Offseason gearbox project... maybe this gearbox has helical gears?

[Richard Wallace]

What's the diameter of the big gear?

[Travis Covington]

Originally Posted by Richard

What's the diameter of the big gear?

~ 5.25"

[Andrew Blair]

Supposedly, the box was engineered so as to create a gentle harmonic sound when ran, as versus the typical grindy noises. Are they really as smooth as reported? And will it make the Philharmonic?

[Pat Fairbank]

Originally Posted by Andrew Blair

Supposedly, the box was engineered so as to create a gentle harmonic sound when ran, as versus the typical grindy noises.

The sounds made by the two gear meshes in the box are supposed to be two octaves apart. Since two octaves would mean that the higher frequency is four times the lower one, I'm guessing all that means is that the medium-sized gear in the left side of the picture has four times as many teeth as the small gear beneath it, on the same shaft.

It's not really that big a deal engineering-wise, but the attention to detail is nice.

[Tristan Lall]

Originally Posted by Pat Fairbank

The sounds made by the two gear meshes in the box are supposed to be two octaves apart. Since two octaves would mean that the higher frequency is four times the lower one, I'm guessing all that means is that the medium-sized gear in the left side of the picture has four times as many teeth as the small gear beneath it, on the same shaft.

It's not really that big a deal engineering-wise, but the attention to detail is nice.

Here's the page detailling how the gearbox works.

[Richard Wallace]

Originally Posted by Richard

What's the diameter of the big gear?

The big gear has 91 teeth; 5.25" is too small for 16 DP and too big for 20 DP. Probably a metric gear, 1.5 module would be about right.