html
https://www.harborfreight.com/multi-...ent-63663.html

Re: Drill Press Runout

I have a Ridgid 15" DP, Model DP15501 that I bought new from Home Depot about 9 years ago. It has been great to use, a workhorse, for general shop work drilling mostly steel. Lately, I think I've been getting some runout on 1/4" to 1/2" holes. I'm using a high quality drill bit set from either MSC or McMaster-Carr, don't remember which place, so I'm pretty sure it's not the bits.

How does one go about measuring the runout and is there a tool or rig to do that?

Re: Drill Press Runout

Sounds like the original chuck/arbor was not installed correctly/clean. Nothing wrong with .003" runout in a drill press.

Re: Drill Press Runout

Originally Posted by rossn

I bought a used Craftsman 17" Drill press, from around 1979. 200-3600 RPM, 3 pulleys. I had used it a few times, and found some 1/4" holes to turn out a bit oblong... measured runout at around 0.012+", some time back.

Thinking I made a bad buy on the craigslist DP, I ran across a lowes tool blow-out sale, and picked up a Porter Cable PCB660DP 15" drill press for around $160, which historically was reported as a good value.

Before I setup the new drill press, I put the New PC chuck and arbor in the Craftsman and measured the runout at about 0.0035". In the process of swapping the chuck the original arbor separated from the original chuck, and I re-assembled them. I now get about 0.0035" on the original chuck with a router bit installed, and if I measure at the spindle, it is closer to 0.001". Measurements remain about the same at the top and bottom of the quill travel.... maybe a little tighter at the bottom of the travel, which seems counter-intuitive.

Now that I've seen the drill press components side by side, I'd definitely rather keep the Craftsman if I think it is possible to manage the runout to 3.5 mils.

Do you think it is likely that the issue has to do the alignment of the chuck and arbor, or, do you think it more likely that the chuck itself has some issues?

runout on a drill press is rarely any problem at least on the 100,000's of holes i have drilled
.
you can try disassemble chuck arbor and turn one a bit and reassemble. that is each piece has runout and when put together runout can add or cancel each other out.
.
chuck jaws get dirty in chuck i usually spray non residue electrical contact cleaner til its dripping and work the jaws opening and closing chuck flushing dirt out.
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runout doesnt give oblong holes it will give excess oversize holes especially at beginning of hole in a bellmouth shape. if drill sharpened unevenly it will also
give oversize holes too.
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most use a smaller pilot hole or use a spot drill for location that the other drills will follow. in a machine shop where drill tool holder runout is measured
cause of many reasons like drill bit not always straight runout of 1000's of drill tool holders can easily be in the .010 to .100" range. longer tools have
greater runout potenial. usually if you measure runout on dozens (or hundreds) of drill presses most will have significant runout. that is normal or average

Re: Drill Press Runout

Not sure I understand. If you can use the Porter Cable arbor and chuck in the Craftsman and get 3.5 thou, you're doing great. Most chucks in all of the presses are absolute garbage. A Jacobs Super Chuck is rated at .003 so your doing fine with the chuck you have. You also grab the quill and see if there is movement side to side. Bad bearings can also be an issue. I rebuilt my press with all new bearings and a new Japanese chuck. It's an older 20" Craftsman I purchased new about 30 years ago. It's nice and tight all around indicating at 1.5 thou.

Drill Press Runout

I bought a used Craftsman 17" Drill press, from around 1979. 200-3600 RPM, 3 pulleys. I had used it a few times, and found some 1/4" holes to turn out a bit oblong... measured runout at around 0.012+", some time back.

Thinking I made a bad buy on the craigslist DP, I ran across a lowes tool blow-out sale, and picked up a Porter Cable PCB660DP 15" drill press for around $160, which historically was reported as a good value.

Before I setup the new drill press, I put the New PC chuck and arbor in the Craftsman and measured the runout at about 0.0035". In the process of swapping the chuck the original arbor separated from the original chuck, and I re-assembled them. I now get about 0.0035" on the original chuck with a router bit installed, and if I measure at the spindle, it is closer to 0.001". Measurements remain about the same at the top and bottom of the quill travel.... maybe a little tighter at the bottom of the travel, which seems counter-intuitive.

Now that I've seen the drill press components side by side, I'd definitely rather keep the Craftsman if I think it is possible to manage the runout to 3.5 mils.

Do you think it is likely that the issue has to do the alignment of the chuck and arbor, or, do you think it more likely that the chuck itself has some issues?