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Air cooling drill bit / tuning pin angle

  • 1.  Air cooling drill bit / tuning pin angle

    Posted 22 days ago
    Greetings,
    I am trying to find a flexible air cooling system for my drill press. A search mostly shows wet systems for milling and lathe machines. Any suggestions where I can find a selection is greatly appreciated.

    Also, I have been drilling tuning pin holes on a 7 degree, as prescribed in the Reblitz book, for many years and I'm not to pleased with the lower coil running down the pin angle. Do any of you go to that angle or a lesser angle maybe 5 degree perhaps?

    ------------------------------
    David Chadwick
    Newark OH
    740-610-6695
    ------------------------------


  • 2.  RE: Air cooling drill bit / tuning pin angle

    Posted 22 days ago
    Edited by Karl Roeder 22 days ago
    Mr. Chadwick,
    Pianotek sells a vortex chiller call the Cold Gun. It comes with plastic Loc Line coolant hose assembly that is flexible enough to configure and rigid enough to stay put. The Cold Gun needs dry air so you may want a line drier between your compressor and the chiller. I typically drill new blocks at 5 degrees as that matches most of the factory production I'm replacing. I've never found 7 degrees to be workable not least because it makes closed coils impossible. I also find that most of the 7 degree blocks I replace (always by a prior rebuilder) have pins hitting the plate.

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    Karl Roeder
    Pompano Beach FL
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  • 3.  RE: Air cooling drill bit / tuning pin angle

    Posted 22 days ago
    Thanks Karl,
    I had checked Schaff's Webstore and found nothing so I figured (wrong) about Pianotek.

    I will be changing my drilling angle to 5 degrees. And you are right again..... the tuning pins hitting the plate and deforming the bushing is another drawback. Thanks for you input!


    ------------------------------
    David Chadwick
    Newark OH
    740-610-6695
    ------------------------------



  • 4.  RE: Air cooling drill bit / tuning pin angle

    Posted 22 days ago
    Edited by Ed Sutton 21 days ago
    Search double drilling pinblock on this site.
    If you double drill you won't need a vortex chiller. The bit doesn't get very hot.

    ------------------------------
    Ed Sutton
    ed440@me.com
    (980) 254-7413
    ------------------------------



  • 5.  RE: Air cooling drill bit / tuning pin angle

    Posted 21 days ago
    Ed,
    I have been thinking of double drilling. I have read some posts that tech's are pleased with the condition of the final pass and comments of controllable and consistent pin torque. I'm going to drill some samples.

    ------------------------------
    David Chadwick
    Newark OH
    740-610-6695
    ------------------------------



  • 6.  RE: Air cooling drill bit / tuning pin angle

    Posted 21 days ago
    Air chillers are not really necessary. I've been using a simple Loc-Line set up to direct my shop compressed air -- theoretically regulated to 90 lb/ft2 -- for years. 

    See: http://www.loc-line.com/ 

    The ideal tuning pin back angle has been debated for years. Many reasons for the extreme back angles favored by Steinway (and a few others) have been offered. I can only suggest that you do the geometry (as I have and as I have published in the Journal -- if you are desperate I can probably find the drawing and convert it to a PDF file or a *.jpg image and send it to you. ). Early three-ply pinblocks were good at holding torque but not so good at structural stability.

    As string tensions increased, and especially when the string frame casting covered the pinblock (leaving a considerable distance between the top of the pinblock and the string) the pins tended to pull toward the direction of tension. Wood fibers got crushed and sections of wood split. A solution for this was to make the holes through the casting relatively small and increase the back angle of the pins. Thus, when the tuning pins drifted forward they would butt up against the bottom of the tuning pin panel and be held there. They could drift no further. These pianos were designed such that most, or all, of the tuning pins would be in contact with the casting.

    Let me repeat, these systems were designed such that the tuning pin would rest against the bottom of the hole and yet appear to be nicely centered at the top of the hole. 

    Modern multi-ply pinblocks do not generally suffer from this problem so the back angle can be decreased. Particularly when plate bushings are used. My preference is to see the string leaving the pin at approximately a 90 deg. angle. 

    ddf 

    --
    Delwin D Fandrich
    Fandrich Piano Company, Inc.
    Piano Design and Manufacturing Consulting Services -- Worldwide
    6939 Foothill Ct SW -- Olympia, WA 98512 -- USA
    Phone 360.515.0119 -- Mobile 360.388.6525





  • 7.  RE: Air cooling drill bit / tuning pin angle

    Posted 21 days ago
    I just have a section of metal flexible hose with a rubber tip on it that I connect to my air compressor pointed at my drill bit. I always do the double drill thing - first pass with a quarter-inch bit and the second with the final diameter bit. I use the air on my bit, not so much for cooling, but rather to keep the wood chips clear so that I can see what I am doing. However, I do think the air helps on the first pass to cool the initial bit. Photo - or rather video (I didn't have a decent photo) - attached.

    Regarding drilling angle, I basically do what Del does. With coil height determined, measure the approach angle of the string. Drill perpendicular to that angle. I figure that even with my Delignit-capped pinblocks, the pin might lean a degree or so from the original drilling (not that I've actually ever positively determined that), so I do tip the drill bit back one degree. I figure that isn't going to create any problem with the coil wanting to run down the tuning pin. Photo of results attached.

    Where this 7 degree thing ever originated, I have no idea. Five degrees may or may not be optimal - all depends on the plate configuration. I recently drill a couple S&S L blocks - I think they were drilled at 3 degrees - that gave me my one degree lean-back from the string approach angle. I use the little square digital angle measuring device to determine my angles - works like a charm.

    ------------------------------
    Terry Farrell
    Farrell Piano Service, Inc.
    Brandon, Florida
    terry@farrellpiano.com
    813-684-3505
    ------------------------------

     Video


  • 8.  RE: Air cooling drill bit / tuning pin angle

    Posted 21 days ago
    So, Terry, you drill in the piano, but without the plate installed.  I like the idea of that, it would eliminate the potential for damaging the plate finish, and make it easier to move the drill from section to section past the plate struts.  At what point did you punch-mark the hole locations - while fitting the block to the plate?  Or after installing the block and plate in the piano then removing the plate for drilling?

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    Michael Spalding RPT
    Fredonia WI
    262-692-3943
    ------------------------------



  • 9.  RE: Air cooling drill bit / tuning pin angle

    Posted 21 days ago
    Michael S. wrote: "So, Terry, you drill in the piano, but without the plate installed.  I like the idea of that, it would eliminate the potential for damaging the plate finish, and make it easier to move the drill from section to section past the plate struts.  At what point did you punch-mark the hole locations - while fitting the block to the plate?  Or after installing the block and plate in the piano then removing the plate for drilling?"

    Pinblock was fully installed in the case. Plate was fully fitted to block and in place when I marked the hole locations.  I use a self-centering punch - really gets the centers dead-on perfect. Then I removed the plate for drilling.

    I guess I've done in both ways - plate in or plate out. On a plate without tuning pin bushings, I don't see any advantage to having the plate installed while drilling. On plates with bushings, I do leave the plate installed so that I can drill through the bushing - I let the bushing be my bit-centering guide.

    ------------------------------
    Terry Farrell
    Farrell Piano Service, Inc.
    Brandon, Florida
    terry@farrellpiano.com
    813-684-3505
    ------------------------------



  • 10.  RE: Air cooling drill bit / tuning pin angle

    Posted 21 days ago
    You don't need to air cool if you double drill.  Make a first pass with a 7/32" drill or similar and then make a second pass with the final size.  It's taking out so little material that the bit won't heat up on the final pass.

    ------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    ------------------------------



  • 11.  RE: Air cooling drill bit / tuning pin angle

    Posted 21 days ago
    David,
    You're correct, double drilling is a common procedure in machining. Although in machining, when precision is required, a chucking reamer is used to remove a small final cut of material without creating excessive heat that could distort the final cut.
    Roger





  • 12.  RE: Air cooling drill bit / tuning pin angle

    Posted 20 days ago
    I suppose a reamer in the case of machining might be more accurate but I don't think we need quite that kind of accuracy and using a reamer requires getting the initial hole extremely close to the final size.  In this case a first pass of almost any sized drill is adequate.  I use a drill bit for the second pass.  Your final drill bits will also last longer doing it this way.

    ------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    ------------------------------



  • 13.  RE: Air cooling drill bit / tuning pin angle

    Posted 21 days ago
    Is there no advantage to keeping the bit used in the first of the two passes from heating up? Or is this only a concern on the second, final pass in terms of the condition of the walls of the holes and the consistency of diameter?

    Alan

    ------------------------------
    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
    ------------------------------



  • 14.  RE: Air cooling drill bit / tuning pin angle

    Posted 20 days ago
    Alan E wrote: "Is there no advantage to keeping the bit used in the first of the two passes from heating up? Or is this only a concern on the second, final pass in terms of the condition of the walls of the holes and the consistency of diameter?"

    In the first pass, bit temp is not a concern because one is not concerned that every hole is exactly the same diameter - close enough is good enough. I like to use my "chiller" (although all it is is a directional exhaust from my compressor) to move the chips out of the way so that I can see what the heck I am doing. If it keeps the bit on the cooler side, that's okay also.

    On the final pass I don't know that it makes much difference. I do use my "chiller" (compressed air blowing away the chips, aimed at the bit) because it is already mounted on my drill press and what the heck. So it goes. Works for me.

    ------------------------------
    Terry Farrell
    Farrell Piano Service, Inc.
    Brandon, Florida
    terry@farrellpiano.com
    813-684-3505
    ------------------------------



  • 15.  RE: Air cooling drill bit / tuning pin angle

    Posted 20 days ago
    The concern with the drill bit heating up is dimensional and burning the inside hole.  Since you are doing a second pass that's not a concern.

    ------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    ------------------------------



  • 16.  RE: Air cooling drill bit / tuning pin angle

    Posted 20 days ago
    I don't like two pass drilling. Probably because I'm not good at it. How do you center the second hole accurately? The pianotek chiller is admittedly pricey but a similar tool can be found on amazon for as little as $49. If I'm already using the compressor to blow air at the bit it doesn't take much additional effort to add in the chiller.  Maybe if I used delignit or other multi-lam material I'd learn how to get better at two step drilling but for now it's just not worth the extra time and frustration.

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    Karl Roeder
    Pompano Beach FL
    ------------------------------



  • 17.  RE: Air cooling drill bit / tuning pin angle

    Posted 20 days ago
    Edited by Jim Ialeggio 20 days ago
    I agree with Karl...I prefer a single accurate pass. I use a chiller because I have one. Compressed air might be fine alone, as its pretty amazing how effective a simple stream of air is at drawing heat away from the bit.

    I tried double drilling in numerous permutations, and I did not find it to be an improvement, in any type block. However, the reason has more to do with my machinery than the concept. All of this discussion is machinery and tooling dependent, so when someone reads these posts they should keep that "machinery & tooling dependent" attribute in the front of their minds.

    When Ron described his double drilling, he only realized after some time of advertising the technique, that the slop in his beat drill press quill was an essential attribute of the success he experienced. As well, he also either did not realize or perhaps communicate how important the very long bit he welded up was to the effectiveness of his set up. Why?...the sloppy quill and long bit allowed the slop in the system to "find" the 1st pass hole. A more accurate machine setup, would force its "opinion" into the 2nd pass, giving a rather inconsistent sized hole.

    Looking at Terry's fine system, I'm pretty sure he has achieved the "let the machinery conform to the location of the first pass itself" attribute. As he moves the floating drill head, I do not see him locking it down for the plunge. The bearing setup on the ceiling, the distance from the bearing tracks to the head help allow the necessary give in the system, and the drill head itself is a light duty Jet or Grizzly type head (I believe). All these attributes allow the 2nd pass to better follow the 1st pass hole.


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    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
    ------------------------------



  • 18.  RE: Air cooling drill bit / tuning pin angle

    Posted 20 days ago
    I have long used the shop vac with long narrow nozzle set up very close to the bit. That gives me plenty of air flow to cool the bit (as long as I don't try to drill the block in 30 min) AND sucks up the majority of the chips at the same time.  Has worked quite well. I test the bit temp from time to time with my fingertips. If I need to slow down I do.

    Pwg

    ------------------------------
    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
    ------------------------------



  • 19.  RE: Air cooling drill bit / tuning pin angle

    Posted 19 days ago
    Jim I. wrote the following quotes: "Looking at Terry's fine system, I'm pretty sure he has achieved the "let the machinery conform to the location of the first pass itself" attribute. As he moves the floating drill head, I do not see him locking it down for the plunge."

    Correct, I do not lock anything down. And thanks for the compliment! The drilling angle is already locked in, so the second pass is exactly the same angle as the first.

    "The bearing setup on the ceiling, the distance from the bearing tracks to the head help allow the necessary give in the system, and the drill head itself is a light duty Jet or Grizzly type head (I believe)."

    Craftsman from Sears Roebuck as a matter of fact! $79 special! However I did put a $100 Jacobs chuck on it - runout is minimal.

    "All these attributes allow the 2nd pass to better follow the 1st pass hole."

    Boy, for the life of me, I wish that I could honestly say that I planned an intricately calculated system that would promote good following of the bit on the second pass - but I didn't. It just worked out. The wheels on the tracks, etc. just seem to have the right resistance to movement and an ease of movement such that I can easily work the unit very close to the hole and when the bit touches the hole it seems to self-center perfectly. I've never been able to observe any enlargement at the top of the tuning pin hole where the second bit wandered a little - it seems to just see the hole and slides right in. It is a pleasure to use.




    ------------------------------
    Terry Farrell
    Farrell Piano Service, Inc.
    Brandon, Florida
    terry@farrellpiano.com
    813-684-3505
    ------------------------------



  • 20.  RE: Air cooling drill bit / tuning pin angle

    Posted 19 days ago
    Simple, you leave enough material that perfect centering isn't that critical and you pay attention.  It's not much different than hitting the target with a single pass.  I've never had a problem.  I find that the result is more accurate (torque comes out more uniform) because you don't have to worry about feed speed or drill temperature, or a chilling set up for that matter.  The holes come out very uniform.  But to each his own, it's all unknown....

    ------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    ------------------------------



  • 21.  RE: Air cooling drill bit / tuning pin angle

    Posted 19 days ago
      |   view attached
    My setup was a small, cheap drill press, modified to let the head rotate 180 degrees to the back of the base. A hole cut through the belt cover let the head slide down the post, effectively turning it into a small cantilever drill press. This was attached to a hardwood plywood double panel, piano hinged to allow angle adjustment. A medium density fiberboard panel braced with aluminum beams rested across the piano. I tried Ron N's compressed air float system, but it didn't work that well. I believe I lubed the bottom of the plywood with ProLube.
    I did first pass with a 3/16" bit, second with a final size bit. The second bit did a nice job of centering and the results were very even torque tuning pins. It was also fun, a stress free part of pinblock replacement that I really miss.

    ------------------------------
    Ed Sutton
    ed440@me.com
    (980) 254-7413
    ------------------------------



  • 22.  RE: Air cooling drill bit / tuning pin angle

    Posted 19 days ago
    Ed,

    My rig is virtually identical to what you describe. Only real difference is that the angle is fixed at about 5 degrees.

    I started out at 7 degrees back when I originally made it, didn't like it (for all the reasons given at the outset), reduced it to 6 degrees (better, but still not what I saw in good factory jobs), reduced again to 5 degrees and now I'm happy with it.

    I have long drilled with the plate in the piano. I think I will try it next time (coming up shortly) with the plate out as was suggested.

    Pwg

    ------------------------------
    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
    ------------------------------



  • 23.  RE: Air cooling drill bit / tuning pin angle

    Posted 12 days ago
    I'm sure it goes without saying, but it's something I tend to forget about ... A dull drill bit gets a lot hotter than a sharp one.

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    Neil Vanderschaaf
    Round Rock TX
    512-577-1840
    ------------------------------