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JPW? Blade and guides and bearing outer race face.mountainbreeze wrote:Mine sounds pretty much like yours. However, I also have the dreaded intermittent squeal that I have been unable to eliminate.
Is this a tried and proven solution or a "shot in the dark".JPG wrote:JPW? Blade and guides and bearing outer race face.mountainbreeze wrote:Mine sounds pretty much like yours. However, I also have the dreaded intermittent squeal that I have been unable to eliminate.
dusty wrote:Is this a tried and proven solution or a "shot in the dark".JPG wrote:JPW? Blade and guides and bearing outer race face.mountainbreeze wrote:Mine sounds pretty much like yours. However, I also have the dreaded intermittent squeal that I have been unable to eliminate.
) Then again it MIGHT help.The only deviation the SS band saw has is that it doesn't have an adjustable tracking mechanism to adjust the cant of the upper wheel. Since the cant is fixed and all blades track differently the SS band saw uses the auto track bearing on the left side to keep the blade from running off the back of the wheel. On non SS band saws the cant of the upper wheel is adjustable so the blade tracks properly without the need for the left side bearing. The same principle as the tracking adjustment on the 6" belt sander or the adjustable upper wheel on the strip sander.JPG wrote:Overthinking? I think not. This is a unique animal and requires rethinking to properly understand it's idiosyncracies.jsburger wrote:
This is all getting very confusing. I think this is another case of over thinking what is going on . The modern band saw has been around for well over 100 years virtually unchanged. But the SS deviates from that
The auto track roller bearing as SS calls it on the left side by the blade tensioner is a dual bearing. As such the back of the blade runs in the groove between the bearings and acts as a positioner and a backup since the SS upper wheel has a back cant. This bearing keeps the blade from running off the back of the wheel. My Powermatic 14" band saw has no such bearing on the left side since it presumably does not have a canted upper wheel. The bearing width is critical because the grove between the bearings has to be precisely on the tangent of the wheels.
Not only is the upper wheel canted, but both wheels are also beveled. The front lower bearing is indeed a guide for the blade positioning to the lower wheel.
The upper and lower backup bearings on the right side (business side) of the blade are single bearings. Their sole purpose is to to prevent the blade from being pushed off the wheels when you apply pressure to the blade during a cut. Their width is somewhat critical in that you want the back of the blade to ride on the center of the bearing. A few thousands one way or the other probably won't make much difference. If you apply side pressure to the work piece the blade will slid back an forth across the bearing and could be the source of some noise. LDH's dual bearing upgrade will minimize this.
Someone said the upper backup bearing should not touch the back of the blade when running free. Why?
BTW, when I first started cutting tenons on the band saw (bought new from SS)I found that the table was way out of square with the blade front to back. I used the shims in the help kit to get it right. There is nothing in my manual about squaring front to back.
That out of square is a result of all the canting and beveling. Shimming the table is the only way I know of to 'square the blade to the table'(front to rear)
If you have cool blocks and single backup bearings when you cut, the cool blocks will not keep the blade straight and the back will slide back and forth across the face of the backup bearing (albeit a small amount) and make noise. The Carter upgrade will not allow the blade to twist. If you do the LDH double backup bearing upgrade the back on the blade is further stabilized because it is running in the grove between the two bearings.
It took a long time to get to know it enough to understand it.
Yup, I said the same thing but JPG has proven what he said. There is a bevel though slight.jsburger wrote:The only deviation the SS band saw has is that it doesn't have an adjustable tracking mechanism to adjust the cant of the upper wheel. Since the cant is fixed and all blades track differently the SS band saw uses the auto track bearing on the left side to keep the blade from running off the back of the wheel. On non SS band saws the cant of the upper wheel is adjustable so the blade tracks properly without the need for the left side bearing. The same principle as the tracking adjustment on the 6" belt sander or the adjustable upper wheel on the strip sander.JPG wrote:Overthinking? I think not. This is a unique animal and requires rethinking to properly understand it's idiosyncracies.jsburger wrote:
This is all getting very confusing. I think this is another case of over thinking what is going on . The modern band saw has been around for well over 100 years virtually unchanged. But the SS deviates from that
The auto track roller bearing as SS calls it on the left side by the blade tensioner is a dual bearing. As such the back of the blade runs in the groove between the bearings and acts as a positioner and a backup since the SS upper wheel has a back cant. This bearing keeps the blade from running off the back of the wheel. My Powermatic 14" band saw has no such bearing on the left side since it presumably does not have a canted upper wheel. The bearing width is critical because the grove between the bearings has to be precisely on the tangent of the wheels.
Not only is the upper wheel canted, but both wheels are also beveled. The front lower bearing is indeed a guide for the blade positioning to the lower wheel.
The upper and lower backup bearings on the right side (business side) of the blade are single bearings. Their sole purpose is to to prevent the blade from being pushed off the wheels when you apply pressure to the blade during a cut. Their width is somewhat critical in that you want the back of the blade to ride on the center of the bearing. A few thousands one way or the other probably won't make much difference. If you apply side pressure to the work piece the blade will slid back an forth across the bearing and could be the source of some noise. LDH's dual bearing upgrade will minimize this.
Someone said the upper backup bearing should not touch the back of the blade when running free. Why?
BTW, when I first started cutting tenons on the band saw (bought new from SS)I found that the table was way out of square with the blade front to back. I used the shims in the help kit to get it right. There is nothing in my manual about squaring front to back.
That out of square is a result of all the canting and beveling. Shimming the table is the only way I know of to 'square the blade to the table'(front to rear)
If you have cool blocks and single backup bearings when you cut, the cool blocks will not keep the blade straight and the back will slide back and forth across the face of the backup bearing (albeit a small amount) and make noise. The Carter upgrade will not allow the blade to twist. If you do the LDH double backup bearing upgrade the back on the blade is further stabilized because it is running in the grove between the two bearings.
It took a long time to get to know it enough to understand it.
OK, since the lower bearing keeps the blade from running off the back of the lower wheel you can say it is used for positioning. By the same token the upper bearing does the same thing for the upper wheel.
I don't know what you mean by the wheels being beveled. I put a strait edge across the tires and both wheels are perfectly flat.
As for the upper backup bearing, how is just touching the back of the blade push the blade off the lower bearing?
This is odd. It appears that 627Z bearings come in at least two different sizes; I have 7x22x7 and JPG has 7x22x10. I have located 7x22x10 bearings at VXB. The description is LR50/7NPPU Track Roller 2 Rows Sealed. I have yet to receive these so I suggest that you not buy until it can be verified that they work. They are a bit more (2x) expensive that the bearings from Shopsmith.JPG wrote:dusty wrote:You and I are using slightly different terminology.
. . .
When you, JPG, speak of the original rear guide bearing - to which bearing do you refer.
BTW, right now I have a pair of 627ZZ bearings in the auto-track position and one each 627ZZ in each of the back up bearing positions. I have not done any extensive testing yet but I am seeing no reason why the two back up bearings need to be 10mm wide. Cutting a few curves may show me why!!
The 'lower' "backup" bearing is actually a guide/positioner for the blade as it nears the lower wheel just like the rear/upper bearing(s) with the upper wheel. So it performs a dual function.
I am measuring a 627 bearing to be 10.25 mm wide.
The 'original' upper rear guide bearing was a single bearing. I cannot say for sure the size, but SS historically would use the same bearing for all three locations so as to minimize 'different' parts.
OK, I misunderstood what bevel meant in this case.dusty wrote:Yup, I said the same thing but JPG has proven what he said. There is a bevel though slight.JPG wrote:The only deviation the SS band saw has is that it doesn't have an adjustable tracking mechanism to adjust the cant of the upper wheel. Since the cant is fixed and all blades track differently the SS band saw uses the auto track bearing on the left side to keep the blade from running off the back of the wheel. On non SS band saws the cant of the upper wheel is adjustable so the blade tracks properly without the need for the left side bearing. The same principle as the tracking adjustment on the 6" belt sander or the adjustable upper wheel on the strip sander.jsburger wrote:
Overthinking? I think not. This is a unique animal and requires rethinking to properly understand it's idiosyncracies.
It took a long time to get to know it enough to understand it.
OK, since the lower bearing keeps the blade from running off the back of the lower wheel you can say it is used for positioning. By the same token the upper bearing does the same thing for the upper wheel.
I don't know what you mean by the wheels being beveled. I put a strait edge across the tires and both wheels are perfectly flat.
As for the upper backup bearing, how is just touching the back of the blade push the blade off the lower bearing?
http://www.shopsmith.com/ss_forum/viewt ... el#p180012
However in the SS case positioning is an absolute requirement. Without it it WILL slip off the back.Yes I did think it through and that is exactly what I was thinking. I just didn't explain what I was thinking in the same way. I knew what I was thinking why didn't you?JPG wrote:Think it through completely.
The blade has to remain in a flat plane. At least the back edge of it. The rest of the blade is 'normal' to that plane.
Now with a canted upper wheel, the tires must be beveled at an angle half of the cant angle. The bevel on the tires brings the blade to that flat canted plane. That places that flat plane at an angle half the cant angle.
Other bandsaws have crowned wheels and the adjustable upper wheel cant provides a method to manually set tracking(indeed similar to the belt sander).
Usually that manual setting must be performed when changing blade widths etc. The SS design eliminates the need for that. It also eliminates the need to readjust the blade backups between blade changes.
Yes both upper rear and lower front guide bearings prevent the blade sliding off the back of the wheel. It does that by positioning the blade as it approaches the wheel. i.e. positioning/preventing = same thing!
