• The forum upgrades have been completed. These were moderate security fixes from our software vendor and it looks like everything is working well. If you see any problems please post in the Forum Technical Support forum or email us at forum_moderator (at) aawforum.org. Thank you
  • Congratulations to Bernie Hyrtzak, People's Choice in the January 2026 Turning Challenge (click here for details)
  • Congratulations to Matt Carvalho for "Red Mallee Folded Form" being selected as Turning of the Week for February 9, 2026 (click here for details)
  • AAW Symposium demonstrators announced - If the 2026 AAW International Woodturning Symposium is not on your calendar, now is the time to register. And there are discounts available if you sign up early, by Feb. 28. Early Bird pricing gives you the best rate for our 40th Anniversary Symposium in Raleigh, North Carolina, June 4–7, 2026. (There are discounts for AAW chapter members too) For more information vist the discussion thread here or the AAW registration page
  • Welcome new registering member. Your username must be your real First and Last name (for example: John Doe). "Screen names" and "handles" are not allowed and your registration will be deleted if you don't use your real name. Also, do not use all caps nor all lower case.

Stubby 750 or Robust , American Beauty

Sergio Villa said:
... Friction is what drive a belt pulley assembly even if too much friction becomes negative.
Click to expand...

Friction results in a lot of things -- all of which subtract from the available power at the spindle, but driving the belt pulley assembly is not what friction does. It is a necessary ingredient and any drive transmission whether belt, gear, or fluid has parasitic and induced frictional losses. A well designed system reduces friction to a minimum.

In your sketch, the closer spaced pulleys is always a more desirable condition than the ones spaced further apart. The power transfer is essentially the same in both cases, but the longer belt requires greater tension (which is bad because it shortens belt life) to avoid greater slippage than the shorter belt. Flutter and whipping is also a problem in longer belts that increases belt wear. Idler pulleys can be used to reduce those problems, but they bring along their own set of problems of increased friction and belt wear.
 
Bill Boehme said:
Friction results in a lot of things -- all of which subtract from the available power at the spindle, but driving the belt pulley assembly is not what friction does. It is a necessary ingredient and any drive transmission whether belt, gear, or fluid has parasitic and induced frictional losses. A well designed system reduces friction to a minimum.

In your sketch, the closer spaced pulleys is always a more desirable condition than the ones spaced further apart. The power transfer is essentially the same in both cases, but the longer belt requires greater tension (which is bad because it shortens belt life) to avoid greater slippage than the shorter belt. Flutter and whipping is also a problem in longer belts that increases belt wear. Idler pulleys can be used to reduce those problems, but they bring along their own set of problems of increased friction and belt wear.
Click to expand...

Even I can understand that.
 
You must log in or register to reply here.
Back
Top