Hank Drum Construction Details and Dimensions

all-hank-drum-notes-laid-outIn a previous post, I introduced the “Hank Drum” and vaguely showed how to make one.  In this post, I’ll go over the dimensions, layout, and the details of how to build and tune this Hank Drum.  As always, I don’t recommend you do anything on this site.

To make this device you’ll need the following:

  • An empty and never used propane tank
  • Calipers (Mine from Amazon), a compass, or some makeshift equivalent
  • Drill and 1/8 inch drill bit (or close)
  • Dremel tool or angle grinder with cutting blades
  • Masking tape
  • Pen
  • Tape measure if you don’t have calipers
  • bungee cord or other strap

Most all of this stuff can, of course, be found on Amazon, but it’s probably easier just to go to your local hardware store to buy it.  The calipers might be an exception depending on what’s available.

Make Your Drum:

Cut the Base Off

This isn’t too hard, but to save wear on your cutter, you can be strategic and cut it into three equal sections away from the welds.  From here, the welds can be partially cut, then bent back and forth until the three sections snap off.  After this, you’ll need to do some grinding to get the remaining weld material off.

Take the Valve Out

First of all, be absolutely sure this tank is not and never has been filled with propane.  I’m not sure if it would explode, or violently shoot the valve off, but don’t take that chance.  This technique came from the generally unreliable website*, “ehow”, and involves closing the valve, heating the threads to loosen the liquid weld, and wrenching on it really hard using a cheater bar.

propane-valve-loosen-attempt

Fortunately, no one saw this craziness

I used a pipe wrench, and a trailer hitch from my truck as a cheater bar.  To hold the tank still, we strapped it down to two trees in my front yard, and I donned a paintball mask (not the first time).  You know, just in case.  I live in South Carolina** so that kind of thing is pretty normal here.

Layout your drum

There are probably an infinite number of ways to lay this puppy out, but our first step was to find the center of the tank using a pair of calipers.  If you draw several arcs from the circle left over from the base at approximately half that diameter, they should intersect at the center.

From here use the edge of your caliper, or a compass to scribe a circle.  We selected a 2 inch radius for a 4 inch inner diameter.  The outside was scribed in a similar manner at 3 inches in radius for a 6 inch diameter hole pattern.  We used tape to approximately lay lines out 4 sets of lines 2 inches apart and the edges were traced with a sharpie.  We then used a punch to make a center indention in the corners where we wanted to drill.

Start Cutting!

all-hank-drum-notes-laid-out

Hank Drum with cuts laid out

The first cuts will be 8 holes at the corners of your long (deep) notes.  I used a 1/8 inch drill bit because it was easy to cut, and seemed wide enough.  Once these are done, use a Dremel Tool or other grinder to “connect the dots” and cut a few inches down the side of the drum.  An inch or so if fine, we’ll be tuning these notes by lengthening them, so it’s important not to cut too much.

Higher Notes

In this layout, there are 4 higher notes that start out at a 6 inch diameter.  Repeat the layout and cutting steps again, but turn everything at 45 degrees from the “long” notes.  Also, be sure not to cut too deep.

Tuning

Now that you have everything started, you’ll undoubtedly start testing everything out.  To start tuning, you’ll probably want to wrap some sort of a bungee cord toward the base of the tank.  This will help keep one note from making the others ring out too much.

My musical skills are relatively weak, but we basically tuned this by taking a deep note, and tried to cut everything based on this.  In the picture, the A3 note is about 3 inches long, and we tried to make the other notes C5, B3, A4, E4, F4, C4 and B4.  Note that the wider notes will be deeper if cut to the same depth.  If it’s too high, you simply cut lower.  You can always drop the scale a note lower if you mess it up.

If you’d like something a bit less experimental to go by, here’s a template here to use with a D minor pentatonic scale.  I personally like the idea of having straight lines on the top – as it seems easier to cut, but that should at least give you the general idea of where to start cutting.

More Videos

Here’s a video of Jackson tuning the Hank Drum, and another video of it being played before it was finished.  Be sure to see the first Hank Drum post for more background on this device, and a really cool time-lapse video of our initial build.

For another Jackson/Jeremy homemade instrument, check out the Whamola that we made a year or so ago!

*ehow, with such quality articles as “How to Measure Current With a Volt Meter.” – Just search for it, as I really don’t want to add an inbound link to this article.

**We just got internet here 2 1/2 years ago, and that’s when I started this blog.  I’m seriously thinking about upgrading to a 56k modem, do you guys think it will be worth it?  They’re 11.54 from Amazon, but I don’t know, 33.6k is pretty good.  Let me know in the comments.

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