Has anyone super tuned a drill press by truing the spindle or replacing the spindle bearings with precision bearings? If so, what kind of drill press and what modifications? My old Craftsman has about .0025″ runout at the chuck. It drives me crazy to see the work piece wobbling when I am trying to drill a hole.
Thanks
Grits
Replies
Grits, 99% of the time the runout is caused by an improperly seated chuck or arbor. Use a dial indicator on a stand to find the area in the rotation where maximum runout occurs then tap it on the side of the maximum runout with a deadblow hammer. Continue the process until you get it as close as you need it. Dead on is not difficult to achieve with this process.
You may want to reseat the arbor and the chuck first. That procedure is the same as installing it for the first time.
If the spindle is out, then you might as well invest in a new drill press rather than a new spindle. You would have to take off way to much material to get it straight which would also mean you would have to replace the bearings and likely the pulleys or have the pulleys fitted with inserts.
Just a side note: Never use your precision drill press as a drum sander unless it is equipped with side load bearings.
WhatKnot Said-
[Just a side note: Never use your precision drill press as a drum sander unless it is equipped with side load bearings.]
Good Tip.
Cheers. Walker1
Edited 10/14/2005 1:09 pm ET by Walker1
"Never use your precision drill press as a drum sander unless it is equipped with side load bearings."
Hi WhatKnot,
Funny you should mention that. I recently attended a weekend seminar conducted by Shaker expert Christian Becksvoort, during which he "turned" a shaker drawer knob by chucking a piece of cherry in his drill press and shaping it with a pattern maker's rasp.
-Jazzdogg-
"Don't ask yourself what the world needs. Ask yourself what makes you come alive, and go do that, because what the world needs is people who have come alive." Gil Bailie
jazzdogg
I have to agree with WhatKnot about using a drill press as a drum sander. Most of the drill presses we use in woodworking are light duty machines. At best, putting a side load on the bearings will shorten the bearing life and quickly reduce accuracy. On the other hand, replacing bearings is not a difficult task and it would not be very expensive to upgrade them when they start to go.
The way my luck runs, bearings start to squall when you need the machine the most and on the weekend. I am a turf farmer so I deal with bearings on a daily basis.
Grits
Edited 10/17/2005 6:59 pm by Grits
The good news is, if your drill press gets messed up, you can always send it to Matthew Schenker to get repaired.
What? Ho! Was that out loud? Ducking and running,...
I meant to say, you could trade it for his Grizzly.
"...you could trade it for his Grizzly."Not any more. I donated it yesterday evening.
Well be sure to take the tax deduction if you itemize. FMV - Fair Market Value - is what you're allowed to deduct for a Charitable Contribution. If one was to go by the content of your posts, it would sound as if the FMV wasn't very high, but to me, it sounds as if your DP wasn't used very much. I would claim the FMV as fairly close to the purchase price. Take care, Ed
Ed,
I attached a note explaining all the defects in the machine, so the buyer will not be surprised like I was. If they sell it really cheap to someone who likes to fix machines it might be a good deal.
"Never use your precision drill press as a drum sander unless it is equipped with side load bearings. "
No offense intended to anyone, but I think this is a bit of urban folklore. Maybe it was a concern in the days of Babbitt bearings, but all modern drill presses use standard ball bearings, which can handle a radial load just fine. For what it's worth, I once looked up the parts list for a popular brand of drill press, and the spindle bearing was exactly the same part that the manufacturer used on their oscillating spindle sander.
I've used my DP for occasional sanding over the last 12 years and it's not costing me any sleep. If I'm wrong, the worst-case scenario is that after another 12 years, I'll pry ten bucks out of my wallet to replace the bearings.
Cheers, Kent
Kent, you are correct that most bearings will handle it now. My point is that if someone is going to go to the trouble of getting their runout dialed in to < .001 than why ruin all that work by using the tool for something its not designed for.
Get an old second hand drill press or stick an old B&D 3/8 corded drill in a vise and use it for a spindle sander if you can't afford a real one. I do the later all the time when I'm out on a job.
Have a great day
Steve
Actually Kent, while you're right that the bearings are able to handle some side load, the taper that holds the chuck into the quill is not designed for side loads. If you look at a milling machine spindle you'll see the difference. A little light sanding probably won't hurt anything, but if you push things, you may find that your chuck will fall out of the quill.
Andrew
Andrew beat me to the punch but has nailed the problem. It is not the bearings but the taper, in paticular the one that holds the chuck to the shaft it is mounted on rather than the Morse taper that holds that shaft in the quill. A chuck that screws on to it's mounting shaft will take more side load but bottom line is drill press chuck mounting systems are not designed for side loading and using them that way will knock them out of alignment or dislodge them completely.
RichThe Professional Termite
Rich,
If what you are saying is true, why did Delta put out a book from the 1930s till the '50s showing drill presses being used to route/sand/grind/ etc, all being heavy side loads?
Those days being the ones were real machines were used by real people to do a LOT?
Many of the earlier Delta drill presses had interchangable spindles that didn't use a Jacobs taper on their working end.
John W.
In my experience, it takes significant force to dislodge a properly assembled taper. Like I said, I haven't had any problems.
Absolutely true. I cannot agree with those who say the taper is unstable under radial loading . Most engineering drills use it for good reason. I have yet to see a milling machine , other than a pissant, that does not have a taper fit chuck.
I also feel that the bearings on a typical ww drill press, as we know them now, are well able to take the radial loading imposed by drum sanding etc.even though they are 'ordinary'ball bearings. You can check this by referring to a bearing specifications book that each bearing manufacturer has-the max loads are specified.Philip Marcou
"I cannot agree with those who say the taper is unstable under radial loading." It depends on which taper you are talking about. The morse taper being quite long will hold up rather well but the taper that holds the chuck on the mandrel is only about 5/8 long and will not take much side loading.
"I have yet to see a milling machine , other than a pissant, that does not have a taper fit chuck." Milling machines have special holders for end mills and collets are normally used for other tooling. If you are using a jacobs style chuck to hold end mills then it is only a matter of time before a problem arises. Either something will happen to spin or break the endmill and mess up the chuck jaws or more likely the mill will grab and dislodge the chuck from the mandrel. When this happens it is hard to get them to line up properly again. Early in my machinist days I did not know better and being impatient chucked up a 3/8 single end mill in the good drill chuck and proceeded to mill away. Got about 3" and it came apart. Next thing that came apart was the shop foreman. After he was done reaming me he proceeded to introduce me to all sorts of wisdom of different holders for various tooling. We ended up getting a new mandrel for that chuck to get it to run true again.
"I also feel that the bearings on a typical ww drill press, as we know them now, are well able to take the radial loading imposed by drum sanding etc.even though they are 'ordinary'ball bearings." I agree. I never said the bearings wouldn't take the load, only the taper. (not the morse taper but the other one whose name I can't remember right now)
I know there are all sorts of devices on the market to use on drill presses for sanding, milling or whatever but just because something is on the market dosen't mean it's a good idea.
Bottom line, we each can use our machines in what ever manner we see fit or feel comfortable with.
RichThe Professional Termite
Bravo... point well made and absolutely correct. Darn, just when I was thinking about converting my Oscillating sander into an upside down drill press. LOL.
If you did that at least the chuck would not fall off-5/8" stubby taper and all-LOLPhilip Marcou
DANG.. You one of them B&S (Brown & Sharp) experts that came to our shop?
You are on target. At least, that is the way my Bridgeport works.
Grits
Edited 10/20/2005 3:18 am by Grits
Trial, I guess a lot depends upon the quality of these tools and machines. That little drill press you see takes that Jacobs #34 chuck on the end of a taper-the taper is actually 11/4 inch. not 5/8 inch-never had a problem-even though I have in the past abused it by doing things other than drilling with it.
I also have a Frizzly type "mill drill" and sometimes use the chuck to hold milling cutters which are too big for my Emco mill collets-never a problem there either. Maybe the "non Jacobs" chuck for that is so soft and flexible that it actually sticks to the taper-it is certainly not easy to get off.
On a different tack-could you have a look at post #26265.5 where I refer to gauge plate I am using to make a plane-am I going to have trouble peening those dovetails-do you have any advice before I go for it?
Edited 10/20/2005 4:27 am by philip
Philip
I am not a metallurgist so take this with a grain of salt. I would think the gauge plate would pein ok. Try it on a small scrap. If you can saw and machine it without undue burden then it should be soft enough to pein or possibly punch instead. I am not real familuar with what you are doing so not sure what you are trying to do. My stint as a machinist was only a few years. I have been a patternmaker most my working career.
Rich The Professional Termite
Let me ask another question. I posed the same question to a Delta rep recently. My Delta press has about the same .0025 runout. I was skeptical of his answer which, among other things already stated above, was to be sure to tighten the bit using all 3 holes on the chuck, not just one. I tried that and was able to reduce the runout to about .0015. I'm not sure why this would have any effect, but would like to hear if anyone else has heard of or experienced this.Fostering the artistic rebirth of trees.
"I am not sure why this would have an effect". It is /was standard prctice to tighten chucks from all the holes as evenly as possible, to even out the wear rate, clamp the workpiece securely and for ensuring the workpiece runs as true as possible , assuming all else is o.k.
The typical chucks supplied with "lighter duty machinery" these days are pathetic, and very susceptible to the symptoms of uneven and or overtightening.
If you have not got a good quality chuck on your machine do yourself the favour of upgrading to an industrial Jacobs or Tos if you get them there, or else you will be worrying about a lot more than .0015 .Philip Marcou
Edited 10/24/2005 5:57 am by philip
In the machine trades, this has been the standard advice for tightening a chuck for ages, but it isn't well known in the woodworking trades.
When you tighten the chuck with the key, the leverage on the gear toothed sleeve cocks the sleeve a bit so that it doesn't bear equally on all three jaws of the chuck, causing one jaw to be tighter than the other two, which pushes the bit slightly off center. By using all three key positions you even things out.
For the best alignment first gently tighten the chuck on the bit by using all three key positions, then go around a second time to fully tighten the chuck. In addition to centering the bit more accurately, using all three holes will considerably improve the grip and eliminate the slippage that commonly occurs when only one hole is used.
John W.
Edited 10/28/2005 11:07 am ET by JohnWW
Thanks for the explanation, John. That is something basic that I, and it looks like a lot of others, are not aware of. It now makes sense and will certainly be on my list of best practices.
MandyJoyFostering the artistic rebirth of trees.
Huh, I didn't know to tighten using all three holes either. Thanks for the tip.
I had heard that about newer drill presses not having side load bearings but decided to check it out tonight. I looked at an old Delta parts manual for a drill press from the 1950s and it is pretty close to the same as a current one, no additional bearings.
Drill presses are important to me as I produce a lot of work using a drill press. People used to do a lot more with drill presses than they do today. Surface grinding, shaping, dovetailing, even milling metal on them. Spindles had threads so some of the accessories could be screwed onto the quill.
That said, anyone trying to get less than a couple of thousands of runout is chasing their tail unless they opt for a high grade US made chuck on a higher end machine. You aren't going to get it with a low end Chinese drill and chuck, thats for sure!
Geee .0025" runout
Is that Bad?
That is about two thicknesses of cigarette paper!
EDIT:: Just funnin' ya,,
If the run-out is small maybe it is not the bearings.. They have to be REALLY abused to get that bad..
I work in metal so I do strange things.. But here goes anyway..
If I 'think' all is normal.. I will drill/tap into the casting.. Put some brass dog head setscrews/locking nut in the casting that 'guides' the quill in the right direction..
Works fer me!
Edited 10/14/2005 2:52 pm by WillGeorge
WillGeorge
If you work in metal, .0025 is a bunch. I also do machine work and I have a tendency to compare my woodworking tools to my metal working equipment. I have found it is a good way to drive yourself crazy.
The runout goes all the way to the spindle. I like your idea. First I will take it apart and check the spindle between centers. It probably won't be hard to fix. I don't expect it be a good as my Bridgeport but less than .001".
Thanks
Grits
Can anyone direct me to a procedure for disassembly and bearing replacement in a typical drill press?
Thanks.
Corners
Sorry it had taken so much time to reply to your question but I have bee a tad busy.
This explanation is going to be general, so do not hesitate to email me with more specific questions.
First it to remove chuck firm the spindle. Then remove the quill from the head. This will give you to get everything clean. In the process you will have to remove the pulleys and everything else holding the quill in the head. Both top and bottom bearings should be held in place with retainer rings. Remove them. Clean exposed portion of the spindle shinny. The direction the spindle is removed from the quill may vary from machine to machine. On mine, I will press or tap the top of the spindle. This will remove the top bearing from the spindle and the bottom bearing from the quill. Turn the spindle over and press the bottom bearing off the spindle.
Get the spindle clean and deburred. Be careful not to remove much metal. just slick it up so you new bearings will slide in smoothly without damaging them.
Reverse the process for assembly. I would use a little anti-seize compound during the process.
I hope I did not leave anything important out. If I did, someone please correct me.
Good Luck
Grits
Lee Valley sells a Drum Sanding Kit with a bottom bearing for your drill press. I guess that would alleviate any concerns with regard to side load causing runout, or alignment issues.
Cheers. Walker1
I used to rebuild metalworking machinery for a living and have had some experience with spindles and bearing replacement. The typical home shop drill press is not a precision instument and yet if you checked the runout of a class 3 bearing typically found in this type of machine you would find that it would run out only a few tenths. Matched precision bearings or "accidental bearings" so called because they are set aside when found in the production run because they just happened to be close tolerance. These bearings are very expensive (class 5 or higher) and would be overkill.
Get a dowel pin, chuck it up and check the runout. Another thing to check is the inside of the taper. Remove the chuck and make sure its clean inside. If the bearings are causing your runout chances are the whole spindle is loose and the bearings might be noisy. How about your drill? is it good quality or bugged up where gripped by the chuck jaws? Your typical drill is not high quality and even if brand new could have runout.
You don't say what your end result is when drilling a hole, Is it oversize? What are you trying to do that you need such precision in a drill press?
TJB
I also have a little experience with machine tools. Not rebuilding for a living but for my own use and fun. My first mill was a small Enco. I upgraded the spindle bearings in that machine and greatly improved the performance. That was many years ago. The bearings were not cheap but it turned into a fairly accurate, usable, light duty machine. I also had an Enco lathe. My experience with ChiCom machine tools is you first take them apart. Your then clean all the metal shavings from inside the castings, deburr the gears, tighten everything up, etc.
My last two projects were taking a Series I BP down to bare metal, had the table reground, cleaned, painted, and/or replaced everything that needed replacing. I am almost finished with my SB 10L toolroom lathe.
Back to the drill press. The runout goes all the way to the spindle. I think the problem is in the bearings or the spindle itself. I just read a comparison on drill presses adequate for woodworking. All of them had, in my opinion, excessive runout. Some, in my opinion, were usable but many in the test would not be. In my opinion.
My first step will be to take the head apart and locate the problem. I have a hunch, I will end up replacing the bearings and either turning the existing spindle or making another one.
If I have to do anything precise, I can always use my BP or lathe; however, I would just like to see the machine run true. To see my workpiece wobbling when I am drilling a hole is just irritating to me. Whatever, I will make a fun project out of it.
I thought about replacing the press. but the ones I was looking at, mentioned in the test above, did not preform any better than the one I have.
What level bearing would you use to get the runout less than 0.001", assuming the spindle is straight and true.
Thanks for your input.
Grits
I use a drill press extensively as a wood milling machine using everything from standard drills to endmills and forstner bits.
If your workpiece is "wobbling" it isn't because of .002 runout on the spindle!
Is your table ridgid enough, same goes for your part holddowns? Is the cutting tool sharp and ground correctly? What sort of wood are you cutting? Is your feed rate correct?
Well .001 is not really a tough tolerance as far as metalworking goes. A decent class three bearing from a reputable company will have much less than .001 run out. <!----><!----><!---->
As you have mentioned yourself what can give you a problem is the stacking tolerances from the spindle and how tight and concentric the bearing housings are and how much the spindle runs out all by itself.<!----><!---->
If there is no play in the spindle, side to side and the bearings are quiet chances are it’s not the bearings that are giving you the problem. The ideal thing would be to grind the spindle while it’s in the drill press but that usually is not practical. I have never tried to tune up a drill press my drills don’t wobble and it’s an inexpensive (read cheap!) Jet Drill press that I paid around $300 for. The thing I did do was install a keyless high precision chuck. I was lucky and found one for free but I bet they would cost around 3-500 bucks! I tossed the chuck that came with the machine in the trash.<!----><!---->
Good luck with your tune up!
TJB,
Thanks for the dose of reality! Don't laugh but I have a question for you. Isn't runnout normally checked by hand without the motor running? Is there a way to check it under power without damaging the tip of the indicator?
Thanks in advance!
Michael
Michael:
No such thing as a dumb question. Sure you can put an indicator on the spindle while its running. I would slow it down as much as you can and make sure nothing is going to wack the tip off. I would not do it for long, just enough to check for runout.
TJB
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