One of the reasons that I’ve not posted anything new recently is that I’ve been learning to play the guitar, and now that I’ve got to the point where I can play some almost recognisable songs, I wanted some accompaniment and bought a cheap electronic drum kit. I took the cheaper option and got a kit that had a mesh snare and rubber toms, but then instantly regretted not getting the full mesh kit as the rubber pads make a lot more noise.

I thought I could just buy mesh replacements but the cheap ones aren’t sold separately and the easily available Roland ones are very expensive. Luckily it turns out that it’s really easy to make them at home. The actual sensor is just a simple piezo element, there’s no active electronics in the pads at all.

The Parts

The basic idea is to take a normal acoustic drum, swap in some mesh heads and add some brackets to hold the piezo sensor. The table below shows all the parts that I used to create four mesh pads, and as you can see the total cost is only £24 per pad. In fact I already had enough scraps of aluminium and the steel brackets left over from other projects, so the actual cost to me was more like £18 per pad.

Qty.	Item	Total Cost	Cost Per Pad
2	8 Inch TomTom	£40	£10
4	8 Inch Mesh Head	£25	£6.25
1	5 Pack of Piezo Pickups	£7	£1.75
1	25 Pack of 40x60x2.5mm Angle Brackets (need 6)	£11	£2.75
1	2x20x1000mm Aluminium Bar	£5	£1.25
1	20x35x1000mm Aluminium Angle	£7.50	£1.88
8	M6 Wing Nuts	?	?
28	M4 Bolts, Nuts and Washers	?	?
	Some scraps of open cell foam (acoustic tile, packing material, etc.)	?	?
	some scraps of rubber sheet (hard mouse pad?)	?	?
Total		£95.5	£24

Two For One

Unlike an acoustic drum, these pads don’t need to sound good, the less noise they make the better. As a result they don’t need a skin on both ends, so we can cut them in half to get two pads out of a single acoustic drum, each with all the necessary tensioning hardware.

Bridge Mounting Brackets

The piezo element will be mounted about 20mm below the centre of the mesh head. It will sit in the middle of an aluminium bridge that will span from one side of the drum to the other. That bridge will sit on 90 degree angle brackets that attach to the existing screws on the sides of the drum shell.

The pictures above illustrate the construction of those brackets. They’re made from 80x20x2mm strips of aluminium, which are bent 50mm along their length. The long edge then has a 4mm wide slot cut to allow the bracket to be moved up and down to adjust the distance of the sensor from the mesh. Two 4mm holes are drilled in the short edge to attach the bridge.

Bridge

The bridge itself is made from a 170mm long piece of aluminium angle. 4mm wide slots are cut for the screws that will fix it to the mounting brackets to allow for slightly different size drum shells. I’ve used 3mm thick aluminium as that’s what I had lying around, but I’m sure thinner and cheaper stuff would be just as good.

Mounting Clamp

The pads need to attach to the 10mm diameter rods that the original pads used. To do this I made clamps out of some steel angle brackets that I had on hand. The idea is to clamp the rod between two steel sheets, each with a groove milled into the face that will keep the pad straight on the rod and stop the rod from being pushed out of the sides when the clamp is tightened.

First one of the angle brackets has the length of one end reduced so that it fits in the drum better. Then a second bracket is cut in half so that we just have a flat sheet left with holes that match the first. 4mm wide grooves are milled into the faces of the brackets. Then two diagonally opposite holes in the flat piece are widened to 6mm to allow the wing nuts to pass through, and the matching holes in the angle piece are tapped with a 6mm thread.

Mounting Clamp Fitting

Next the clamp can be fitted to the drum. First I drilled a 10mm hole 30mm up from the bottom. Then the rod was pushed through the hole and the clamp attached to it so that the clamp was held in the correct position and I could mark the fixing holes. Finally the fixing holes were drilled and the clamp was bolted to the side of the drum shell using M4 nuts and bolts.

Bridge

Next the bridge was installed ready to accept the piezo element. The bridge was positioned so that it’s top surface was 20mm below the top edge of the drum.

Piezo Pickup

For the piezo elements I used cheap acoustic guitar pickups that I found on Amazon. I chose these as they already had 1/4″ jack plugs attached, so I didn’t need to buy them separately.

The pickup casing was discarded so that I was just left with the bare piezo element. The element then sits on a small circle of rubber pad that has a groove carved out of it for the wire and solder joint to sit in, so that it can sit perfectly flat on the bridge. It also provides some isolation so that a 2nd piezo could be fitted for rim shot detection, though I’ve not done that. The rubber I used was left over scraps of 2mm thick mass-loaded rubber sheet that I used when constructing the isolation platform that the drum kit sits on, but I’ve read of others having success using hard rubber mouse pads.

The vibrations are carried from the mesh to the piezo through a piece of foam. I first tried a fairly stiff foam golf ball, but that didn’t work very well. I then tried a piece of acoustic foam tile, which much to my surprise, worked perfectly. I would have thought that as it’s designed to absorb sound that it wouldn’t transmit it very well, but it does.

The rubber pad, the piezo element and the foam triangle are all held to each other and to the bridge by double sided sticky tape.

Done

That’s it! Fit and tension the mesh, clamp the pad to the mounting rod, plug it in and start playing. These pads are so much quieter than the rubber ones, and the neighbours almost certainly won’t be able to hear a thing.