Bill ThompsonNM
01-13-2012, 12:51 AM
Last week I purchased an 11 year old Laguna LT18 Bandsaw ($800!), but a bandsaw with a problem. It fell over (with the previous owner) and landed on the motor, bending the lower frame of the bandsaw where the motor mounts. I looked at it carefully, watched it run and decided it was fixable. Basically the bend has added some vibration, but it still tracks excellent, etc.
So.I can use some advice as I work on it....
I've been working on it some this evening. I first made the assumption that the motor should be perpendicular to the sheet metal of the saw where the motor is mounted. Since my metal isn't very straight, I made it perpendicular to the metal surrounding the bearing for the lower wheel. I'm making the assumption that the motor is very symmetric so the fins should be parallel to the axis of the motor since I can't see how else to set it. Does this sound reasonable?
To get it perpendicular I have about a 1/4 inch shim at the top of the motor and used some 3/16 inch steel bar crossing over the hole for the motor on the backside to bolt the top of the motor to the frame with the shim between the motor mount and the frame.
Now, it appears I need to get the belt pulleys aligned directly one above the other. It's not clear what to use for a reference surface in this case. the pulley walls for the small motor pulley are a different thickness than the same wall on the drive pulley so I can't use a straight edge against the two pulleys.
I removed the blade and powered it up and all of this work has already made a significant improvement, maybe enough that if the pulleys were in good alignment I would be done.
I do realize that the extra bolts and shims, on the other hand will make changing and adjusting belts a royal pain.. since I'll pretty much have to repeat this procedure with any change.
I suspect I may want to make a large bolt on plate with similar mounting holes to fit over the frame mounting section, and then remove any damage material just around the motor mount where it sticks out one way or the other too much. Something like 1/4 inch steel or 0.3 inch aluminum. The aluminum would be easier to machine, but would have to be a little bit thicker for the same stiffness.
Suggestions?
and here's a picture of the saw. I have pictures of the mounting plate, but you can't really see the warped plate.. so not real useful.
So.I can use some advice as I work on it....
I've been working on it some this evening. I first made the assumption that the motor should be perpendicular to the sheet metal of the saw where the motor is mounted. Since my metal isn't very straight, I made it perpendicular to the metal surrounding the bearing for the lower wheel. I'm making the assumption that the motor is very symmetric so the fins should be parallel to the axis of the motor since I can't see how else to set it. Does this sound reasonable?
To get it perpendicular I have about a 1/4 inch shim at the top of the motor and used some 3/16 inch steel bar crossing over the hole for the motor on the backside to bolt the top of the motor to the frame with the shim between the motor mount and the frame.
Now, it appears I need to get the belt pulleys aligned directly one above the other. It's not clear what to use for a reference surface in this case. the pulley walls for the small motor pulley are a different thickness than the same wall on the drive pulley so I can't use a straight edge against the two pulleys.
I removed the blade and powered it up and all of this work has already made a significant improvement, maybe enough that if the pulleys were in good alignment I would be done.
I do realize that the extra bolts and shims, on the other hand will make changing and adjusting belts a royal pain.. since I'll pretty much have to repeat this procedure with any change.
I suspect I may want to make a large bolt on plate with similar mounting holes to fit over the frame mounting section, and then remove any damage material just around the motor mount where it sticks out one way or the other too much. Something like 1/4 inch steel or 0.3 inch aluminum. The aluminum would be easier to machine, but would have to be a little bit thicker for the same stiffness.
Suggestions?
and here's a picture of the saw. I have pictures of the mounting plate, but you can't really see the warped plate.. so not real useful.