Bandsaw blade wandering

[LarryS.]

Hi all,

I've been using my Record BS350 very successfully over the last few months with no issues. However last night I was cutting some 2 inch oak and hit a screw that was within it.

The blade I was using was half inch

After I removed the offending piece of wood I found that as soon as I started a cut the blade would head off at an awful angle, so I had to stop. I tried checking / adjusting things but to no avail. So decided it must be a blade issue and took it off.

I've put on a slightly smaller blade this morning, and re-adjusted using the youtube video everyone links to. Now that blade "wanders" i.e. does not want to cut in a straight line.

The other thing I've noticed is that the system that the top bearings are mounted on is slightly loose - could that be causing the issue, or is that as design (I haven't noticed it before, but then I haven't had to touch it before)>

Any help appreciated


Paul

 

[marcros]

what is the tooth count on the new blade, and what are you attempting to cut with it? is the cut vertical, but wandering, or is it dished?

 

[Alexam]

Hi Paul, first thing is the blade damaged by the screw ?

If not,is the Video the Alex Snodgrass one and are you managing to get the blade running freely ( without guides or rear bearing near the blade ) with the gullet of the teeth in the centre of the top wheel. That's the first priority before closing in guides and bearings. ???

Once the guides and bearings have been brought to the correct position, is the blade remaining where it should be when run under power??

Is the blade running true verticle 90° to the table front and back and side to side ??

If all these things are correct, then I cannot see the problem unless you are trying to cut the wood too fast and it's filling the teeth with sawdust and pushing the blade out of line. Is it a Tuffsaw blade?

Malcolm

 

[LarryS.]

what is the tooth count on the new blade, and what are you attempting to cut with it? is the cut vertical, but wandering, or is it dished?

4TPI on new one, half inch blade, cutting 18mm plywood (so nothing strenuous)

first blade was 3/4 inch

 

[LarryS.]

Hi Paul, first thing is the blade damaged by the screw ?

If not,is the Video the Alex Snodgrass one and are you managing to get the blade running freely ( without guides or rear bearing near the blade ) with the gullet of the teeth in the centre of the top wheel. That's the first priority before closing in guides and bearings. ???

Once the guides and bearings have been brought to the correct position, is the blade remaining where it should be when run under power??

Is the blade running true verticle 90° to the table front and back and side to side ??

If all these things are correct, then I cannot see the problem unless you are trying to cut the wood too fast and it's filling the teeth with sawdust and pushing the blade out of line.
Malcolm

Malcolm, I inspected the original blade and couldn't see any issues with it, but presumed it was damaged because of the sudden issue of it wandering off-line, thats when I then put in the new blade

Yes I followed the snodgrass video and checked the run of the teeth on the wheel.

On the blade running at 90 degrees, are you basically asking if the table is in alignment ?

 

[Alexam]

Thats right Paul, table alignment, just trying to think of anything that would be out of line. I presume that you re-tuned the smaller blade and adjusted tension when changing blades. Also possible tension may be out ?

Malcolm

 

[LarryS.]

Thats right Paul, table alignment, just trying to think of anything that would be out of line. I presume that you re-tuned the smaller blade and adjusted tension when changing blades. Also possible tension may be out ?

Malcolm

table alignment was one i skipped, but the blade is "wandering" i.e. moving left and right, so don't think it's that, but I will check.

Tension I've found a bit of a black art, so I'll do that again

thanks for the help


Paul

 

[lurker]

My knee jerk is you have damaged the "set" of the blade

Bung a new one in and see what happens

 

[marcros]

if you are attempting to cut in a straight line- you are, so guides shouldnt be a factor
and the blade is appropriate- 4tpi in 18mm ply shouldnt cause an issue
I would suggest that the issue is either that you are pushing the material in too quickly- unlikely, you would have to go really fast to jam up the teeth in that ply.
or the tension is too slack.

if the blade is staying on the wheels, the tracking probably isnt the issue.

 

[LarryS.]

thanks marcros, i'll be checking the tension.

the other confusing part is the first blade going weird after hitting a screw, but with no visible damage / issues with it

 

[skipdiver]

I'm with lurker, you've bullocksed the set hitting the screw. Try a new blade.

 

[marcros]

it is a new blade though

 

[worn thumbs]

Just to be clear,were you using a rip fence at the time?

 

[skipdiver]

it is a new blade though

Oh! That'll teach me not to comment without reading the posts thoroughly.

 

[dzj]

Is the replacement blade new or just one you had laying around the shop?
Hitting a screw should only damage the blade.
Like previous fellows suggest, a new, sharp and well set blade will probably solve your problem.

 

[pike]

Is the new blade never before used? If not and if you've got any more blades try another. I found that I damaged a few blades in the first 6 months of casual weekend bandsaw use, as I'd never had one before and although I understood all the setup steps it didn't really click. I'd forget something or not realise how important the rear guide is to stopping the blade teeth being damaged on the side ones etc.

You could also check the blades and wheel tyres to see if they need a clean.

 

[YorkshireMartin]

Tension at a guess.

Depending on the thickness of the steel for the new blade, it may require more tension than the previous one, despite being narrower. Tuffsaws, for example, make ultra thin gauge wide blades because "weaker" machines often cannot tension a standard gauge blade of the same width.

 

[AJB Temple]

He HAS put a new blade in.

You say blade is wandering left and right - i.e. laterally. Suggests tension is far too loose and maybe that you have not wound the top guide down far enough so that there is a lot of blade projecting above what you are trying to cut before the blade reaches the bearing guides. Don't press too hard - let the saw do the work.

 

[pike]

He HAS put a new blade in. .

At first he said he'd put in "a slightly smaller blade". Later he did say new, but I thought I'd double check it was new as in never before used as opposed to just newer than the other one. The main problems I've had with bandsaws is dirty, damaged blades or wheel tyres.

 

[Alexam]

Good point pike. There may be few operators that actually clean their blades from time to time and the residue can build up and increase the kerf of the blade. Quite easy to do and doesn't take long with a small wire brushand cloth and moving the blade by hand when the power is disconnected.

Was it a NEW blade put on or just 'another one'? How are things going now?

Malcolm