Model Boat Mayhem - Forum

Please login or register.

Login with username, password and session length.
Pages: [1]   Go Down

Author Topic: Lead bulb  (Read 875 times)

dreadnought72

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,865
  • Wood butcher with ten thumbs
  • Location: Airdrie, Scotland
Lead bulb
« on: September 10, 2010, 06:51:40 PM »

Hi there,

I hope this is useful to anyone.

THIS IS A LINK to a lead bulb in .png format, HERE'S THE SAME ONE as a .jpg. The centre of gravity is shown. Right-click and "save as" if you fancy a copy.

It's an accurate form for the Eppler 520, scaled here to be about 133% fatter than the airfoil, and the images are at 300 dpi. (They'll look too big on a screen set to a 72dpi or 96dpi resolution, but if printed at 300dpi it'll be correct - about 28cms long and around 6cm in diameter.)

If cast in lead, it'll mass 9.5 lbs or ~4310 grammes.

You can scale it up or down, if need be. Scaling will change the volume, and therefore the mass. For example:

Scale all dimensions => 120% = 1.2 times all linear dimensions = 1.2^3 = 1.728 times the volume and mass

If you change the width, you'll change the cross-sectional area and therefore the mass. For example:

Scale the width => 80% = 0.8 times the width dimensions = 0.8^2 = 0.64 times the volume and mass

The centre of gravity won't change with scale, of course.

Andy
Logged
Enjoying every minute sailing W9465 Mertensia
Pages: [1]   Go Up