Drum Tuning Turntable

My company recently put out a reminder to us all about “social media”. Basically, not too heavy handed; we can mention the name of the company – I think it’s best not too, though – but should be circumspect about what we say. I suppose that means no controversial comments. Dang. Also, we’re supposed to put a disclaimer in. Here’s mine:

Any comments I make about flying are my own and truthful. They should NEVER be taken as criticism of my company under any circumstances.

Have you ever tried to be neutral in a dispute? Interestingly, if you declare yourself neutral, you’d expect people not to bother trying to persuade you to their side, wouldn’t you? You’d think they’d leave you alone, as “unpersuadable”. Not the case. One ends up being treated with suspicion; getting it from both sides. A third way? Does not compute. What dispute am I talking about? All of them.

Fortunately, I can get in my workshop and turn the world off for a while.

It was time to put the drums back together.

So I made this… 


I call it a Tuning Turntable. I saw a version on a website where there was some advice on how to tune drums. I think it was the Drum Workshop site. Seemed like a good idea. The alternative is to have the drum scraping about on the floor. Also, it’s an interesting little project. A lot of my woodworking these days seems to be “utilitarian devices”, rather than pieces of furniture and the like. The picture above shows it in the “normal” position.

In aviation terms, normal has several meanings. If something – a switch or control, for instance – is in the position where it’s most useful or spends the most time, it’s said to be in its Normal position. Usually such a control will have two or more other positions. If selected to an alternate position, one says that position. For example, we have a Standby Hydraulic Pump. It comes on automatically if the left engine driven hydraulic pump fails. The switch for it is a “push in push out” toggle switch. For cruise flight, it is pushed out, there are no lights on, so it is in the Normal position. In this case, if the engine pump fails, the standby pump kicks in and the lights in the switch come on to let you know. The switch is still pushed out, though; it can’t operate itself (others can). For  takeoff and landing, the pump needs to be running, so the switch is pushed in, the lights come on, and it is said to be in the On position.

Another use for the word normal is to describe one of the three axes. The axis that runs from nose to tail is the longitudinal axis, or roll axis. The one running left to right is the lateral axis, or pitch axis. But the one running top to bottom is the normal axis, or yaw axis. You’d think it would be the vertical axis, wouldn’t you? Vertical has only one meaning though (re this topic) and that is in line with the direction of the Earth’s gravitational pull. Think about it. Each axis remains perpendicular to the other two. Aircraft move freely in three dimensions. Enough clues.

This is the turntable in the closed position… 
I didn’t draw this out before I started. I had some CLS lying around, so just chose a couple of pieces which were big enough and not too twisted. By “big enough”, I mean I used the dimension of the biggest drum I’m ever going to tune; that would be the bass drum. Placed the hoop on a piece and marked it with a bit spare.

Two long pieces were put side by side, a centre line marked, then separated at the  marked X… 

 

 

The upper left and lower right parts will make one set of arms and the remaining pieces will be marked in the same way and make the other set.

Each end was marked for a kind of lap joint and the area X cut away… 

 

Cutting across two surfaces is easy. First, look at both lines in such a way that they look like one line, like this… 

 

…not like this… 

  

Start cutting at an angle… 

  

I look directly on the saw with both eyes… 

  

This seems to give a double image, but I find I can see the line and keep the perpendicular easier. Saw at this angle until you approach the lower limit, then tilt forward. The kerf keeps the saw straight now. Using a mirror avoids over cutting on the far side… 

That was using a crosscut saw, as I was cutting across the grain. I bought that saw a decade ago; I think it was a Victor. I’ve refiled the teeth a couple of times as I’ve been practicing saw sharpening. It cuts nicely, if not perfectly.

This saw… 

…is an old Disston saw I bought via ebay. It has had a few sharpenings over the years and is filed rip cut, for cutting along the grain. Note that the cut is started in the same way as the crosscut  but with the grain. Never this way… 

…which is against the grain. Same technique one employed for crosscutting; start with the heel of the saw low down and gradually tip forward until horizontal. I discovered a problem with this saw as I progressed in this deep cut. About 60% of the way through the cut it got tight and was more and more difficult to push. I suspect that the blade has become tapered the wrong way over the years. It should reduce in thickness from cutting edge to brass back. Unfortunately, I was down in patience that day so my response was to get more agressive with it. This was the result…. 

Close to the line on the near side but significantly off line on the far side. At least the error is on the waste side so is salvagable with a chisel.

To be continued…

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