bandsaw is leaving deep marks after cleaning it


Recommended Posts

I gave my Laguna 14 SUV bandsaw a thorough cleaning and I must have misaligned something.  The cuts are much more rough now, leaving deep marks.  I tried 3 different blades from 3/8" 6 TPI to a 1" 2 TPI, including 2 brand new Timberwolf blades.  They all do the same.  I had some wood that I cut earlier before the cleaning, and one can easily see the differences.  I include two before and after pictures of the same piece of wood from both sides (one side cut before and one side after).  I tried different tensions, I adjusted the tracking several times, I cleaned and checked the tires, I adjusted all the guides.   I am out of ideas.   What could it be???

bandsaw before and after cleaning.jpg

Link to comment
Share on other sites

Do you notice new vibration or blade flutter?  Does your saw use weights to balance the wheels? Many use drilled locations for balancing but, some use weights.  Check your tires thoroughly for any pieces that may have gotten knocked off.

Link to comment
Share on other sites

I did the "flutter test" and the blade flutters occasionally but also minimally.  I am not seeing any weights.  There is a way to adjust the tracking.  And I did check the tires carefully again just now.  They look normal.  The marks on the wide resaw don't bother me too much, I will joint and plane it at some point anyway.  But the small pieces (top pictures), where the effects are more pronounced (with the narrow 6 TPI blade) makes the bandsaw unusable for me (I need to make hundreds of cuts).

Link to comment
Share on other sites

I did move the table!  I went back and checked the alignment however and the blade is still a perfect 90 degrees to the table and parallel to the miter slot.  I also strengthened the mobile base.   Anything else I need to align?  I did my best to put the gullets in the center (I can't do that for the huge 1" blade).   One thing I noticed is that the left side of the blade leaves much deeper marks, and that's true for all 3 blades.  Is that normal?

This is so frustrating!  I have this expensive machine that worked fine and now it's a very heavy door stop and too big even to be next to the door....

Link to comment
Share on other sites

Obviously something changed.  It sounds like you have run through the original alignment steps outlined in the manual.  We have to assume it is something that is not included in those procedures.

Make a cut in some thick (a couple of inches) material free hand.  That is, do not involve the fence or the miter gauge.

If that cut is noticeably smoother than your current results we do not have a problem with the blade, tracking, or table alignment.  If the cut continues to be poor we have a blade, blade to table, wheel, or tire issue. 

There is always the possibility of fouled blades.  You would not be the first to have his guides setup wrong and damage the set on a blade.  Then through troubleshooting change out every blade you have doing equal damage.  I'm sure you know that the blade gullet should never move back enough to go between the guides. double check your thrust plate position.

Sorry, I started rambling.  I would like to know the quality of the cut when cutting freehand.

Link to comment
Share on other sites

This is very useful.  I did make some of the cuts freehand.  The ones on the top picture (which are about 1" size) were done free hand.   Having a problem with my guides such that they then immediately destroy all blades I run through them did not occur to me, but I don't think that happened.  For the small cuts, I opened the guides wide open so they never touched anything (should not be a problem to cut 1-2" without any guides), and it made no difference.   I will check them again carefully.

"double check your thrust plate position" -- sorry, what's a thrust plate?

On 6/4/2023 at 10:15 AM, gee-dub said:

thrust plate

 

Link to comment
Share on other sites

On 6/4/2023 at 10:57 AM, Woody the squirrel said:

This is very useful.  I did make some of the cuts freehand.  The ones on the top picture (which are about 1" size) were done free hand.   Having a problem with my guides such that they then immediately destroy all blades I run through them did not occur to me, but I don't think that happened.  For the small cuts, I opened the guides wide open so they never touched anything (should not be a problem to cut 1-2" without any guides), and it made no difference.   I will check them again carefully.

"double check your thrust plate position" -- sorry, what's a thrust plate?

 

Bearing guides use a thrust bearing in this position or, like mine, perpendicular . . .

523251195_thrustbearing.jpg.e96996b017736ded96ee8adc5b9ac37e.jpg

Your saw uses ceramic guides and I believe a ceramic plate in place of a rotating thrust bearing(?). Maybe I am using the wrong term.

You can kind of see where I am going with this . . . If the cuts are not as smooth as before when the fence or miter gauge are not involved it pretty well narrows us down to blade, blade movement, or something causing deviation in the blade path.

A loss of blade "set" can do this is why I wanted to look at the guide setup.  Improper tension can also cause flutter or cause the blade to "belly" during a tall cut.  Belly refers to a blade path that deviates from perfect vertical due to the drag at the bottom of the cut causing the bandsaw to push the blade too much from the top.

1525290312_BladeBelly.thumb.jpg.18e17112b7a4e96c5793bbbc481e0930.jpg

Since you have checked everything we can assume the problem will turn out to be something that makes us firmly plant our palm to our forehead.  I do not know that I could confirm damage to the blade set visually unless it were really drastic.  I won't bore you with pics of my (bearing guided) saw since I find it truly frustrating for people to show me how their (insert tool or procedure name here) works fine when mine does not.

If the table is 90* to the blade, you have the guides backed off, and cut free hand with poor results I am still looking at the blade, tires or a really high degree of vibration.  I know this is frustrating but, when the obvious does not show us the gremlin-at-work we have to start splitting hairs.

 

 

  • Like 1
Link to comment
Share on other sites

It looks like your missing a guide block on the upper right side, you should have guide blocks on the under side of the bandsaw bed. And if it's anything like my bandsaw the blocks should be almost touching the blade (my saw has bearings not blocks) your blocks aren't even close to the blade this may be your problem read your manual for setting up your saw guides properly. I know I was having problems with my bandsaw and when I checked the lower bearings one of the side bearings had fallen off it was an easy fix and worked great after I fixed it.

  • Like 1
Link to comment
Share on other sites

I second the Alex Snodgrass video suggestion; it doesn't hurt to walk through the steps again.  But first, I think Dave H is correct, you appear to be missing part of one of the guides.  Make sure your guides are intact.  

  • Like 1
Link to comment
Share on other sites

Thanks everyone, this is very helpful.  The ceramic part indeed fell off and needs to be replaced.  I have it on order.  But somehow I don't think this is the cause of the deep marks.  I was freehand cutting a one inch piece with a 3/8" 6 TPI (the top picture in the original post above).  The guides are there mostly to prevent drift, isn't that the case?  They cannot prevent small flutters.  Am I wrong?  

Could it be that something else in the bandsaw is not tight (e.g., the mobile base), causing the whole thing to shake a bit?  I can definitely shake it by hand, it's not sitting solid due to the base.  Anything else I should look at?

Link to comment
Share on other sites

You can certainly slip some shims under the base, but until that guide is repaired it's going to be the prime suspect.  

Meantime, watch the Snodgrass video.  Looking at your photo I think your guides aren't close enough to the blade.

Link to comment
Share on other sites

I think the blade is fluttering because of the missing ceramic guide.  The Snodgrass video might help you a little bit but you need that upper guide.  Our 14 SUV has the 1" Resaw King carbide blade and my ceramic guides are close to the blade but not touching.  My cuts are very clean and smooth even when resawing Mahogany/Walnut/Purpleheart/Padauk/Rosewood etc. at 10" or more.

image.thumb.jpeg.2b962ca6b40144a3a7f50ba012508a62.jpeg

  • Like 1
Link to comment
Share on other sites

Do not completely follow the snodgrass tuning method for carbide tipped bandsaw blades. It WILL result in the blade prematurely snapping.

#1 If you follow the snodgrass tuning suggestions and place the crown of the wheel on the gullet of the blade it will result in the blade breaking in short order. Make sure the blade is centered on the wheel so the crown falls towards the center of the band if not a bit rearward. This is complete contrary to the snodgrass tuning method, but he doesn't use carbide blades. I have about 8 broken carbide blades in my shop from his tuning method. Each blade lasted 6-9 months before snapping. I stopped using his flawed method and I've had a blade on my saw for 3 years now.

#2 Your guides are too loose and ceramic is missing. There should be the thickness of a piece of paper between the side guides and the band saw blade. The rear of the blade should be kissing the back of the band saw blade. Follow the laguna owners manual for setup up the ceramic blade guides. On my laguna saw i struggle to have the grip strength to get the guide knob tight enough and use a pliers. When i couldn't tighten the knob enough the guides would spread and cut quality went in the toilet. Yes the guides help prevent flutter that is generated from sawing. Flutter generated from insufficient tension is another issue.

#3 check that you have enough tension on the blade. The tension guide on laguna saws is a magnet and once you determine proper tension can be moved around accordingly. Tension is guess work unless you have a devise to test tension. I bought one of these https://www.eztension.com/  it's good to get close but don't treat it as the bible.

  • Like 1
Link to comment
Share on other sites

In rereading i should specify that the center of the band is the center between the bottom of the gullet and the back of the band. My comment of it being a bit rearward is because centering it from the teeth to the back of the band would leave the crown a bit too close to the gullet of the blade.

Band saws are confusing.

Link to comment
Share on other sites

Thanks so much!!   I'll wait till I get the ceramic parts and try again.  I originally had the guides next to the blade, but I was worried that the marks were caused by the blade hitting the guides, so I moved them out of the way to pinpoint the problem.  Bad idea.

Now that you mentioned it, I did use a very expensive carbide blade once, it broke very quickly, and I didn't buy any since.  Now I know why.   So much to learn!   (I don't use the bandsaw much, I try to avoid it because it's so unpredictable, but that's my fault.)

  • Like 1
Link to comment
Share on other sites

The most common thing Ive had cause deep saw marks is a slight kink or twist in the blade from a catch. You can check this by slowly rotating the blade by hand with the power off and watching the profile as it moves past the guides. Its difficult to bend a blade back so most folks relegate such a blade to rough cutting duties until its dull then toss it.

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Who's Online   2 Members, 0 Anonymous, 43 Guests (See full list)

  • Forum Statistics

    31.2k
    Total Topics
    422.3k
    Total Posts
  • Member Statistics

    23,784
    Total Members
    3,644
    Most Online
    cokicool
    Newest Member
    cokicool
    Joined