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Bandsaw blades keep falling off -HELP ME PLEASE!
Posted: Sat Jan 29, 2011 4:06 pm
by forrestdeer
I picked up my Shopsmith a while back, just now getting it up and running..
Here's my problem, At 700 RPM I turn on the bandsaw and after a few seconds
the blades flies off.
After turning off/unplugging, I replace the blade and try again.. Again the blade falls off.
Same routine, this time with a different/larger blade and again the blade falls off.
Now needless to say this is scary, and replacing bent/broken blades will get expensive. I've replaced dozens of blades blades on other bandsaws and never had a blade fly off. But this happens over and over again, obviously I don't know what I'm doing.
I have all the Shopsmith manuals for all of my tools -EXCEPT the bandsaw!!
I cant figure out why this is happening, I really need to get this working.
Any ideas or suggestions greatly appreciated.
-Forrest
Band saw blade keeps falling off
Posted: Sat Jan 29, 2011 4:43 pm
by dusty
Yes, Forrest, I do have a suggestion. Put the blade saw blade back on and then DO NOT turn it on.
While turning the wheel by hand, watch to see how the blade tracks on the upper wheel. It should tend to center itself just to the rear of the center line on the upper wheel. Check
this post for general instructions.
A couple pictures
here for visual reinforcement.
To fix this, I recommend that you try this:
With power cord unplugged and the switch turned off,
grasp the upper wheel with both hands (the left hand bottom/center and the right hand top/center),
in a jerking motion, pull the bottom to you while simultaneously pushing the top away. One good jerk should be enough.
This should position the upper wheel so the the bottom is slightly forward of the top.
Now spin the wheel by hand and watch how the blade tracks.
Posted: Sat Jan 29, 2011 5:42 pm
by forrestdeer
Thanks for the help!
I checked out the wheel alignment, from everything I've read, It appears to be OK. Then I replaced the blade, spun the wheel several hundred times by hand and blade seemed to follow the guide bearings well with no travel or drift.
So I turn the machine on for a couple of seconds at a time, each time a little longer than the last. Realizing I was never allowing the machine to fully speed up, I decided to just let it run.. This time the tire comes off, leaving the blade on the wheel.
Was it a tire problem all along? It seems you can't just purchase a tire, you need to buy a new wheel/tire as a set? Is this the case?
Thanks in advance!
Posted: Sat Jan 29, 2011 5:58 pm
by dusty
forrestdeer wrote:Thanks for the help!
I checked out the wheel alignment, from everything I've read, It appears to be OK. Then I replaced the blade, spun the wheel several hundred times by hand and blade seemed to follow the guide bearings well with no travel or drift.
So I turn the machine on for a couple of seconds at a time, each time a little longer than the last. Realizing I was never allowing the machine to fully speed up, I decided to just let it run.. This time the tire comes off, leaving the blade on the wheel.
Was it a tire problem all along? It seems you can't just purchase a tire, you need to buy a new wheel/tire as a set? Is this the case?
Thanks in advance!
No, that is not the case. You can purchase tires without buying wheels.
The new urethane tires are part number 522458 ($31.58), Urethane Bandsaw Tires. I have no experience changing tires but several forum members have done so successfully.
Posted: Sat Jan 29, 2011 6:16 pm
by SDSSmith
forrestdeer wrote:Thanks for the help!
I checked out the wheel alignment, from everything I've read, It appears to be OK. Then I replaced the blade, spun the wheel several hundred times by hand and blade seemed to follow the guide bearings well with no travel or drift.
So I turn the machine on for a couple of seconds at a time, each time a little longer than the last. Realizing I was never allowing the machine to fully speed up, I decided to just let it run.. This time the tire comes off, leaving the blade on the wheel.
Was it a tire problem all along? It seems you can't just purchase a tire, you need to buy a new wheel/tire as a set? Is this the case?
Thanks in advance!
In addtion to the urethane tires Dusty noted, you can also get the regular black rubber tires. Part 555644 is a single tire with adhesive and part 518108 is just the plain tire. You would need one of each if you want to replace both of your tires (one tube of adhesive is enough for both tires). The cost is about the same as the urethane tires if purchased from Shopsmith. You can usually get a little better deal on urethane tires from Ebay seller ohioblademan (not only on price but on shipping cost). Here is one of his auctions for urethane tires. You will find that replacing the tires with the urethane tires is simpler (no glue) than with the rubber tires.
Bandsaw Blades keep falling off.
Posted: Sun Jan 30, 2011 10:09 am
by dusty
It has been said that a bent wheel can cause this problem. I went to the shop this morning to contemplate that statement. Maybe yes, so I took a look to see if I could find a way to ascertain whether or not a blade is bent.
I used a combination square - sitting on the table with the blade just touching the wheel. If the wheel is bent when it spins the alignment (or mis-alignment) with the wheel become obvious.
Hopefully
this will help to determine the cause of your problem.
Posted: Sun Jan 30, 2011 1:15 pm
by JPG
forrestdeer wrote:Thanks for the help!
I checked out the wheel alignment, from everything I've read, It appears to be OK. Then I replaced the blade, spun the wheel several hundred times by hand and blade seemed to follow the guide bearings well with no travel or drift.
So I turn the machine on for a couple of seconds at a time, each time a little longer than the last. Realizing I was never allowing the machine to fully speed up, I decided to just let it run.. This time the tire comes off, leaving the blade on the wheel.
Was it a tire problem all along? It seems you can't just purchase a tire, you need to buy a new wheel/tire as a set? Is this the case?
Thanks in advance!
If you do not have a ss bandsaw manual or reading material specific to the ss bandsaw, then what you have been reading has probably mislead you. Your experience with other bandsaws is also possibly misdirecting you. If you checked the wheels and they WERE COPLANER, then THAT will cause the blade shedding 'issue'.
Sorry to be so blunt, but yer attention is needed! This animal is different!!!
The ss upper wheel is tapered, not crowned like the rest of the bandsaw world. The wheel is also canted(top in bottom out)[that is what Dusty's instruction was all about]. The bearing shaft bar can get fatigued and cause the cant to diminish.[also caused by constant tension].
Have you adjusted the blade tension(red bar spring indicates proper tension). Adjustment is accessible from the back.
Speaking of tension, it should be released(loose blade) when not in use to prevent the fatigue mentioned above.
Back to the upper wheel - Being tapered and canted. the blade will tend to slip off the inside of the wheel. There are two bearings located in the upper left that the back of the blade rides against(They be called blade guides[not to be confused with the ones 'down below'])
Now as for the tire - what color is it(red orange or black?) Black is glued on rubber, red is 'shrink fit'(actually you stretch it to 'get it on').
A straight edge placed against the upper wheel(top to bottom) should extend and stick out from the lower tire slightly(NOT coplaner!!!!!)
Posted: Sun Jan 30, 2011 1:27 pm
by JPG
dusty wrote:It has been said that a bent wheel can cause this problem. I went to the shop this morning to contemplate that statement. Maybe yes, so I took a look to see if I could find a way to ascertain whether or not a blade is bent.
I used a combination square - sitting on the table with the blade just touching the wheel. If the wheel is bent when it spins the alignment (or mis-alignment) with the wheel become obvious.
Hopefully
this will help to determine the cause of your problem.
"THIS" Is Excellent Dusty!!!!!!!!
A side view of the 'square' is the ONLY thing I would suggest as an improvement!(for future reference only) That is also where any wobble could be observed.
Damn! If this is a fledgling attempt, what is to come will be worth waiting for.
Kudos for going slow enough for the observer to keep up! Gives us ADHD types time to ponder all that 'other' stuff floating in our 'head'.
P.S. I
also think the 'noise' in the 'other' video is Power Station, not Bandsaw. Have you tried bs mounted on ss instead?
Posted: Sun Jan 30, 2011 1:34 pm
by pennview
Just a couple of thoughts on why the blades and then the tire would come off the wheel(s).
Did you have too much tension on the blade? If it isn't a s Shopsmith blade, it could be a bit shorter than 72" (the length of a Shopsmith blade) and then using the tensioning gauge settings would put too much tension or stress on the saw.
Or, are you running the saw at too high a speed? Since you're new to the Shopsmith, perhaps the speed dial isn't set properly, resulting in the saw running faster than you think. With the dial reading "slow," the belt should be at the bottom or deep into the lower sheave (the sheave attached to the motor). You'll have to remove the belt cover to check this. When set properly, the dial should stop turning at both the "slow" and "high" marks on the dial. Of course you must have the motor running when you turn the dial.
Posted: Sun Jan 30, 2011 1:48 pm
by dusty
JPG40504 wrote:"THIS" Is Excellent Dusty!!!!!!!!
A side view of the 'square' is the ONLY thing I would suggest as an improvement!(for future reference only) That is also where any wobble could be observed.
Damn! If this is a fledgling attempt, what is to come will be worth waiting for.
Kudos for going slow enough for the observer to keep up! Gives us ADHD types time to ponder all that 'other' stuff floating in our 'head'.
P.S. I also think the 'noise' in the 'other' video is Power Station, not Bandsaw. Have you tried bs mounted on ss instead?
Yes, there certainly should have been a side view of the combination square showing the contact point of the square to the wheel.
Yes, I have tried the bandsaw on a Mark V as well as on the other Power Station. Findings: The Power Station and the Bandsaw (shown in the video clip) need some work. When running the Bandsaw on the Mark V, it is still noisy but was not as bad on the other Power Station.
Bottom line - both my stand-bye bandsaw and my 2nd Power Station are quieter than the ones I have been using every day. There is work to be done.