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Thread: Drill Press/Forsner bit runout question

  1. #1
    Join Date
    Jan 2018
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    Vancouver Canada
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    Drill Press/Forsner bit runout question

    I have a benchtop drill press, and I've noticed that my forsner bits seem to wobble as they're rotating. Worse, I had to make a few holes and plugs on an ongoing project, and the plus are not tight in the hole.
    Today I got my dial indicator set up and checked the runout.
    With the chuck empty, the runout was negligible about .002" -.003".
    With a 1/4" Lee Valley bit, on the shaft just below the chuck, the runout was .012". At the bit, it was .012-.014"
    The plug cutter is also Veritas.
    The press is a Ryobi D121 with (I assume) the original chuck.
    I really cannot afford a Rikon at this time.
    What do you all think; change the chuck, replace the bits, what? I did not try any of the Freud bits I have,
    Young enough to remember doing it;
    Old enough to wish I could do it again.

  2. #2
    Join Date
    Mar 2006
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    SoCal
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    20,275
    I would first just re-chuck the bits a few times and re-check. Similar to an inexpensive tablesaw fence that has to be checked and rechecked every time you move it, a low end DP and/or chuck may need a few tries to perform its best. Second thing to try is to remove the chuck, clean the taper and the chuck and put it back on. This has solved an issue for me at least once in the past. Obviously the longer or larger the bit, the greater the effect of the run-out.
    Last edited by glenn bradley; 05-28-2020 at 9:22 PM. Reason: hyphenation
    "The Danish government believes that if we train 5,000 designers, and produce
    one Hans Wegner, the money is very well spent." - Ole Gjerlov-Knudsen

  3. #3
    Join Date
    Mar 2003
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    SE PA - Central Bucks County
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    52,952
    Did you try reseating the chuck if it's removable and uses a taper? That often fixes or reduces runout on a DP.
    --

    The most expensive tool is the one you buy "cheaply" and often...

  4. #4
    Join Date
    Sep 2016
    Location
    Modesto, CA, USA
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    4,308
    How are you measuring runout on a empty chuck? those numbers mean the quill and bearings are good.
    Buy a tapered plug cutter.
    Bill D

  5. #5
    Join Date
    Jan 2018
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    Vancouver Canada
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    Thanks Bill. My plug cutter is a tapered Veritas.
    Young enough to remember doing it;
    Old enough to wish I could do it again.

  6. #6
    Join Date
    Dec 2006
    Location
    Corcoran, MN
    Posts
    199
    It is more likely the fit of the taper, judging from members' comments over the years. I knock out the taper using the drift that comes with the press. I reseat it with the chuck attached and the jaw teeth retracted. Being sure the tang is properly positioned, give the chuck a few smart upward thwacks with a rubber mallet and then check the run out with a dial indicator, using a jobber drill blank you can get from Amazon, etc. The blank should be of useful diameter, 3/8" or so and at least 4 1/2" long. As it has not been worked, it should be perfectly cylindrical and this can be tested if needed by rolling it on a dead flat surface, table saw, piece of glass. Allow a few inches to protrude from the jaws and, with dial indicator in perpendicular contact, rotate the chuck by pulling on the drive belt, drill press unplugged. I can always get ~.003-4 which is satisfactory for drilling wood with large diameter bits but I do have to reseat the taper several times to do so. This is the law of sweat equity,
    Last edited by Bruce Mack; 05-29-2020 at 5:02 AM. Reason: clarity

  7. #7
    Join Date
    Aug 2017
    Location
    Arlington, TX
    Posts
    197
    If the runout triples in the very short distance from the chuck to the bit shank just below the chuck, that sounds to me like the chuck is dirty and/or worn, and should be either cleaned or replaced.

    -- Andy - Arlington TX

  8. #8
    Join Date
    Sep 2016
    Location
    Modesto, CA, USA
    Posts
    4,308
    Sounds like the chuck is bell mouthed and worn. It won't mean much but I would indicate the outer body of the chuck and see if that is better.
    Indicate the shaft of the bit just above the head. This may show a bent shaft on the drill. I would use several drills and see if they are all the same.
    Bill D

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