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Searching for Pinblock Drill Bit

  • 1.  Searching for Pinblock Drill Bit

    Registered Piano Technician
    Posted 01-21-2018 14:31
    Posting for a colleague:

    Seeking source for custom drill bits. Specifically, fast spiral, high helix bits for drilling pinblocks.  More specifically, a size or sizes between an E (.250) and an F (.257).

    John Minor, RPT
    University of Illinois School of Music
    jminor@illinois.edu


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    John Minor
    University of Illinois
    jminor@illinois.edu
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  • 2.  RE: Searching for Pinblock Drill Bit

    Posted 01-21-2018 15:12
    There is none. Unless you can find a 6.5 mm bit. I usually use an F bit for most of the block and a G for the top half octave or so. But it's been a while since I drilled a block. AN F bit produces a nice feel, why would you want something tighter?

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    Regards,

    Jon Page
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  • 3.  RE: Searching for Pinblock Drill Bit

    Posted 01-21-2018 16:57
    Bit sizes are highly dependent on drilling equipment, block fabrication, length of pin, and drilling speed to name a few. I have spent much time trying to nail a mid-range torque that is reasonably consistent pin-to-pin, and that does not loosen up too much, after one or two years.

    Experimented with high precision machines, timed plunges, metric between size bits...you name it. The inconsistency remains no matter the configuration of the equipment, including double drilling. Not sure what your end game is, but trying to target an "ideal" torque from the get-go, will probably (note the probably) end up too loose  too soon. Also torque reading with and without string tension on pin will increase by apprx 25inlb from a pin with no string load.

    I have accepted a tighter block to start with, and learned to tune a tight new block with a longer length (15.5") lever.

    If you want to experiment with in between sizes, Guhring has series 549 bright fast spiral bits in the entire 6.0-6.9mm in-between area you are looking for. Quite expensive and shipped from Germany, two day delivery. I get my Guhring bits ordered and from Butler bros  207 784-6875. Very nice bits though.

    Another option is, if G is too loose, use a longer pin and set the pin down deeper. Down side on this is, static friction will increase at the bottom of the pin. This is a pain to tune, as the pin will have more internal twist to compensate for. One wants the tightness up at the top 10mm of the block surface, not at the bottom of the pin.

    However, anyway we collectively skin the cat...we lose...Goldilocks torque in a new block, that is, Goldilocks torque that does not become a marshmallow in 2 years is elusive. And...all the above changes somewhat, depending on the area of the country the piano is drilled at and that the piano lives at...and the RH control of the building. For these reasons, as I mentioned above, I shoot a little tight, exercise the pins if necessary,  and use a long stiff lever to tune.

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    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
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  • 4.  RE: Searching for Pinblock Drill Bit

    Posted 01-21-2018 18:12
    One other thought...

    I have gone back to a Nossaman style Delignit(10mm) capped multilam block. This, because the Delgnit requires a larger diameter bit than the multilam. This means, that the delignit, up at the top of the block is tight to the pin, and the multilam, which is drilled with larger than you would if it were a solid multilam block, is stabilizing the pin foot, not grabbing it for dear life. The benefit is a pin that overcomes static friction at the top of the bock while the bottom of the pin comes along for the ride without adding additional twist to the pin foot.

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    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
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  • 5.  RE: Searching for Pinblock Drill Bit

    Registered Piano Technician
    Posted 01-21-2018 20:28
    I use a .250" rotary knife to drill Bolduc blocks. It is a single flute bit. I drill at quite slow speed so drilling a block takes most of a day. I got mine from Dean Tatham who taught me belly-work. Dean worked with David McChord in Boston. It is a custom made bit I believe.

    Tuning pins vary in diameter and roundness enough to make developing truly consistent feel with high density blocks nearly impossible. When I used AMSCO pins I would like the whole set into treble, tenor and bass pins. Small, medium and large. The Fly pins from Germany are consistent enough I don't mike them.

    I believe the best tuning pin feel results when the pin is tightest at the bottom of the block. That allows one to work a slight torsional deformation in the pin for the last stabilization when tuning. That is why most tuners move the pin up and down slightly in a rotational fashion for the final pin setting motion. To work the pin until you feel the pin "bend" in a torsional way. Torsion bends can be much more stable than flag-polling bends.

    When chip tuning I work any overtight pins down and back a whole step or so being careful not to do this so fast the pins become jumpy. This is the way Steinway NY did this for many eons. I don't know what they do presently.

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    Edward McMorrow
    Edmonds WA
    425-299-3431
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  • 6.  RE: Searching for Pinblock Drill Bit

    Registered Piano Technician
    Posted 01-21-2018 22:01
    Ed,

    I never heard of such a thing. Can you post a picture of this?

    Pwg

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    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
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  • 7.  RE: Searching for Pinblock Drill Bit

    Posted 01-21-2018 22:56

    Ed's bit...I took a pic a couple of years ago visiting his shop

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    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
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  • 8.  RE: Searching for Pinblock Drill Bit

    Registered Piano Technician
    Posted 01-22-2018 08:39
    Okay, I get it. It's an auger bit. Had not thought about using such an animal.

    Pwg

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    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
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  • 9.  RE: Searching for Pinblock Drill Bit

    Registered Piano Technician
    Posted 01-22-2018 11:09
    John,
    After you have drilled the largest diameter drill before the final cut, use chucking reamers to finish the job. You can get them in many sizes in-between standard drill sizes.
    Roger





  • 10.  RE: Searching for Pinblock Drill Bit

    Registered Piano Technician
    Posted 01-22-2018 11:26
    Roger,

    Are you saying to power-ream this or use the reamer by hand?  These things can make an awful mess in wood if not carefully controlled. What is your method?

    Pwg

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    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
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  • 11.  RE: Searching for Pinblock Drill Bit

    Registered Piano Technician
    Posted 01-22-2018 11:56
    Thanks for posting the picture Jim.

    The picture doesn't capture the detail of the outer cutting edge. The first cut in the wood is a score around the circumference before the chisel cutting edge lifts wood out of the surface and onto the spiral flute. In other words the bit cuts in two directions, first cut is perpendicular to wood and second cut is angled 30 degrees or so above the plane of the pinblock surface.

    The fluted section between the cutting end and the chucked end is reduced from .025". So no rubbing friction. One must use a drill press with this bit otherwise the bit will wander away from drilling a perfectly straight hole.

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    Edward McMorrow
    Edmonds WA
    425-299-3431
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  • 12.  RE: Searching for Pinblock Drill Bit

    Registered Piano Technician
    Posted 01-22-2018 12:13
    Peter,
    I'm assuming any pin block drilling is performed on a drill press  -- reaming also, I've always limited my reaming to no more than .020" increase from the original hole. Maybe that's where you've had trouble. Reamers are not drills, and as such need to be limited to a very small incremental cut. Also. I use the next to the slowest speed on my drill press. Unfortunately, the belt setting/verses chuck speed diagram is missing from my drill press, so I can't tell you what speed I use.
     
    Roger
    P.S. Also, do not cut shorter, the long shank associated with reamers. They need the ability to follow the original hole. A short shank will cut it's own hole.





  • 13.  RE: Searching for Pinblock Drill Bit

    Registered Piano Technician
    Posted 01-22-2018 19:55
    I am glad that I am not the only one who has struggled with this problem.  I had wondered if I was doing something wrong when drilling a new pin block.  Sometimes they are still great after 4-5 years, other times they are not as tight after 2-3 years, and quite inconsistant.

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    Clarence Zeches
    Piano Service Enterprise School of Technology
    Toccoa GA
    706-886-4035
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  • 14.  RE: Searching for Pinblock Drill Bit

    Posted 01-22-2018 15:50
    I have drill bits made by Bolduc at .257 3 1/2" and 6" if it helps.

    Brooks LTD
    800-326-2440

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    Melanie Brooks
    Brooks, Ltd. Piano Products LLC
    Uncasville CT
    860-848-6605
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  • 15.  RE: Searching for Pinblock Drill Bit

    Registered Piano Technician
    Posted 01-23-2018 18:33
    If you haven't tried McMaster Carr, they are a good source for drill bits, etc.

    Bob Anderson
    Tucson, AZ