flat belts don't you just love them. use them on conveyers at work make sure
you are getting at least 50% contact on pulley and you should not have any
slip, if using idler move away from the driving pulley. The more contact you
have on the driven pulley the better should stop the slipping
Troy L Gilbert

"John" wrote in message ...

wrote in message
oups.com...
Anyone here familliar with flat belt drives? I have an old-style floor
drill press that uses a flat belt to drive the pulley on the upper
cross shaft from the lower one and I want to put it back into running
condition. The belt has a tendency to slip under load and so I added an
adjustable idler near the lower driving pulley, on the side of the belt
that goes down as it is running, but now the belt wants to slip
sideways off the lower pulley when the idler is on. The belt tracks ok
when the idler is not in contact and I tried shimming first one side of
the idler shaft and then the other, thinking the alignement was off,
but this only seemed to make things worse. The idler shaft is paralell
to, and level with, the driving and driven shafts so far as I can tell.
Does it matter which side of the belt the idler is on? The original
belt was missing so I used one made from what looks like black rubber,
1 3/4" wide and 1/4" thick, and running at about 300 rpm. So maybe
rubber is not suitable for this application? Any advice appreciated.
Mike

Wow! Flat belt drives.....boy does that bring back some old memories. I
once worked (early 70's) at a farm machinery manufacturer in So. Idaho and
they had three machines (lathes) that were flat belt drive machines
(babbitt bearings too ). They had a main shaft, overhead drive unit that
ran all three machines. I don't remember exactly how it worked because I
tried to stay away from those machines as much as I could. Hmmmm, I
wonder if there are any shops that still use .......? No! Couldn't be!

John