I replaced the flat belt on my lathe with a timing belt turned inside
out. While it's much better than the old, dried up, cracked leather
one, it still seems to slip too much. Since I don't want to over
tighten it, how can I tell how tight is right?

It seems that for a given size motor, you should be able to get a
certain cut for a given material and you could tighten the belt until
that happened. E.g., a 1/3 hp motor should be able to a take a x deep
cut, at y feed, at z rpm in d dia 1018. If the belt slips for this set
up, it's too loose.

Or, can I just use the old 1/2" (?) deflection rule? Does that apply to
inside-out timing belts?

Thanks.
Bob

On Sat, 08 Jan 2005 19:28:40 -0500, Bob Engelhardt wrote:

I replaced the flat belt on my lathe with a timing belt turned inside out.
While it's much better than the old, dried up, cracked leather one, it
still seems to slip too much. Since I don't want to over tighten it, how
can I tell how tight is right?

I don't know what your belt looks like, but the ones I've seen have
too rough a surface to make a good flat drive belt. But with their
internal cords they'll quite a bit of tension. So I'd say to to just
tighten the belt a bit more. At the worst the belt just won't last a long
time. A little slippage when taking heavy cuts is going to tend to wear
the belt a bit smoother and ultimately cause it to slip less.

Why not get a made up leather belt or belt stock and make up a real belt
with a skived joint and hide glue?
--
The instructions said to use Windows 98 or better, so I installed RedHat.

BOB
A better choice from the auto parts store is a regular micro-v belt.
You can get some pretty wide ones. Use it turned normally, with the
grooves toward the pulley. The backside of those belts are for tensile
strength, not grip.

Bob Engelhardt wrote:
I replaced the flat belt on my lathe with a timing belt turned inside
out. While it's much better than the old, dried up, cracked leather
one, it still seems to slip too much. Since I don't want to over
tighten it, how can I tell how tight is right?

It seems that for a given size motor, you should be able to get a
certain cut for a given material and you could tighten the belt until
that happened. E.g., a 1/3 hp motor should be able to a take a x deep
cut, at y feed, at z rpm in d dia 1018. If the belt slips for this set
up, it's too loose.

Or, can I just use the old 1/2" (?) deflection rule? Does that apply to
inside-out timing belts?

Thanks.
Bob

A little belt dressing (Bee's Wax or Pine Tar) Will help give
additional grip. You can still get flat belt components from
McMaster-Carr online also.