Replies

1. 
   JohnWW | Jan 04, 2007 02:17am | #1

   The fault is probably with the blade, and typically won't effect the quality of your cuts too seriously.

   Unplug the machine and rotate the wheels by hand.  Watch the blade as it goes through the guides and note the section of the blade where the greatest movement occurs.  You may need to mark the blade with a felt tip marker to keep track of the section that is moving the furthest. 

   If the motion occurs repeatedly at the same spot on the blade, the blade isn't quite straight.  If the movement keeps appearing at different spots on the blade, then the fault is with the machine and will probably occur when the wheels are at the same position each time the most extreme movement occurs.

   If the fault is with the blade, it should disappear if you install a different blade on the saw.  Many blades are a bit crooked however, especially at the weld, so the replacement blade may also show some movement.

   If, after you've run this test, the fault appears to be with the wheels, e-mail me and I'll try to help you figure out the cause.

   John White 

2. 
   swing42 | Jan 04, 2007 06:03am | #2

   Hi John,

   Thank you for your response and the tests.

   I installed a new blade (same 1/2", 4 TPI) and rotated by hand. There is still about the same amount of movement.  The blade moves a lot in a couple of different places.  For each instance where it is extreme, the wheels are in the same alignment (a different set of coordinates for each place, but repeatable.)  This makes me think the machine is at fault. Do you agree?  What would you check next?

   Thanks,

   Mark

1. 
   JohnWW | Jan 06, 2007 12:24am | #3

   A bad blade is easy to diagnose and fix, a wobble from other sources is harder to pin down.

   Since you put new tires on the saw, I'd start with examining them.  It isn't likely that the wheels would suddenly be bent, or that the bearings have suddenly failed, unless the saw has been handled roughly while being moved or when doing repairs.

   Since it is a Delta saw, I presume that the tires are the type that just need to be stretched over the rim.  The new tires could possibly be defective, most likely uneven in thickness.  If you glued them on, which I don't recommend, a build up of glue under one area could cause an out of round condition that would affect the blades position. 

   The tires were probably quite hard to install and are often unevenly stretched.  Once the tires are on the rims, you should slip a 6" long, 1/2" diameter, dowel crosswise between the tire and the rim and work it around the rim's circumference a few times, which will lift the tire out of the groove and allow it to even out in tension.  After using the dowel, make sure the tire is sitting properly in its groove all the way around, it may need some additional pushing or prodding to get it fully seated between the raised edges of the rim.

   If the wobble isn't cured by reseating the tires you should next check whether the wheels are no longer flat.  The outside edges of the wheels are often unmachined, but the inside lip that retains the tire should run without a side to side wobble as the wheel is rotated. 

   To get an accurate sense of whether or not the wheels are out of flat, clamp a short length of wire to the wheel's sheet metal guard and bend the wire so it is close to the rim to give you a reference point as you rotate the wheel slowly by hand.  Run the test with a tensioned blade on the saw and see if the motion of the blade relates to the movement of the wheel's rim.  As before, if the fault is with the rim, the wobble should occur at the same spot or spots on the wheel's circumference each time you go through a complete revolution.

   If the wheel does seem to be wobbling, let me know and I'll try to help you to figure out why.

   John W. 

   Edited 1/5/2007 4:28 pm ET by JohnWW