Pianotech

Expand all | Collapse all

What is the best hammer boring jig to use for boring hammers with a rake angle?

  • 1.  What is the best hammer boring jig to use for boring hammers with a rake angle?

    Member
    Posted 15 days ago

    I am new at boring hammers and do not yet own a hammer boring jig. Because the way some of my pianos are set up, I may need to bore hammers with a slight rake angle, maybe at 91% instead of the typical 90%, perpendicular angle. From your experience, which are the best boring jigs to use in order to easily bore hammer with a slight rake angle?



    ------------------------------
    Joe Burros
    Cell: 646-410-7174
    jbcello@gmail.com
    www.fmi-newengland.com
    ------------------------------


  • 2.  RE: What is the best hammer boring jig to use for boring hammers with a rake angle?

    Registered Piano Technician
    Posted 15 days ago

    Joe,

    The Brooks, Ltd. fixture is what I have used when I need to bore my own. Although not super intuitive it gets the job done. If they don't make it anymore you can borrow mine. I.normally have them fully prepared at Ronsen. They do a great job. 

    Peter Grey Piano Doctor 



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



  • 3.  RE: What is the best hammer boring jig to use for boring hammers with a rake angle?

    Member
    Posted 14 days ago

    Thanks Peter, I think I'll take you up on borrowing that jig, so I can see if I like it.



    ------------------------------
    Joe Burros
    Cell: 646-410-7174
    jbcello@gmail.com
    www.fmi-newengland.com
    ------------------------------



  • 4.  RE: What is the best hammer boring jig to use for boring hammers with a rake angle?

    Posted 15 days ago

    I'm partial to the jig Ragland Piano sells. It's set up for 15° boring angle in either direction and up to 10° rake. You can put a shim underneath the sacrificial piece to accommodate any thickness hammer molding. Mine came with a reference table of recommended shims for different thickness moldings.

    The only jig I've enjoyed using more is the Kent Gallaway design using a spin index. Unfortunately I don't own one! If anyone happens to have one, I've been thinking of making something similar and references would be wonderful!



    ------------------------------
    Mathias Walters
    North Charleston SC
    (843) 619-7593
    ------------------------------



  • 5.  RE: What is the best hammer boring jig to use for boring hammers with a rake angle?

    Registered Piano Technician
    Posted 15 days ago

    Hi Mathias,

    I have a hammer boring jig that may be what you are looking to reference, although I have not heard of Kent Gallaway in connection with its design. One circular metal plate rotates against another, fixed circular plate to change the boring angle. Sound about right?

    Alan



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



  • 6.  RE: What is the best hammer boring jig to use for boring hammers with a rake angle?

    Posted 15 days ago

    Alan,

    Sounds like it! Who knows, I'm sure there have been all kinds of interesting one-off jigs made. The Gallaway jig was featured in the Jun 1995 journal alongside a few other designs that were commercially available around then. I don't think it had a rake adjustment, but by using a spin index you can get a very accurate angle set.

    Pictures of the Gallaway jig and a generic spin index below.



    ------------------------------
    Mathias Walters
    North Charleston SC
    (843) 619-7593
    ------------------------------



  • 7.  RE: What is the best hammer boring jig to use for boring hammers with a rake angle?

    Registered Piano Technician
    Posted 14 days ago

    Seems I have one of those too.

    Peter Grey Piano Doctor 



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



  • 8.  RE: What is the best hammer boring jig to use for boring hammers with a rake angle?

    Member
    Posted 14 days ago

    Hi Mathias, Thanks for your suggestions. I just watched the Ragland Hammer Boring Jig video, and it looks pretty fussy to use. I guess if you get used to it it's probably not too bad.



    ------------------------------
    Joe Burros
    Cell: 646-410-7174
    jbcello@gmail.com
    www.fmi-newengland.com
    ------------------------------



  • 9.  RE: What is the best hammer boring jig to use for boring hammers with a rake angle?

    Posted 14 days ago

    They sent a little snack bag of hammers to practice on when I ordered it. Once I got a few down, it all clicked pretty well. I put it on a little cross slide table on my drill press for fine alignment -- I can't really imagine using any boring jig without that, but that's me. I usually use one of the spare hammers from the end of each section to make the adjustments I need for that section and have at it. I also replaced a lot of the adjustment screws with hex head screws and I use a T handle hex wrench to adjust everything just to make it feel a little better in my hands.

    Clearly it's possible to do good work on any of them! I've always thought that everyone does their best work when they enjoy the tools they use.



    ------------------------------
    Mathias Walters
    North Charleston SC
    (843) 619-7593
    ------------------------------



  • 10.  RE: What is the best hammer boring jig to use for boring hammers with a rake angle?

    Posted 14 days ago
      |   view attached
    Hi Joe,

    I will email you some information on the Brooks LTD Hammer Boring Jig.

    This is a simplistic jig which we use in our shop to drill all of our hammers.
    Bore distance, Side Angle and Pitch can all be adjusted ....

    Here is info, directions and photos of this simplistic jig.

    Feel free to reach out to us for pricing and questions. 800-326-2440

    Melanie

    --
    Melanie Brooks
    Brooks LTD LLC
    152 Rte 163 Bldg A
    Uncasville, CT 06382
    800-326-2440




    Attachment(s)



  • 11.  RE: What is the best hammer boring jig to use for boring hammers with a rake angle?

    Posted 14 days ago

    I've used the main commercial hammer boring jigs and both have more cons than pros. They either don't rotate on a true axis through the hammer thus as you rotate for bore angle it slightly goes off center. This is really bad on the Renner design because of the rake shelf which takes you either above or below the central axis. The other con of the renner is the feeling of working inside of a box using a little clamp. I always just held the hammer by hand which was quicker.  

    The other designs feature rotating back plates with a cantilevered front shelf. This always has too much flex for my tastes when made out of wood.. If that was made out of steel then that would be the way to go.

    Neither of those designs really address the variable width of the hammers which means the axis of rotation is always off.  I fixed that with a self centering jig. And to be fair my jig is not perfect either. Its made out of wood and i am planning on making an aluminum version. One big improvement when using any of the  jigs is to use the right drill bit.  Brad points flex too much, I use a mill bit which has zero flex and the holes are much more true.

    https://www.youtube.com/watch?v=fdRjM9nv1UE&list=PL4km3jbQ3Am6guVzLlsW5SqDyiHCMtNJL

    -chris



    ------------------------------
    Chernobieff Piano Restorations

    Inventor of Inertia Touch Wave (ITW)
    Advanced Resonant Compression Engineered Soundboards (ARCHES)

    865-986-7720 (text only please)
    ------------------------------



  • 12.  RE: What is the best hammer boring jig to use for boring hammers with a rake angle?

    Member
    Posted 14 days ago

    Hi Chris, I watched your video of the self-centering jig. Looks like it does the job. The Ragland Boring Jig has shims for hammers with different molding thickness. Not sure if the others can be compensated for that also, as I have not used them yet.



    ------------------------------
    Joe Burros
    Cell: 646-410-7174
    jbcello@gmail.com
    www.fmi-newengland.com
    ------------------------------



  • 13.  RE: What is the best hammer boring jig to use for boring hammers with a rake angle?

    Registered Piano Technician
    Posted 14 days ago

    I bought the Brooks jig sometime in the Stone Age, and mine did not come with much in the way of directions.  Of course, that was before writing had been invented.  :-)  I think a decent jig for the money,  But it was not supported at both ends, so there is too much flex for my tastes.  

    I have had the Renner jig, made by Dana Mazzaglia, for probably 25 years.  The hammer clamp is truly half-baked.  It has the sins that Chris describes. 

    Self-centering for the variable widths of our hammer set, is the bane of our existence for all of us.  I spent about $120 for a self-centering vise, but is so inaccurate at centering straight out of the box that it sits unused on the shelf.  Accurate ones cost a lot more.

    Set up is a pain in the butt, so you don't want to have to do it each time you bore a set of hammers.  That means buying an inexpensive new or used drill press as a dedicated work station.  

      



    ------------------------------
    William Truitt RPT
    Bridgewater NH
    (603) 744-2277
    ------------------------------



  • 14.  RE: What is the best hammer boring jig to use for boring hammers with a rake angle?

    Registered Piano Technician
    Posted 14 days ago

    I attached my Brooks fixture to a block of pinblock stock which "improved" its rigidity somewhat. While it's true that this one does not rotate on the center axis of the hammer, all you really need to do to compensate is to pay strict attention to the point of the bit as you begin boring the angled hammers (straight bore is a piece of cake), and tap the jig in the correct compensating direction as the angle increases, then go the opposite direction when you get to the bass section.

    The point is that, though it can a great job, you need to really be aware of what's happening (or not happening) and this takes a bit of practice. 

    EDIT: And the rake angle is easily accomplished throughout.

    Peter Grey Piano Doctor 



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