Conference napalm::commusic_v1

2553.0. "Add-on Drum Pads for Octapad (Pad-8)" by RICKS::NORCROSS (Feedback & Dialogue) Thu Jan 17 1991 19:22

I built a  5-pad  extension  for  my  Pad-8  for  a total of about $40 in
materials.  I am very happy with the  results.    8 + 5 = 13, just enough
for a full octave of notes which is a big  leap  over  just  8  pads when
playing melodic percussion instruments.

Radio  Shack sells "piezo transducers" for  about  $2  each  which,  when
plugged into the external trigger inputs of  a  Pad-8  act as fairly good
triggers.  They offer pretty good velocity sensitivity.  There is quite a
selection to choose from.  Some are labeled as  "buzzers"  or "speakers".
I experimented with 3 different models and found the one  labeled  "piezo
transducer" to have the best response. (Don't know the part number).

The  challenge  is  in  building  a  proper enclosure (pad) for the piezo
trigger.    I  built  my  pads out of plastic "project enclosures",  also
available  at  Radio Shack.  These are usually used for enclosing circuit
experiments, etc.    For me, they happened to be about the right size and
strength (something around 2" x 3" x 1").  All you have to do is tape the
transducer to the inside top of the  box.    Hitting the box triggers the
transducer.   I  drilled  a hole into the side of the enclosure and wired
(soldered) the transducer  to a 1/4" female audio jack there.  This way I
can use  long  or  short cables as needed between the pads and the Pad-8.
Also, I stuffed  the  enclosure  with  2" thick foam in order to hold the
transducer tight against the inside top.

The enclosures are hard plastic, which gives strength, but the surface is
not ideal for "drumming".  I  wanted  a  "padded"  surface.  So I adhered
some 1/4" thick self-stick window insulation strips (essentially foam) to
the top  of  the  enclosure.  To strengthen the surface of the insulation
strips against my  drumming,  I  just covered the self-stick padding with
duct tape.

Cross section from top to bottom:

        -----------------   <--duct tape
        .---------------.
        |               |  <--1/4" thick foam strips, self-stick on bottom
        `---------------'
        .---------------.
        |  `---------'  | <----piezo transducer taped to inside top of box
        |               |
        |               |
        |               |   <-- enclosure (stuffed with 2" thick foam)
        |               |
        |               |
        `---------------'
            `-------'       <---velcro pad

Once the pads were constructed, naturally I wanted to mount them somehow.
While wood alone would provide  a sturdy base for the 5 pads, a hard base
will transmit bumps between pads.   That  is,  you need isolation between
pads for them to be useful.   A  layer  of  rubber or foam under the pads
absorbs bumps.  I tried a mouse pad which seems to work fine.

I didn't want to permanently mount the  pads.    I  wanted  to be able to
physically separate them and move them around.   So  I figured I'd velcro
them to the mouse pad.  I found these  velcro  pads  which  have one side
self-stick (for the  bottom of the drum pads) and the other side screw-in
(for the wood/mouse pad).   That also turned out to be a good way to hold
the mouse pad down.  Another layer of 1/4" thick foam on top of the mouse
pad with cut-outs around the velcro pads rounds things out by holding the
pads level while providing some more cushion.

              +---------------+--------------+------------velcro pads
              V               V              V            (screwed down)

    ----- .---+---. ----- .---+---. ---- .---+--. --- <-- 1/4" foam
    .---------|---------------|--------------|-------.  
    |         |               |              |       |  <--mouse pad
    `---------|---------------|--------------|-------'
    .---------|---------------|--------------|-------.
    |         |               |              |       |  <--wood
    |         |               |              |       |
    |                                                |
    |                                                |  (only 3 pads shown)
    `------------------------------------------------'

Parts List
-----------
  Description               Rough Price Qty  
  ------------              ----------- ---
  piezo transducers          $2    x     5  =  $10
  project enclosures         $2    x     5  =  $10
  female 1/4" audio jacks    $1    x     5  =   $5
  mouse pad                  $5    x     1  =   $5
  piece of 1/2" thick wood   $5    x     1  =   $5
  piece of 1/4" thick foam   $1    x     1  =   $1
  piece of 2" thick foam     $2    x     1  =   $2
  velcro pad pairs           $1    x     5  =   $5
  duct tape
                                            ----------
                         Total Rough Price  =  $43

I got the 2" and 1/4" thick foam from a fabric store.

Enjoy,
/Mitch

  ....can't wait for the MG-510 guitar controller to arrive...

	Mitch,

	Other than cost, why didn't you try practice pads?

	We (my studio partner and I) built up an entire set from a bunch
	of old Simmonds drums, and a Remo practice snare, and rubber Remo
	pads for cymbals. 

	For the snare, I took off the head, and drilled a small hollow under
	it to mount the piezo. A hole to the other side gave the wires a
	place to go. Hot glue to hold the piezo in. Works great and feels
	a lot like a snare.

	The "cymbals" are rubber pads to which the piezos are mounted flush
	to the bottom. Not as nice as the snare, but about 70% cheaper.

	We also took some PVC pipe, and built a set of "woodblocks", which
	we mounted the piezos inside. To dull the things down, we covered them
	with rubber - they make great assignable percussion doodads. 

	Anybody wants more detail, let me know.

	/pjh

At one  point  I spotted a practice "kit" which consisted of about 4 pads
and a kick  pedal  all  mounted on a frame.  It went for about $75 or so.
That would have made  a nice starting point for someone who would like to
recreate the "spacing" of a real drum kit.

In my case, I wanted to  keep  it  relatively  small  and  portable.   As
described in .0, what I ended up  with  is  5 pads on a piece of wood the
size of a mouse pad (about 8" x 11").

Certainly, it is important to get the right  "bounce" and feel out of the
drumming  surface.  The surfaces that I built are satisfactory,  but  not
super -

Where can rubber material be purchased?  I bought the "self-stick  window
strip insulation"  (essentially  1/4"  foam)  from  a hardware store.  It
provides some bounce  back.  Rubber and glue would probably be better.  I
will no doubt continue to experiment and modify these pads.

/Mitch

	In my case I knew someone who works in an electric utility; I got my
	hands on some used rubber mats (1/4" thick) for free. 

	I guess some hardware stores carry rubber mats, also automotive
	stores (funny where one finds musical accessories ;^) )

	/pjh

>Where can rubber material be purchased?  I bought the "self-stick  window
>strip insulation"  (essentially  1/4"  foam)  from  a hardware store.  It
>provides some bounce  back.  Rubber and glue would probably be better.  I
>will no doubt continue to experiment and modify these pads.

I got the rubber that I used for my pads from Green Rubber Co. in Cambridge.  
They sell *every* kind of rubber known to man (no exaggeration).    They pretty
much only sell to large manufacturing interests, but I walked called up,
explained it was a "prototype job" and paid cash on the barrelhead.

FWIW:  I used 1/8" closed-cell neoprene and in hindsight, I wish I had gotten
1/4" thickness.   It cost more, buit I ended up having to double up on the
neoprene to get the right 'feel' so it was probably a wash.

Are you located in the New England area?  If not, then Green Rubber isn't for
you.

/doug