Bandsaw - new blade won't stay on

[jms]

I purchased a 520 back in January, came with a decent 1/4" blade on the bandsaw that runs, spins, and cuts just fine.

I'm milling down some laminated poplar into 4"x4" table legs and so I bought the 1/2" blade from SS (521987 - premium woodcutting blade) to resaw the leg blanks.

The problem is I cannot get the 1/2" blade to stay on the saw. It very quickly moves to the front (towards the teeth) and off the wheels, every time. I have adjusted the bandsaw tension scale per the manual to no avail, and it is on there pretty dang tight. The blade sits in close proximation to all of the bearings when I first install it, but quickly moves away.

Now, when I re-install the 1/4" blade, it again sits right where it's supposed to and runs, spins, and cuts just fine.

Any pointers ??

[JPG]

Please describe where the 1/4" blade 'sits as it is supposed to'.

I hope that includes the back of the blade runs tight against the rear and lower front guide bearings.

And that the back of the blade runs about 1/4" from the back of the rim of the upper wheel.

[jbooher]

Several years ago I had a blade that would not stay on. Put several blades on the bandsaw since with no problems. Check with Shopsmith About a blade replacement.

[jms]

JPG -- yes the 1/4" blade runs tight against the rear and lower bearings, and sits about 1/4" from the back of the upper wheel rim.

I also have an almost new 1/2" woodslicer blade from Highland that has a kink in it - thats why I ordered the 1/2" SS blade to begin with -- and the WoodSlicer rides with no issues in very similar fashion to the 1/4" blade.

The SS 1/2" blade runs off the wheel in about 10 revolutions every time, starting it in the same place.

jbooher -- I will call SS customer service, they have been great replacing other malfunctioning new parts.

[JPG]

With the tension set for a 1/4" blade, does the new ss 1/2" blade still slip off?

I be getting suspicious of a bad bearing in the upper wheel or a weak support arm.

[jms]

With the tension set for a 1/4" blade, does the new ss 1/2" blade still slip off?

I be getting suspicious of a bad bearing in the upper wheel or a weak support arm.

Tried this, yes it still slips off. There is no noticeable movement in the wheel bearing or support arm, everything appears to be sturdy.

Now, there is an indentation in the shape of the 1/4" blade in the tires but it doesn't seem to affect the WoodSlicer blade so I'm not sure if that is relevant.

I do have a set of SS urethane tires but after reading the forums posts on changing over from the rubber tires, I'm not sure I want to start that job just yet :-)

[charlese]

It appears to me that your 1/4" blade was left on the saw for a long time while under a tightened state. Hence, the 1/4" groove in the tires. This was also the case with my new bandsaw.

The problem created by this prolonged tension was not the groove, but the stressed and twisted condition of the upper bearing arm. You can re-set the proper setting of arm by manually twisting the arm upward.

Here's your check to see if this is the case:
If you lay a straight edge across the rims of the upper wheel, the straight edge should come almost 1/4" in front of the lower wheel.

There are at least two methods to accomplish this "re-bending".
1) Grab the upper wheel with one hand at the top and the other at the bottom. Firmly pull the lower hand while pushing the upper hand.
2) Remove the upper wheel and slip a pipe onto the bearing seat. Twist the arm by raising the pipe.

[JPG]

It appears to me that your 1/4" blade was left on the saw for a long time while under a tightened state. Hence, the 1/4" groove in the tires. This was also the case with my new bandsaw.

The problem created by this prolonged tension was not the groove, but the stressed and twisted condition of the upper bearing arm. You can re-set the proper setting of arm by manually twisting the arm upward.

Here's your check to see if this is the case:
If you lay a straight edge across the rims of the upper wheel, the straight edge should come almost 1/4" in front of the lower wheel.

There are at least two methods to accomplish this "re-bending".
1) Grab the upper wheel with one hand at the top and the other at the bottom. Firmly pull the lower hand while pushing the upper hand.
2) Remove the upper wheel and slip a pipe onto the bearing seat. Twist the arm by raising the pipe.

That is 'our' former consensus until 'we' acquired the 1/4" from the rim detail from CS.

I think both are valid, but the 1/4" is a more direct determination.

Do the straight edge check, but, with the recalcitrant blade mounted and tensioned and aligned to the guide bearings.

The purpose is to eliminate changing cant as the cause.

I think if you have a 1/4" groove of substantial depth 'worn' into the tires, that the wider blade will have greater tension on the tooth edge that is causing the blade to slide towards the front.

Is it possible that the worn 1/2" blade that behaves, has less tooth set?

[jms]

So -- my straightedge, when laid flat across the rim of the top wheel (touching it in 2 places) - ends up lying about 1/4" "behind" the bottom wheel - meaning with my straightedge in this position it "touches" the bottom wheel as seen in this photo ...

[trainguytom]

Did you lay the blade flat on a bench or table, teeth facing up, to see if it's true?