13-05-2016, 02:29 PM
(13-05-2016, 10:58 AM)Mark Hennessy Wrote: Just to add, the video you can see at the bottom of that page demonstrates this perfectly (don't recall watching this before). Towards the end, he runs up a bandsaw, which has a tilt adjustment on the top pulley, and shows how the belt can be moved from the centre of the crown.
On large bandsaws the bandsaw blade doesn't always run dead center on the top crown wheel, it's offset to the left so that the bottom of the gullet overhangs the the top crown wheel by about 3 mm, if it doesn't the bands will start to crack at the gullet, once that starts and left running then the gullets either side of the first one will start to crack and on it goes, if left unchecked then eventually the original first crack in the first gullet will spread right across the bandsaw blade and will ultimately fail...catastrophic/deadly if any sawdust is packed tight between the bottom of the band on the bottom band wheel and the floor or base of the saw 'cos the band can shoot out like a snake.
With belt drive and crowned pulley, worn shaft bearings/shafts out of parallel can cause the belt to wander off.
Lawrence.
