Bandsaw not cutting straight

[Jess Wetherhold]

I don't really know what else I can do here. While running the saw there is obvious wobble in the blade movement like it is moving front to back (not side to side so much.) The carter guides are perfectly adjusted, the tension is set and the tires on the saw are brand new. I have no idea what is causing this but I can't get close to a straight cut to save my life. About 1/2" in the blade will twist in either direction.
The only thing that come to mind is that somehow the wheels are out of balance? The reason that I installed the new tires is because I had my first blade break and it chewed up the old ones. The saw hasn't been right since.

Any help would be appreciated since my jobs are stalled until I can figure this out.:confused::confused:

[Mike Lipke]

Sounds like a bad blade, or blade weld.

[Glen Blanchard]

Jess - Have you confirmed that your wheels are coplaner? I don't know that that would cause this problem, but if you are troubleshooting be certain to do this. Additionally, do the bearings seem alright?

[Jess Wetherhold]

I have tried 3 different blades all with the same results. The carter guides are brand new but I did reinstall the old ones and had no change.

[Julian Nicks]

You need to true up your tires. I had the same problem after installing carter urethane tires.

[glenn bradley]

it is moving front to back (not side to side so much.)

This is normally a symptom of a bad weld but three bad blades in a row isn't likely.


The carter guides are perfectly adjusted

I question how this could be with the blade moving forward and back? You could not get the thrust bearing set correctly with this happeneing. Just food for thought.


About 1/2" in the blade will twist in either direction.

The poor cut could be result of the blade moving front to back enough to place the gullet between the bearings and ruin the tooth set. Again, three times in a row would be odd.


The only thing that come to mind is that somehow the wheels are out of balance?

I think you would notice the saw dancing a bit if they were out of balance. My gut tells me a wheel is out of true. If you look at each wheel perpendicular to the axle, are they running true with no visible wobble?

Where I'm going with this is that perhaps there was some damage when the blade got tangled up in there(?). I had an old 14" that had a wobbling top wheel. It did what you describe. I'm kind of reaching a bit here but would like to help you figure this out.

[Jess Wetherhold]

Glen- I believe you are correct. The saw does have a lot of vibration while running and does a little dance. I think I notice the top wheel "wobbling" a bit but it is hard to tell because of the vibration.
I am not certain how to go about making the wheels true. Any suggestions? Sorry to be such an idiot but I have never had anything like this happen.
Thanks

[Tony Ward]

Jess

Have you checked the blade tension - a number of bandsaw users who use the pluck method (that is plucking the blade in the centre of the longest unsupported side and listening to the resultant sound) recommend the tension be set to correspond with the "A string" ~ http://www.guitarforbeginners.com/onlinetuner.html

It works for me!

[glenn bradley]

I am not certain how to go about making the wheels true. Any suggestions?

I am far from an expert but, I'll give it a go as far as isolating the offending item goes.



With the blade off and the saw unplugged does the saw run as it did before, vibration-wise? If so, we can eliminate the lower wheel, pulleys, etc. from our trouble shooting.
With the blade off and the saw unplugged, spin the upper wheel by hand and watch for anything other than nice smooth, true rotation.

I'm assuming one of these tests will fail and then we can move on. If both these tests pass; with the blade off and the saw unplugged (sorry to keep harping on that but, safety first) feel around the wheels and see if you have lost a chuck of material that may be causing the post-blade-break vibration and bad behavior. We're looking for something that may act like losing a wheel weight on your car.

If all these checks pass inspection we are really starting to stretch what help I have to offer. Unless the saw fell over, I doubt your wheels suddenly lost their co-planer relationship. I don't know that the symtpoms you describe would come from this anyway. Also, did you mention what brand/model this saw is? That may help.

[Jess Wetherhold]

It is the Rikon 14" Deluxe. The saw runs smooth without the blade and just the lower wheel turning. I turned the upper wheel and then used a dial indicator against the tire. It has a high spot and is .01 out.
The tire is trimmed correctly and there is no debris between it and the wheel.:confused:
I did find the weld on the tire to stick out a bit so I sanded it down but it made no difference.

[Chris Padilla]

Grab either wheel and see if you can rock it at all to and fro. In other words, I wonder about bearings. Is there any noise when you spin them by hand? Any chance the wheels are loose? It could be a tension issue, as well...any problems tensioning up the blades...any change as you change tension while running?

[Jess Wetherhold]

I have trouble tensioning with larger blades. I just installed a new 5/8" and had to put all of my muscle into getting it tensioned correctly.
Also, This blade doesn't wobble nearly at all. I am thinking that I may have used the other blades with the old bearings (which 1/2 were frozen by the time I checked) and the blades perhaps got bent or twisted in places?
Anyway, there is a strange light grinding noise coming from the top wheel that only sounds through 1/2 the turn. The bearings look new and move freely and the wheels are solid on the saw (no movement when I yank on them.)
I wouldn't think I'd have to put so much elbow grease into getting the proper tension so that is making me think something is up there. What, who knows.
I did take everyones advise and trued up the wheels. That seemed to help things a bit. Why the wheel is running .01 out is another mystery.

[Chris Parks]

I seem to recall someone having trouble with a seized tension adjuster, I have no idea what saw it was on though. With the saw blade on and tensioned can you turn it by hand and see it happening or does it only happen with the saw running? I would have said a blunt blade initially, but unlikely to be with three blades to compare. The tensioner if seized could lead to this also.

[Alan Schwabacher]

A bad weld can cause the problem you note. One way to distinguish the blade from other sources of this problem is to mark the blade and turn the wheel of the unplugged saw by hand. Note where the blade moves forward and back. If it's always at the same spot on the blade, it is a blade problem. If it's always with the wheel in the same position, it's a wheel problem. It it's apparently random you don't know, but it's probably not the blade.

[David Christopher]

Jess, my 14" rikon started acting up and doing the same thing you are talking about....I called rikon and the tech guy had me fixed in less than ten minutes....all I had to do is ajust the top wheel with the 4 little bolts on the axle

[Jess Wetherhold]

My plan was to call Rikon today but I always seem to miss then since we are 3 time zones apart. I will definitely do that tomorrow.
I did switch from the new blade to the old and there was a world of difference. The old blades wobble all over the place but the new one is pretty alright.
I would settle but I have 20 boxes to make and I don't think I could deal with the issues the saw has now.
Oh- when turning by hand you don't notice the wobble, just when it is running.

[glenn bradley]

I would settle but I have 20 boxes to make and I don't think I could deal with the issues the saw has now.

I was away for awhile but it sounds like you are making good progress. I settle for some things and not for others. I would work this one a bit more before I was OK with it. Sounds like you are on track and Rikon tech support has always been reported as very helpful. Glad things are moving along.