Bandsaw set up woes- Ripple/wandering blade!

[Dissolve]

Hello,

I've been struggling to get a clean cut using my bandsaw and it's time I spent the time to fine tune it. It's a Record BS350 bandsaw and when I first got the saw it was set up and I remember it cutting much better than it does now. I have a Tuffsaws 3/8ths 6tpi blade currently fitted and it really isn't that old. I've also tried another 1/2" tuffsaws blade with similar results.

My problems are when cutting any wood above 10mm in thickness, the teeth seem to wander in the cut left to right, and the blade fails to cut straight when performing any kind of rip cutting or smooth when sawing curves.

I have tried released all the guides to ensure none of them are interfering, I've cleaned al the tyres and checked the tracking, the blade runs consistently right in the middle of the tyre.. the only thing that seems to make any noticeable difference is the tension of the blade, I have tried releasing the tension until the blade wobbles/vibrates visually and then tightening it just enough so that the blade runs true/straight.

I'm still getting this ripply/uneven cut. Even ripping 10mm plywood against the rip fence, the blade seems to twist left and right slightly and you can see the teeth deviating slightly as it cuts the material. It pushes through with ease, it cuts quickly and effortlessly but it doesn't want to cut striaght/smoothly at all.

Has anyone got a suggestion of something else to try?

 

[Random Orbital Bob]

There was a thread here only a fortnight ago on this very subject. I suggest you go through the entire setup beginning with no guides touching anywhere. By far the most critical setup step is the blade tension. It is usually the case that people set it far too lightly. Then, like a poorly tensioned hacksaw blade the blade wracks and buckles when the teeth meet resistance. Completely ignore the "tension meter" inside your top wheel house as its useless. Tension the blade using the quick set lever with the guides about 6" above the table. The blade should deflect no more than 1/4" max when pushing it with "reasonable" pressure.

Theoretically, for the best tracking the gullets of the blade should be in the centre of the tyre though that is a small difference to what you're reporting. Then the thrust bearings should be set to a whisker away from the blade. The test is that they shouldn't turn when the blade isn't touching any wood but as soon as wood is pushed into the blade they should begin to rotate. Side bearings should be a tad behind the gullets.

Before you set the guides, with everything not touching the blade and the tracking and tension set....the blade should run without chatter. If that test is passed then go ahead with the guides.

If the wheels are OK etc then its almost certainly that despite your report of sharp blade then the blade is actually not sharp (maybe got some metal unbeknownst etc) or more likely the tension was insufficient. Some people set their tension so they can hardly deflect the blade at all its so tight. So tension is routinely too loose in many cases.

 

[Grayo]

When you tension the blade are you just using the knob and then do you then push the tension leaver over ???. I have the BS300

 

[RogerP]

A Steve Maskery DVD will be your answer ...

http://www.workshopessentials.com/shop/

... and just now looks a good time to buy

or just the Bandsaw DVD ...

http://www.workshopessentials.com/shop/index.php?route=product/product&path=35&product_id=53

 

[marcros]

(As I understand it) You are supposed to have 3 teeth in the wood at a time. So 6tpi are about right for 1/2" timbers. My starting point would be to try a coarser blade- I tend to leave mine with a 3tpi one in, which will cope with most things. On thin stuff, I would change it if I needed a finer cut but more often than not I just allow an extra couple of passes on a planer if it's a straight cut.

When I bought my saw there was an odd blade with it. It was inch by 10/6 tpi meaning it had 6tpi then 10 then 6 then 10. I thought this would be great- inch would cut nice and straight etc. it did exactly what you describe on 1" stock. I still haven't discovered what that blade is really used for.

 

[Richard863]

My 350S had the same problems, due to the table and fence being setup or should I say not setup. The blade was inline the the removal track. Not only were the 2 mitre tracks not parallel to each other nor were they to the blade removal slot.
So from the start I fitted a new wide blade got the tracking and tension correct, then decide which mitre track you want to use as a reference, in my case the RH one with no blade guides set put a steel rule against the flat of the blade slacken the 2 allen bolts holding the table make the mitre track parallel to the rule, lock the table bolts. Place the rule against the other side if the blade then make the fence parallel to the rule. Finally set up the top and bottom guides just missing with the welded join between them.
If this was a multi thousand £ band saw I would have expected better, but you have to compromise, the whole procedure took one day by the suck it and see method.
Hope this helps.
edited:- I am a little concerned over when the blade is tracking on the top wheel in the centre of the tyre with a wide blade the teeth are just hanging over the edge on the bottom wheel, I would have thought it too should be on the centre of the tyre.
Any comments please I will try and get a answer from Record on Monday.

Richard

 

[Dissolve]

My 350S had the same problems, due to the table and fence being setup or should I say not setup. The blade was inline the the removal track. Not only were the 2 mitre tracks not parallel to each other nor were they to the blade removal slot.
So from the start I fitted a new wide blade got the tracking and tension correct, then decide which mitre track you want to use as a reference, in my case the RH one with no blade guides set put a steel rule against the flat of the blade slacken the 2 allen bolts holding the table make the mitre track parallel to the rule, lock the table bolts. Place the rule against the other side if the blade then make the fence parallel to the rule. Finally set up the top and bottom guides just missing with the welded join between them.
If this was a multi thousand £ band saw I would have expected better, but you have to compromise, the whole procedure took one day by the suck it and see method.
Hope this helps.
edited:- I am a little concerned over when the blade is tracking on the top wheel in the centre of the tyre with a wide blade the teeth are just hanging over the edge on the bottom wheel, I would have thought it too should be on the centre of the tyre.
Any comments please I will try and get a answer from Record on Monday.

Richard

I have yet to use anything wider than a 3/8" on mine, but I have noticed the blade seldom runs in the same place on either wheel, it's consistent though and nothing seems to slip, the blade doesn't appear to "wobble" visibly, but the teeth wander side to side slightly in the cut. I might buy a coarser blade, maybe try a 1/2" and see what's what.

For a "general purchase straight cutting blade" would a 4tpi 1/2" blade seem about right?

Can anyone offer some advice choosing between the Tuffaws Supertuff Premium and Supertuff Carbon? I don't think the BS350 is likely to struggle with tensioning a 1/2" Carbon blade but is their any reason to choose the Carbon over the Supertuff Premium? I don't really know if being a thinner material would be of benefit to me with a relatively large saw, or if the Carbon is harder wearing?

Once I have the new blades I'm going to dedicate a day to starting from scratch and setting it up with a fresh blade, what's everyones thoughts on tensioning then? The record power DVD seems to edge on the side of under-tensioning and only tensioning so that the blade can't slip, but from experience I've noticed some pretty visible blade wobble (side to side) due to the blade being under tensioned!

 

[Random Orbital Bob]

One of the variables that contribute to the straightness of cuts is the blade width...the wider ie more metal, the less likely it is to wrack in the cut and go off course. Using that thinking then a 3/4" blade as long as its possible to tension it properly would be about as robust as your saw would allow. The other thing is of course how many teeth are in the cut at once. The rule of thumb is that 3 teeth should be in the cut at any one time so the tpi of the blade is important when you consider how thick the stock you're cutting is. Generally speaking, the greater the tpi, the finer the finish of the cut BUT the less easily the blade will clear out the sawdust so a 6tpi blade on 6 inch green timber would be useless whereas a 3 tpi would be better.

A 4 tpi 1/2" blade isn't a bad all round compromise for a range of thicknesses that both gives some stability based on thickness AND removes a fair amount of dust fast enough AND will have 3 teeth in the cut for many thicknesses as long as the stock isn't too thin.

Personally, I favour 3/8" 3 tpi but then my most common activity is cutting green wood turning blanks.

One thing worth mentioning. Are you experiencing these ripple cuts after cutting any green or wet timber? Or is it all dry stock? I only ask because I find when I cut a lot of wet timber the sawdust and resins tend to build up on the left side of the blade after about 20 minutes. That has a profound effect on the tracking and sends it doo lally so the blade is apt to move back and forth due to uneven purchase on the tyres. This is easily remedied by using a sharpened wall paper scraper and gently scraping the blade (while running) being careful not to hit the teeth. Once this procedure is done it completely restores the original tracking dynamics and the blade once again runs true with no wobble

 

[Dissolve]

Hi Bob,

It's all dry timber, I've experienced the resin build up before but I've double checked the blade/tyres for build up.

I'll probably go ahead and order maybe a 1/2" 3 tpi and a 3/8" 4tpi seeing as I won't be cutting horrendously thick/sense material.

I still can't find the reason why the 6tpi blades have wandering teeth! Even rip cutting some 12mm mdf for jig making had the teeth wandering side to side!

The blade doesn't wobble when running, perhaps I'll try the Supertuff Carbon blades because they're made from thicker material!

 

[Random Orbital Bob]

worth a try. I know you've already been through this but the problem does sound suspiciously like an under-tensioned blade. Have you done the test where you set the guides circa 6" above the table and pushed with a "reasonable" force and the blade deflects no more than 1/4"? Granny and sucking eggs I know...I'm running out if ideas now without actually seeing it in action

See how it behaves with a new blade, new information is always handy because it may remove one of the variables. Keep us posted when Tuffsaws stuff arrives.

 

[Steve Maskery]

Ask Ian's advice regarding the difference between the Premium and Carbon blades. I've just ordered some 1/2" 4TPI Supertuff Carbon for general use in our Community Workshop. Not ideal for anything, but a good compromise for many things.
S

 

[blackrodd]

One thing worth mentioning. Are you experiencing these ripple cuts after cutting any green or wet timber? Or is it all dry stock? I only ask because I find when I cut a lot of wet timber the sawdust and resins tend to build up on the left side of the blade after about 20 minutes. That has a profound effect on the tracking and sends it doo lally so the blade is apt to move back and forth due to uneven purchase on the tyres. This is easily remedied by using a sharpened wall paper scraper and gently scraping the blade (while running) being careful not to hit the teeth. Once this procedure is done it completely restores the original tracking dynamics and the blade once again runs true with no wobble[/quote]

I have noticed the resin and saw dust build up on the rubber tyres and inside of the blade as you say.
I put this down to the fact that a rubber tyred bandsaw was not intended to "convert" wet timber.
As you're aware, The band mill has steel crowned wheels, that were lubricated with diesel oil in a box on both top and bottom wheel, that also had the large cleaner brush fixed to it, and brushing the wheel clean.
This set up did not allow for the debris, and saw dust to build up.
Also the tracking set up on these larger machines was to have the saw blade gullet projecting 1/16" over the wheel edge, allowing the sawdust an easy escape, and not to foul the wheel and tyre.
The teeth were between 60mm and 80mm long and "swaged" not set alternately, as a circular blade.
This was tracking was common to the smaller band re-saw also, which made deep cutting far easier and safer.
Regards Rodders

 

[Benchwayze]

I use a Bb tuning fork, and ping the blade. When it's 'in tune', I know the tension is right. 8)








































Don't believe me?




































Oh well!

 

[rspsteve]

I use a Bb tuning fork, and ping the blade. When it's 'in tune', I know the tension is right. 8)

Don't believe me?

Oh well!

Video it or it never happened...lol


Did you ever sort the problem?

 

[MMUK]

I use a Bb tuning fork, and ping the blade. When it's 'in tune', I know the tension is right. 8)

Don't believe me?

Oh well!

Video it or it never happened...lol


Did you ever sort the problem?

He must have, it worked fine rough cutting my woodies to shape the other week :mrgreen:

 

[joethedrummer]

I use a Bb tuning fork, and ping the blade. When it's 'in tune', I know the tension is right. 8)

Oh b.gger,,I"m in the wrong key,,I"ve been in D sharp,,!!






































Don't believe me?




































Oh well!

 

[Benchwayze]

Sawin' is believin'