[pianotech] bridge pin drill speeds

[Encore Pianos]

Hi William:

 

Thanks for your comments.  I do already own a small pneumatic inline drill,
and the thinned poly coiled hoses.  I have thought of suspending the coil
from the ceiling above my worktable as you suggest.  My drill is one speed,
but I can regulate that by controlling the air pressure.  So that remains an
option if I cannot find an electric inline drill along the lines of what Ron
sent his picture of.  I played with the air drill and some bridge stock
yesterday afternoon, and it should work if I decide to go that route.

 

Will

 

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of William Monroe
Sent: Friday, September 30, 2011 9:06 PM
To: pianotech at ptg.org
Subject: Re: [pianotech] bridge pin drill speeds

 

Hi Will,

 

I've drilled with a foredom tool for a while now, and like it a lot.  I
don't use a jig to set the angle, but drill by hand instead.  Once I get a
few unisons in, it's been relatively easy for me to maintain a consistent
angle.  If you had to pick one RPM setting, 2500 is about right, IMO.  With
the foredom, I have always connected it to the variable speed accessory so I
can adjust the RPM to a workable speed.  I suppose in theory I should be
using a slightly slower speed with the larger size drills, but I haven't
found it necessary.  I adjust the speed of the drill at the treble end, and
keep it there for the whole of both bridges.  I have a pneumatic drill that
operates at 2600 RPM, and based upon observation I'd say that's about where
I have the foredom tool set (the foredom tool is adjustable on a dial scale
1-10 which is relatively informative, but precisely useless.  ;-]   )

 

I've have burned a few holes (and bits) in the past while trying to find the
optimal speed, and if memory serves, it doesn't take much above 3500 RPM to
be problematic.

 

I'm surprised that the pneumatic hose seems unwieldy to you.  If you go
pneumatic, the small diameter, lightweight polyurethane coil hoses work well
if you suspend them above the piano (or in your case, workbench since you'll
be out of the piano).  Combine that with a small high speed pneumatic drill
and you're golden.  Like this one:
http://www.amazon.com/Chicago-Pneumatic-CP7300R-4-Inch-Reversible/dp/B000NP0
RC8

 

William R. Monroe

 

On Fri, Sep 30, 2011 at 12:33 PM, Encore Pianos <encorepianos at metrocast.net>
wrote:



To those of you on the forum who do bridge recapping and such, I pose the
following question:  what do you consider to be an optimal RPM speed for the
bridge pin drill bit to be turning at?

 

I have a reason for this question.  In the past I have drilled my bridges in
the piano with the bridge glued on the board, and the board glued into the
rim,using a hand electric drill.  But I am in the process of changing my
bridge capping methodology whereby I am capping the bridge with horizontally
laminated veneers, and this means I will be planning the root to establish
down bearing, and then gluing on the laminated cap of established thickness
to it.  After I plane the bridge root, I will remove the bridge from the
panel (which is held in place by a multitude of screws) to readily glue on
the cap.  I want to take advantage of this access to drill and notch my
bridges as well, and then glue the bridge to the panel, and finally glue the
whole board into the rim.  Given that I will have the bridge off the panel
and attached to a work table, I am planning on making a drilling jig with
the desired drilling angle built in, along with an adjustable depth stop.
The jig would need to use some kind of small inline drill like a pneumatic
inline drill (about 2500 RPM) or and electric inline drilling tool (Dremel
tools 5,000 to 35,000 RPM)

 

Testing on my drill press at 2500 RPM, the pneumatic seems doable.  But the
hose attached to the tool can be unwieldy, so I am leaning towards an
electric tool.  But I am concerned that the speeds of 5,000 RPM up will be
too fast, and burn and expand the hole.  Does anyone have experience using a
Dremel type tool for bridge drilling?  

 

I will happily entertain other suggestions for tools.  Thanks for your
input.

 

Will





 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20111001/3d755529/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/jpeg
Size: 4863 bytes
Desc: not available
URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20111001/3d755529/attachment-0005.jpeg>