Bandsaw help needed (video of problem)

[Tom DiBiasio]

I am having an issue with my bandsaw that I hope someone can help with. I created a short YouTube video to demonstrate my problem. ( I hope I am not breaking any forum rules by posting a link to YouTube?? If so please remove and inform me so I don't do it again in the future. )

As you will see in the video the blade is "pulsing" for the lack of a better term, front to back with both guides full disengaged. Here are the saw details:

Grizzly G0457 (14")
timber wolf 1/2 inch blade
tension knob set to 1/2" on back scale
table removed
both guides fully disengaged

here is a video
https://m.youtube.com/watch?v=qfGTITDdZT4 (https://m.youtube.com/watch?v=qfGTITDdZT4)

my question is - is this normal?? Seems not but I thought to ask that first. Any suggestions would be appreciated. Of course I could call Grizzy, and most likely will, but it is Saturday evening and I thought to gather the guidance of this group as well.

thanks in advance....

TomD

[Justin Ludwig]

You made the video private.

[Van Huskey]

Once the video is up you will likely get more info.

Until then I have a couple of questions. Is this a new saw? If not has it always done this and if it hasn't what have you changed since it worked properly?

[Tom DiBiasio]

Sorry... video should be public now

can someone confirm if it viewable now?

[Van Huskey]

Not normal. The video probably answered one of my questions, there seems to be enough dust on the saw that it is not new. So is it new to you and if not has it always done this and if it hasn't what have you changed since it worked "correctly"?

[Darcy Warner]

Reminds me of a crappy weld job.

[Tom DiBiasio]

It is hard for me to say if this has always done this, for years i did not use it much and when I did I had a small 1/8" blade on it that i used for making curved bandsaw boxes and to trim pen blanks. With that small blade I did not notice this happening. Within the last few months I dusted it off and put a old resaw blade on it to make some cedar lining for a blanket chest. I am now onto a more normal sized project, a cherry hall table and put this blade on to cut some templates for legs. With the resaw blade I noticed the same but I wrote that off to possibly the age of the blade. The only other new blade I have are the 1/8 ones so I guess I will have to buy another wider one to try. Both of the blade doing this were stored for a few years hanging on a screw in a stud wall and they had a little rust that I steel wooded off before putting in the machine. Could the blade just have gotten tweaked out of shape from sitting so long?

thanks for the fast responses

[Van Huskey]

My guess is the tires are wonky. Did you run the small blade when you put it "back in service" or move directly to the wider blade? If you didn't run the small blade try putting it back on nd if the tires have issues it is likely the small blade ill exhibit similar issue.

[Eric Schmid]

Reminds me of a crappy weld job.

My thought as well. The only time I had a blade do this on me was right before the weld broke. Do you coil your blades before hanging them?

How is the blade tracking over the wheels?

[Van Huskey]

My thought as well. The only time I had a blade do this on me was right before the weld broke. Do you coil your blades before hanging them?

How is the blade tracking over the wheels?

While a poor weld certainly can lead to similar issues the fact that he got the same movement from another blade lowers the chances that it is the weld since that would require both welds to be bad. That is accuming I read and understood that he has had 2 blades do the same thing since dusting the saw off.

[Andrew Hughes]

Just looks like a bad weld or a kinky blade to me.Could be the tires need some cleaning I would start with the blade first.

[Floyd Mah]

I would guess that you have a bad blade. A bad weld or your blade had hit something hard and got bent. A blade flaw would have periodicity related to the length of the blade. A wheel flaw would have a periodicity related to the wheel circumference. Use a piece of wood, or some other marker to identify the maximum excursion of the blade backwards. Mark the blade with a Sharpie or a piece of tape. Turn the upper wheel until the blade strikes your piece of wood again. If you see the same mark (from the Sharpie) near the wood, it's the blade. If you find that the previous mark is the distance of one wheel circumference, it's wheel connected.

[Paul Richard]

Can u rotate the wheels by hand with the machine off and unnplugged? If so hold a sharpie by the guide bearing such that it marks the blade at the "pulse". Someone correct me if I'm wrong, but if it's happening at multiple spots along the blade then I would focus on the tires/wheels. If it's only one spot on the blade then swap out the blade and do the same exercise. Try to eliminate one potential problem at a time, because this could be caused by more than one issue.

Is the machine running smoothly otherwise, meaning without any out of the ordinary vibration?

[Ken Fitzgerald]

Have you tried another blade?

[Mark Gibney]

I had this exact problem on a Grizzly bandsaw this week (17").

The blade was kinked, and the tires had gunk on them. I cleaned the tires, put on a new blade and it ran perfectly.

I also increased the tension a bit.

[Van Huskey]

Have you tried another blade?

If I read it correctly he has had the issue with two blades this go round, which is why I am leaning to tires instead of blades, but he needs to verify he has indeed used two larger blades and had the same issue.

[Justin Ludwig]

I'm no expert on bandsaws, far from it. But I had that problem and it was my blade(s). I had two blades that were kinked. I also made my wheels co-planer and that made things even more smootherlyest.

[Lee Schierer]

I've see that exact problem when a kinked blade was used. It is pretty easy to kink a small blade when coiling it if you aren't careful.

[glenn bradley]

I'm in the "tires" camp. Same problem with different blades? Probably tires. Same damage to both blades due to use or handling methods? Possible.

[Tom Welch]

I had the same problem with my Mini Max. Changed the blade, problem went away.

[Matthew Hills]

The advice to unplug and turn the wheels manually to determine when the blade is at maximum deviation is the right next step...


Like others, I've seen this front/back error with a bad weld, and that made sense to me. Does a bad tire/wheel/bearing tend to throw the blade front/back like this, as well?

Matt

[Ken Fitzgerald]

If I read it correctly he has had the issue with two blades this go round, which is why I am leaning to tires instead of blades, but he needs to verify he has indeed used two larger blades and had the same issue.

Thanks Van. I failed to read that about the resaw blade. A 1/8" blade is so small that I would be a little hesitant to confidently compare it to a 1/2" blade.

[mreza Salav]

Other thing to check (other than blade and tires) is the wheel spinning true or is wobbling. Remove the blade, turn off the saw and turn each wheel (particularly the upper wheel) by hand and watch the front edge of the wheel at one location, this is like a balanced wheel on a car or not.

[Bob Cooper]

Sounds like both blades were hung up in storage together. I'm thinking they r both reflecting this

[Tom DiBiasio]

First off thanks so much for all the responses, this group has an amazing amount of experience!!

we had a hell of a snow storm last night so took me some time to get back in the shop to try some of the suggestions after shoveling out. I tried a few things:

cleaned both tires really well, bottom one had some pitch build up but not bad. Top one has "slight groves" from what I expect is from using the saw primarily with a 3/16 timber wolf for fine curves in bandsaw boxes, and not releasing tension for some time when I first got the machine, learning curve....sigh. Never the less I have cleaned them well and reinstalled a 3/4" resaw blade I had, not new and in fact stored in the same manner as my other used blades. So I took another video with this one for you to see: https://m.youtube.com/watch?v=ArIe7WJQIqo (https://m.youtube.com/watch?v=ArIe7WJQIqo......as) As you can see it is pretty much doing the same thing, but maybe a little less.

So the only other new blade I have is another 3/16 - so I mounted that one and took another video: https://m.youtube.com/watch?v=qDQ7XI7Dd6I ....on this test I snugged up the thrust bearing to see if I could notice any lateral movement on the smaller blade... to my eyes I do not detect any pulsing with the new blade, but due to the size it is hard to tell for sure. What do you think?? It seems I may have been fooled by two twisted blades?

I am going to the woodworking show in CT next weekend so I will look for some new blade while I am there to pick up to see if a wider new blade confirms a twisted blade.

thanks again for any last opinions on this issue.

[Floyd Mah]

Kinked blades can be examined. If you had marked the suspect blades with a Sharpie, you might find an obvious bend nearby. Try taking the blade off the saw and running a straight edge along the back to look for a front to back bend. Also press it against the table surface and see if there is a side-to-side bend. If the blade is not too large, you can even correct the problem, of course taking care to make sure that it remains flat when you check it against a flat surface. It might not be serviceable again, but it's worth a try. Since all band saw blades are made from flat stock originally and have been welded up, truing up a blade probably isn't that much different from what the fabricator did originally.

[Darcy Warner]

I think those two wider blades were not flat when welded or moved a bit when welded.

I get a little back and forth blade movement in my big saws, 18 to 19 foot long bands, but it's never bothered me cutting anything I do.

[Van Huskey]

OK so you have 2 old wider blades that pulse (but I assume did not pulse when last used) and 1 old and 1 new narrow blade which don't pulse. Correct?

If this is the case I swing over to the blade camp and think (if they didn;t pulse before) then it is a storage issue though I have never seen it happen under only the weight of the band. It would be quicker and likely cheaper just to order a new band but that is up to you. I would examine the weld with a straight edge and you can lay the entire band on a flat floor back down and see if it rocks.

Did you coil the bands before you hung them?