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Posted: Sun Mar 17, 2013 6:16 pm
by dusty
I sure wish I lived in Sacramento. I'd bring a different blade over to your place and put an end to this mystery.

As for running without backup bearings - not practical. I said that without thinking. There is no way that the twist could be caused by those bearings, removing them would be more work than it is worth and it could result in the blade running off the back of the wheel as proper cant would cause that.

My bad.

Posted: Sun Mar 17, 2013 8:56 pm
by caleb
ok so I did as described I think.

I put my straight edge against the top and bottom edges of the lower wheel
and measured the distance the edge of the straight edge was away from the bottom and the top of the upper wheel.

the bottom edge was 1/8 away and the top was 3/32 away.

this was with the blade tensioned up.

without tension it is top edge
13/64
bottom edge 11/64

[ATTACH]20629[/ATTACH]

[ATTACH]20630[/ATTACH]

Posted: Sun Mar 17, 2013 9:31 pm
by JPG
Those measurements indicate insufficient cant and excessive bearing play.(assuming nothing else is moving).

It is late for me so I do hope that is a correct statement.

Posted: Sun Mar 17, 2013 9:39 pm
by caleb
I checked the movement in theupper arm with the wheel off and it was alkost nonexistant.

I will call ss I'm the morning to see if the will fix it.

Posted: Sun Mar 17, 2013 11:27 pm
by JPG
caleb wrote:I checked the movement in theupper arm with the wheel off and it was alkost nonexistant.

I will call ss I'm the morning to see if the will fix it.
They will likely want to sell you a new wheel.

Posted: Sun Mar 17, 2013 11:29 pm
by caleb
ok So I took the upper and lower blade guide bearings off and just left the auto blade guide.

and low and behold the blade doesn't twist. So I beleive that the cant is wrong
after doing this I noticed that the blade sits at the very backedge of the lower wheel.
and the top is the same

is cant = canter? That term has been confusing me a bit.
upper wheel
[ATTACH]20635[/ATTACH]
lower wheel
[ATTACH]20636[/ATTACH]


so during my conversations with SS tomorrow i will mention the blade twist and tell them all the steps we have been trouble shooting.

Thanks again for your help everyone I love this forum.

Caleb

Posted: Sun Mar 17, 2013 11:37 pm
by JPG
The wheel is canted. i.e. mounted at an angle. So we have been referring to that angle as cant(correctly or incorrectly).

After talking to CS, you might consider replacing the upper wheel bearing on this wheel. Relatively inexpensive to do so.

Those last two pix confirm my earlier thinking that the lack of upper wheel cant wants to force the blade too far towards the backside of the lower wheel than the lower guide bearing will allow.

Posted: Sun Mar 17, 2013 11:40 pm
by caleb
thanks I have in the past just pressed bearings in my self with a bearing vice. but alas in the USA I have no such tools could I do it with a normal bech vice and some flat angle?

Caleb

Posted: Sun Mar 17, 2013 11:46 pm
by JPG
caleb wrote:thanks I have in the past just pressed bearings in my self with a bearing vice. but alas in the USA I have no such tools could I do it with a normal bech vice and some flat angle?

Caleb
Pressing the old bearing out can be done with a little yankee ingenuity. Find a wrench socket that closely matches the od of the bearing, another that provides clearance for the 'exiting' bearing, and squeeze the triple stack with a vise.

Pressing new bearing only requires a vise(that will press straight).

Posted: Mon Mar 18, 2013 7:34 am
by dusty
caleb wrote:ok So I took the upper and lower blade guide bearings off and just left the auto blade guide.

and low and behold the blade doesn't twist. So I believe that the cant is wrong
after doing this I noticed that the blade sits at the very back edge of the lower wheel.
and the top is the same

is cant = canter? That term has been confusing me a bit.
upper wheel
[ATTACH]20635[/ATTACH]
lower wheel
[ATTACH]20636[/ATTACH]


so during my conversations with SS tomorrow i will mention the blade twist and tell them all the steps we have been trouble shooting.

Thanks again for your help everyone I love this forum.

Caleb

This entire thread has been very interesting and has caused me to think a lot about how the band saw really works to maintain proper tracking. I understand the function of the back up bearings. It is why(how) these guide bearings even come into play that has me puzzled.

Cant or canter. This seems to be the issue.

cant 1 (kImagent)n.1. Angular deviation from a vertical or horizontal plane or surface]2. [/B] A slanted or oblique surface.
3. a. A thrust or motion that tilts something.
b. The tilt caused by such a thrust or motion.

4. An outer corner, as of a building.

v. cant·ed, cant·ing, cants
v.tr.1. To set at an oblique angle; tilt.
2. To give a slanting edge to; bevel.
3. To change the direction of suddenly.

v.intr.1. To lean to one side; slant.
2. To take an oblique direction or course; swing around, as a ship.

OKAY.

So what? What is at an angle and to what reference?

Are the shafts of the two bandsaw wheels suppose to be parallel to one another or is this where the canter comes into play?

OR

Is the upper bandsaw wheel suppose to be canted with respect to the shaft? That does not seem likely (at least not to me). It seems to me that that would result in wobble.

Here is a sketch of what I think a canted upper bandsaw wheel is. However, ion this sketch the wheel is canted the WRONG way. The blade would tend to run right off the upper wheel.

[ATTACH]20639[/ATTACH]

Note that the two shafts are not parallel to one another. Is this the way it is done in the Shopsmith Bandsaw?

If so, would changing bearings fix anything for caleb????

I don't know. I am asking.