The Xylophone Project

When I started this project I had already been interested in building a xylophone.? I had done some research and had an idea about what I’d need to.? Let me tell you, I had no idea what I was in for.? See, I’m not OK with just OK.? If I build something, it’s going to be good.

A local school that I had done a few drums for in the past contacted me about possibly building a set of xylophones for the music room.? I chimed in with “yeah, of course, I’ve not really built one, but I know how!”.? Well, that was quite naive of me.

After lots more research and designing / laying out digitally I came up with a design that I felt was unique, and well suited for a xylophone.

My first step was to build the box.? My rough maple lumber was a bit over one inch thick, and I wanted to do my box walls at half an inch, so instead of planing down the lumber to half an inch, I took to the new bandsaw to resaw the maple in half.? It worked out really well, and let me use the same board for each side of the box.

After I worked out the angles (yeah, the box isn’t square, so a 45 miter just doesn’t cut it) The next challenge was to inset the bottom.? This is what I feel makes this xylophone special.? I’ve seen many that just have a straight slope, but I wanted something more organic since the curve of the notes resonance isn’t a straight slope.? Not only was I fitting in a trapezoid shaped bottom, but it was curved.? I cut the shape out of a scrap and used this as a router guide to cut a 1/8″ slot on each side of the box for the bottom plate to slip in to.

While working on the box, I decided to go ahead and rough cut all the keys to size.? This process was pretty straight forward as I’m very used to cutting slats.? I went ahead and marked the keys destined tone because they were all very close in size.. this way I wouldn’t mix them up.

After getting the xylophone boxes grooved out for the bottom plate, I also had to groove out for the tone separators.? My plans called for three separate resonator boxes within the one box.? This way it will maximize the tones of each set of keys.? I went ahead and glued in the bottom plates in – this was a the most difficult part of the process.? I had cut some padauk planks down to 1/8″ to fit in the curved 1/8″ grooves of the boxes.? I thought about soaking the padauk to make it more plyable, but it was easy enough to bend into the shape I needed.? However, getting the bottom plate in while assembling the rest of the box around it was quite challenging and took up a lot of clamps!

Once the xylophone boxes were all glue up, I wanted to add some strength the the miter joints since the wood was only 1/2 inch thick.? I figured I would go a head and make it decorative too, so I made a little jig for cutting splines on the table saw.? Then I used the padauk to make small triangles on the bandsaw to slide into the slots I cut.

It came out really nice.? It looks clean and professional.? I loved it!? Up until this point I wasn’t sure what to expect as I’m not really a box builder – but this was inspiration for me to keep going!

Meanwhile I was working on turning those padauk blanks into xylophone keys.? I had no idea what I was in for with tuning these.? Lets just say I’m glad I cut a few extra!? The holes drilled out have to be in a specific spot relative to the length of the key.? 22.5 percent of the total length of the key, on each end.? I made a little template for each key since I was doing 4 sets.? The holes also have to line up perfectly on the box, so that they sit in the middle of the 1/2 inch board.? This special spot on the key is called a node.? It’s where the keys vibration is nullified.? Having the key rest on this specific point, as well as drilling it there means that the resonance will be open and full.? A little bit off and the key sounds dead.

To tune the keys, in a very simplified manner, you take wood off the bottom of the key to tune it lower.? If you go too low.. well, you dont have a lot of options other than to make a new key.? Taking a little off the top corners will bring the pitch up slightly, as will taking some off each end – but that shortens the key and will change the position of the node that is already drilled out – it will also make the key not flow visually in the rest of the xylophone.? I started with the smallest keys and tuned them up with a drum sander on my drill press.? If I ever build these again I am going to invest in a good osculating spindle sander!? As a side note, paduak is very oily and will stain your clothes, hands, nose hairs and the whole shop when sanded like this.

Once I found out how much I could take off, I started using the band saw to cut the key down leaving enough room to do a fair amount of sanding to get it to final dimension.? This was a big help for the larger keys as there was much more to take off than with the smaller keys.

After the keys were all tuned up fairly close I let them sit for a day.? The heat from sanding them lowered the pitch I was getting some changes in tone.? When they cooled back to room temp they came up about 5-6 cents.

I did a final tune and then tested a key all the way through to final sanding and oiling.? The final sanding (hand sanding to 220 grit) dropped the note about 5 cents, and oil dropped the note another 5 cents… so I let the key dry and sit for a few days.? It came back up but was 5 cents short of where it started, so I tuned all the keys 5 cents high – then sanded, oiled them with some diluted linseed oil, and let them sit. for a few days.

Meanwhile I finished up the boxes, added the separators and sanded / oiled the xylophones in the same manner as the keys.

I thought the mallets would be easy – nope.? I tried different hardnesses of rubber balls, chair legs, corks, ect.? Finally found some hardwood balls that sounded pretty good, so I drilled centers and put 1/4 inch maple dowels in them.

All in all this was a really fun project.? Frustrating, yes, did I learn a lot… YES!? and I did enjoy the process and love how they sound / look.? I’m not sure if I want to offer these for sale yet or what I’d ask for them… but it wasn’t really about that to begin with.? It was more of a personal challenge.? I’m so pleased with these xylophones I hate to call them “xylophone”.? To me they are mini master-crafted marimba boxes. :)?? Let me know what you think of them!