During our Open House yesterday, the belt on our older SP-15 slipped off the motor pulley. After the gig, we opened up the top and put the belt back on, but it looks like it may easily slip off again. This press has geared wheels at the motor and the drum roller, and the rubber belt has teeth in it (the other press has a v-shaped pulley system). The belt is smaller in width than the gear wheels. One side of the motor wheel has a guard that looks like it’s supposed to keep the belt from slipping off. But the guard is missing on the side closest to the motor. Should there be a guard there? Any other solutions to keep the belt in place? Will try to publish pics later today.
If the belt is loose you need to shift the motor until it is tight. These belts will strip easy if not correctly in place. Fortunately you can buy them from Grainger. They are not expensive.
From the photo, it looks like the drive pulley could be shifted to the left to align with the belt. Perhaps the setscrew loosened up and moved or vibration got to the pulley over time. Can you retract the setscrew and tap the drive pulley over? It looks like there isn’t much room to work, but you might be able to use a pry bar (gently) to move it back in place.
Here are additional pics.
Thanks, John. I have attached some photos. I think you are on target: it looks like the two pulleys are not aligned. (Can’t get into the space to use the straightedge trick…) The motor mount will not allow movement side to side (ie, operator side to non-operator side). The motor pulley seems to be held in place with a pin and set screw. Can this be adjusted? Note also that the cylinder on this press has some side to side play, about 1/8″. It is missing a set screw on the non-operator side (see photo). It’s always been that way and this is the first time we’ve had this problem, so I’m not sure if that is related.
Photos would be helpful, but the primary method of keeping such a belt in place is alignment of the two pulleys. Perhaps one of the mounts has slipped and the alignment has been lost. If the two pulleys are of equal thickness, you might be able to lay a straightedge along the flat side surface of both and see if the straightedge lays flat against the sides of both. If not, adjust the motor mount or move the pulley on either shaft so that the faces are in line with each other.
I don’t have any pictures to aid in this description, but ask more questions if need be to get the problem resolved.
Tension can also be the culprit, but it is more than likely alignment.