Jet 14" bandsaw problems.

[larryc]

I noticed that the blade on my bandsaw was rubbing on the right side of the insert.
I took the table off and backed off the guides and rollers and with the blade tensioned, the photos show what is occurring.
The measurement between the blade and the left side of the lower guide block holder is 11/32" compared to 13/64" between the blade and the right side of the holder. About two to one rather than equal distance.
I've checked that the wheels are coplaner but I'm at loss to figure what is causing this problem.
I don't see any way to adjust the lower guide block holder.
This seems to be a problem that has occurred recently and I don't know what caused it or how to cure it.
Any suggestions?

Somehow the right hand photo got flipped on its side when attached and I don't know how to fix that.

 

[jttheclockman]

Larry, usually what is done on top with the blade guides is exactly what is done with the lower guides. Allen screws to hold the guide blocks in place. You need to loosen them and set them against the blade. The old adage is the thickness of a dollar bill away from the blade. The blade guides are pushed forward to about a 1 /32" from the gullet on the teeth. The thrust bearing just hits the back of the blade when the blade is trued on the wheels (centered of the wheel)

There are a ton of videos on utube showing how to tune any saw. Just google your saw for instructions. If you have the instruction booklet it will show you how to tune it also.

 

[larryc]

Larry, usually what is done on top with the blade guides is exactly what is done with the lower guides. Allen screws to hold the guide blocks in place. You need to loosen them and set them against the blade. The old adage is the thickness of a dollar bill away from the blade. The blade guides are pushed forward to about a 1 /32" from the gullet on the teeth. The thrust bearing just hits the back of the blade when the blade is trued on the wheels (centered of the wheel)

There are a ton of videos on utube showing how to tune any saw. Just google your saw for instructions. If you have the instruction booklet it will show you how to tune it also.

I know how to adjust the guides. That is not the problem.
Maybe I didn't explain it properly.
With both the top and bottom guides completely retracted away from the blade, the blade is too far to the right.
Adjusting the guides will not solve this problem because as you pointed out the guides should not touch the blade.

 

[jttheclockman]

Was it always that way and you never noticed??? Did you change blades or make of blades. Larger blades do not flex as much as smaller thinner blades. Not all blades are made from the same metal content. If you put more tension on the blade does it move closer to center?? Not all blades tension the same even though they are the same size. Metal content maybe different. That is why there is adjustments on those carriages.

 

[larryc]

Was it always that way and you never noticed??? Did you change blades or make of blades. Larger blades do not flex as much as smaller thinner blades. Not all blades are made from the same metal content. If you put more tension on the blade does it move closer to center?? Not all blades tension the same even though they are the same size. Metal content maybe different. That is why there is adjustments on those carriages.

No the blade has not been changed. This is a condition that seems to have happened recently. I first noticed it when the blade started to rub on the insert. Good thought on the blade tension but that doesn't seem to affect it either.

 

[Lenny]

I assume you have rotated the wheels by hand to make sure it's not a kink in the blade causing the problem?
Just for the heck of it, take all the tension off the blade, completely remove the blade and perhaps even try another one. Perhaps something is catching on the guide post or upper wheel, throwing everything off.

 

[larryc]

I assume you have rotated the wheels by hand to make sure it's not a kink in the blade causing the problem?
Just for the heck of it, take all the tension off the blade, completely remove the blade and perhaps even try another one. Perhaps something is catching on the guide post or upper wheel, throwing everything off.

Been there - done that.

 

[Lenny]

On our 14" Delta at work (or maybe it was my Jet at home ... it's awful to get old and forgetful) I had an issue similar. If I remember correctly the upper wheel or tensioning bracket was fetching up when tension was applied, not sliding up the way it should. Forgive me if that isn't clear, it's a fuzzy memory, but loosening everything up, lubricating and changing the blade (even if you use the same blade) would be a good place to start.

 

[jttheclockman]

Larry do you have a riser block on that saw??? Did it get loose and shift. It would throw the two wheels out of alignment. Take the tension off and is there play in the bearings as you move the wheels side to side. Not sure that this is a problem that can not be lived with. Outside of the clearance plate is it rubbing on anything. You should see the clearance plate on my saw.

 

[larryc]

Larry do you have a riser block on that saw??? Did it get loose and shift. It would throw the two wheels out of alignment. Take the tension off and is there play in the bearings as you move the wheels side to side. Not sure that this is a problem that can not be lived with. Outside of the clearance plate is it rubbing on anything. You should see the clearance plate on my saw.

Great minds think alike!

I thought about that this morning and checked the riser block. I had forgotten, since I installed it several years ago, that it has pins to prevent it from shifting.

And I am beginning to think that replacing the clearance plate with a zero clearance plate from Iturra and just live with it.

 

[larryc]

On our 14" Delta at work (or maybe it was my Jet at home ... it's awful to get old and forgetful) I had an issue similar. If I remember correctly the upper wheel or tensioning bracket was fetching up when tension was applied, not sliding up the way it should. Forgive me if that isn't clear, it's a fuzzy memory, but loosening everything up, lubricating and changing the blade (even if you use the same blade) would be a good place to start.

Been there, done that even with a different blade.

 

[jttheclockman]

Larry do you have a riser block on that saw??? Did it get loose and shift. It would throw the two wheels out of alignment. Take the tension off and is there play in the bearings as you move the wheels side to side. Not sure that this is a problem that can not be lived with. Outside of the clearance plate is it rubbing on anything. You should see the clearance plate on my saw.

Great minds think alike!

I thought about that this morning and checked the riser block. I had forgotten, since I installed it several years ago, that it has pins to prevent it from shifting.

And I am beginning to think that replacing the clearance plate with a zero clearance plate from Iturra and just live with it.

If you do not have any added vibrations or tracking problems, the blade goes in a circle so be it. The only thing it may effect is any jigs you have made referenced to the old tracking path.

For me when I need a zero clearance plate on the bandsaw I use masking tape. I do a lot of free style cutting which require twisting and turning and the blade is always moving some. Just the nature of the saw.

Maybe some one else has seen this before and has a solution but I am out. Good luck.

 

[Gary Beasley]

What condition are the tires in? If they are beat down it may well throw the blade out of line like that.

 

[larryc]

Talked to Louis at Iturra Design today and he is as perplexed as everyone else. I already had a new blade and tires on order so we will see if that makes any difference.

 

[larryc]

I am having this same problem except the blade is riding so far to the right that it barely touches the upper thrust bearing and completely misses the lower thrust bearing.
This seems to have happened suddenly as I had been cutting some dogwood burl.
I have replaced the tires, blade and thrust bearings and no improvement.
It is not the table because the thrust bearings are completely independent of the table.
Louis of Iturra Design (the bandsaw experts) has no ideas for me.
Anybody on the forum have any ideas?

I posted this on another forum and copied and pasted it here to see if anyone has any new ideas.

 

[jttheclockman]

Larry

Why don't you post a few photos of the saw itself. Both with the doors opened so we can see the blade tracking.(full length) Also a photo of the underside of the table. Also take a photo of the back of the saw where the blade gets tensioned. Also give us the number of the saw. How old is the saw??? Does the saw make any unusual noises or noises that have just started recently and if so where are they coming from??? I bet this is something you are overlooking and is a simple fix. With a bandsaw it is one of the most basic machines out there. Blade goes around a wheel. We will get to the bottom of this.

 

[larryc]

Larry

Why don't you post a few photos of the saw itself. Both with the doors opened so we can see the blade tracking.(full length) Also a photo of the underside of the table. Also take a photo of the back of the saw where the blade gets tensioned. Also give us the number of the saw. How old is the saw??? Does the saw make any unusual noises or noises that have just started recently and if so where are they coming from??? I bet this is something you are overlooking and is a simple fix. With a bandsaw it is one of the most basic machines out there. Blade goes around a wheel. We will get to the bottom of this.

Attached are some photos with the table removed.
The blade is tensioned.
The saw is a Delta 28-276 about 5 years old.
No unusual noises.

 

[jttheclockman]

Hello Larry

Thanks for posting the photos. Even though it is a newer saw it basically is the same saw that I have except yours has the quick tension lever. Lets say we break this down into the most basic way we can. What I am going to suggest is a couple things and in no ways is foolproof or may even may not make sense. But i do not see anyone else offering any advice.

Now we know the trunnions are mounted to the frame and unless there are bolts loose then this has not moved. Same on upper and lower. You never had a problem before recently. First question have you done anything differently???? If no then we move on. How do you tension your blade???? Can you tension the blade without using the quick tension lever??? I believe you can. Here is my point or points. Something is throwing the blade off its center axis. Those wheels should be dead center of each other.

First thing is level the bottom frame that the saw sits on, left to right. Now tension the blade with the hand wheel and not the tension bar. Place a level on the blade(backside away from the pitch of the teeth) and the blade should be dead level. If it is that is good. While doing this watch the blade up against the back thrust bearing. (by the way release all blade guides and thrust bearings so nothing is touching the blade. ) That back thrust bearing does not move side to side and is stationary so it is a fixed point. If the blade is sitting against that bearing where it should be that is good. Now release the tension on the blade and again tension the blade using the quick tension bar. Again watch the blade and check if there is any movement side to side on the blade as you tension it. The blade should again be dead level. If it moves with the bar then there is something wrong with that tensioning system and start looking there. There was a recall years ago about the tensioning system on the Delta and all knockoffs of that saw about 10 years ago. That is why I asked how old it was.

Now if all that fails and everything works the way it is suppose to then we have to look elsewhere.

We have to find out for sure those wheels are lined up dead center of each other. We also need to make sure that any bolts holding the trunnions to the frame are not loose or have any slop in them that may have cause them to move from vibration.

What is odd is that from your description the blade is further away from the thrust bearing on the lower portion than the upper portion. This leads me to believe the top wheel is moving to the right ever so much. (looking at it with doors opened) That is the wheel that moves so this is where I suspect the problem lies.

Let me know if you find out anything else in the mean time. i will try to search for that recall. I am assuming there is no more warranty on it. Did you contact Delta and ask them if they run into this???? Probably the first thing I would have tried. I understand their customer service has improved since shipping things overseas. We will not give up just yet.

 

[larryc]

John
I had been thinking about the wheels moving under tension also. I used calipers to measure the distance from the wheels to the sheet metal wheels cover and could discern no difference tensioned or untensioned. I tried your ideas and again could find no difference.
I did replace the 3/4" blade I had installed with a 1/2" blade and there was a great improvement.
The blade is still to the right but not so far and both thrust bearings now work.
I need to cut a ZCI for the new blade location.

 

[duncsuss]

I was about to talk about the long bolt that goes through the riser-block to hold the top & bottom parts of the C frame together, but several times you've said it makes no difference if the blade is under tension or not.

My thinking: a larger blade runs under greater tension than a smaller blade; this tension could be pulling the top of the C frame downwards, which would cause the blade to shift to the right.

It's unlikely to be this given your other descriptions. Sorry, I can't think of anything that JT and you haven't already covered.

 

[jttheclockman]

John
I had been thinking about the wheels moving under tension also. I used calipers to measure the distance from the wheels to the sheet metal wheels cover and could discern no difference tensioned or untensioned. I tried your ideas and again could find no difference.
I did replace the 3/4" blade I had installed with a 1/2" blade and there was a great improvement.
The blade is still to the right but not so far and both thrust bearings now work.
I need to cut a ZCI for the new blade location.

Well Larry if the wheel is not moving to the right then I am at a loss. Now you mention that with a thinner blade the alignment improves. As I said i basically have the same saw but mines is over 30 years old. They have not changed much over the years. Just the way the motor mounts and as I said i do not have the quick tension bar. i use mine with all kinds of blades. I use a 3/4" lennox carbide saw blade for resawing. It takes everything that spring can hold to tension it. I was at one time going to change the spring but have not yet. It still is doing its job. Right now I have a 3/8" metal cutting blade on it. My point is never has the blade size made a difference in the alignment of the centering rigs and the thrust bearings.

I will say this though every blade and every blade manufacturer make blades with different materials and the flex of the blade is affected. Within each size blade there are different formulated blades and this is designed for the materials being cut. It maybe the blades you are using the flex of them is tougher and more stiff and can not wrap around the wheels as sharply as some others. It maybe that they require more tension than you are applying. There are makers of blades that promote low tension blades for this reason. Again it is the make-up of the blade. The trunnion assembly parts were made of pot metal and they were cracking and they had to beef those up. There were a few other things that were shortchanged when they went overseas and left the USA. To sell cheaper they must make cheaper.

As far as the zero clearance plate goes, if the blade rides where it is suppose to I never worry about those. I think I mentioned it before, you should see mine. It has more cuts in it and all different angles. I scroll with mine and for years I have used the original blade aligning system that you show. I have since changed to the Carter system whenever I scroll. It keeps the blade better aligned and won't twist and turn. If i want a Zero clearance plate now i just place a piece of tape over the plate and that solves that.

If i run into any other suggestions i will post. Hopefully you can use the saw. I still would call Delta and see what they have to say. They may send you new parts for free. Or know of a recall on those saws. They are a workhorse in the field though and that is why they have been copied over the years.

 

[Gary Beasley]

Have you looked at the bolts that hold the lower guide assembly onto the frame? Something may have got loose and let it move a bit.

 

[larryc]

Have you looked at the bolts that hold the lower guide assembly onto the frame? Something may have got loose and let it move a bit.

They are machine screws and I thought about removing them and putting shims to move the lower bracket to the right, but those screws are not coming out without a lot of persuasion.

 

[Gary Beasley]

Have you looked at the bolts that hold the lower guide assembly onto the frame? Something may have got loose and let it move a bit.

They are machine screws and I thought about removing them and putting shims to move the lower bracket to the right, but those screws are not coming out without a lot of persuasion.

Yeah if they're that tight you know it didn't start there.