This is a question for those knowledgable about bandsaws. I have a Ryobi 9"
bandsaw, BS903 (I think...). I comes with a 1/4" blade. I'm trying to do a
straight cut through a piece of weed that is 2" high, and 1.5 inches thick
and about 2 feet long. I need to make the cut 3 inches deep. When I do it, I
can't get the cut straight, and it appears that the blade wanders a bit back
and forth. It's not much, maybe up to 1/8 of an inch, but it's enough to
make it very clear that it isn't a straight line. I have the blade guides
adjusted fairly tight, about 1/64" on both sides of the blade, and don't
think I could adjust them any closer. I'm thinking of getting a wider blade,
say a 3/8 6t blade. Any band saw experts care to comment on what I can do to
get a straight cut, and if a wider blade will help?
The manual is a bit fuzzy about adjusting blade tension, and I really have
no clue how to tension the blade. The manual just says to tighten it until
it makes a sound like a guiter string when you pluck it. wtf? Are they
yup, they are serious. I have a much larger model, but the
similarities should help.
Unplug the thing, and open up the covers to expose the blade wheel.
There should be a couple (in your case 3, but we are interested in the
wheels above and below the table where you cut. The blade wheels
~should~ have a thin rubber "tire" that helps cushion the blade from
the wheel. Inspect the blade, the tire, and the wheels to make sure
there isn't a bunch of caked up sawdust getting in the way along the
On my bandsaw, there is a little knob that allows me to tilt the top
blade wheel. Tilting the wheel ever so slightly allows the blade to
run closer to the exact center of the blade wheel. You know how a
pulley would have a concave surface to help align the rope? Well a
bandsaw wheel has a convex surface (don't ask me why) and getting the
blade to track on the "crown" of that convex surface usually requires
a little fine tuning of the blade wheel tilt.
There are all kinds of gizmos you can by to try to make your cut run
true, but if the blade doesn't ride on the "crown", then the other
things you can do won't ever allow you to dial in your saw completely.
Use a gloved hand to spin the blade as you check your adjustments.
The blade tension doesn't have to be "guitar sting tight" at this
point... but snug is nice. Once you get your blade to ride on the
crown, then close the cover back up and tension the snot out of it.
Be careful, as you can accidentally overdo it. A small blade like you
mention is fine for cutting curves, but not quite ideal for straight
cuts. Don't get me wrong... it can be done. The size of the blade
you use will mostly be determined by the ooomph of the motor. Based
on your description you may not be able to go a whole lot bigger.
Next inspect the blade for kinks and other problems. If someone used
a wood blade on metal, well then you are probably going to want to go
get a couple of sharp blades to have on hand.
Next make sure your table is perpendicular to the blade. Sounds
silly, but bandsaws (and other tools) lose their settings between
uses. Get a plastic triangle if necessary. Move the blade guards out
of the way.
Lastly, move your blade guards as close as possible to the work you
are doing.. and if you have friction blocks or roller bearings to
keep the blade from wiggling around, make sure you use them as well.
If you have friction blocks, there should only be a paper-thickness
between the friction block and the blade. Pull a dollar out of your
wallet as a thickness tester and find that allen wrench and make the
adjustment. If you are fortunate enough to have roller bearings, make
sure they are set to ride on the flat portion of the blade, and NOT
hit the teeth as the teeth go by. Again, just a paper thickness of
clearance is what your are shooting for. With roller bearings there
~should~ be a third bearing that rides on the backside of the blade
(the thin side OPPOSITE of the teeth) and this will prevent the blade
from deflecting back away from your cut.
Go ahead and plug 'er back in and give it a test. LET THE TOOL DO THE
WORK! So many folks get hasty and things don't go as well as they
Bandsaws will follow the grain... so if your cut is perpendicular to
grain, you should get good results, if the grain is ~kind~ of going in
the same direction as your cut... the blade will tend to wander.
Going extra slow during grain transitions will help.
I have read lots of articles on tuning band saws... and some folks say
that a band saw has a pre-determined "wander" that you can compensate
for by making a test cut, and then setting up a fence at a small angle
to purposefully try to correct the wander. I have tried this, but
until I started tuning from the "ground up" as I have lined out here,
my results were mixed at best.
Best of luck.
I'll 3rd the 'Yes' - and add that sharpness is also a biggie when
you're pushing the limits.
-snip what sounds like good basics-
This guy is moving too fast for my taste- but it is pretty cool,
anyway. don't look at the video description- just see if you can
guess what he's carving before you see it-
I'd definitely do all the steps listed- and probably on a new, wider,
blade. Buy the widest you can find- and only use it for re-sawing,
or thick, straight, cuts. [used to be you'd go for fewer teeth on
that re-saw blade, too, but I haven't looked at blades in 20 years, so
they are likely to have something new out there.]
Yes, they are serious. That is how a lot of people tune the saw. Setting
up a bandsaw properly takes a little time the first go around. The wheels
must be co-planer, the blade must be tensioned, the guides have to be jut
right. The biggest problem you have is the small saw. They are difficult
to get set straight. and I'm told by others, impossible for accurate cuts.
That is the difference between the $99 tool and the $699 tool.
There is a book, The Bandsaw Handbook by Mark Duginske (or like that) that
is very good explaining the setup and use of the bandsaw. Worth reading even
though it cost about 1/4 the cost of your saw. .
Oh, the 3/8" blade can be harder to tension. The wider the blade, the more
Get a pitch pipe.
Tune the 1/4 blade to a 440 A, 3/8 blade to 256 C.
Could also use a piano or electronic organ....
Or, a guitar!
With the blade positioned under moderate tension, I turn it on, get the
blade to seat, and finish tensioning it while it's turning. I "sink the
blade down" much as you sink a nut down on a bolt, without stripping
anything -- you sort of feel the maximum tightness.
IIRC,there are blade tension gauges you can buy,but,yes,the tension should
be very high.
would that be for medicinal purposes??
For the OP;
to keep a bandsaw blade from twisting,you need to keep the blade guide as
low as possible,just enough to clear the workpiece.
(and see what you're doing...)
you also cannot push too hard,forcing the work.
shouldn't the blade guide blocks RUB slightly on the blade?
A wider blade WILL help. wider blades are used for rip cuts like you appear
to be making.
sometimes called resaw blades,used to make thinner boards.
Thanks to all those that responded with advice and suggestions. I went and
picked up a 3/8 6t blade, installed it, cinched up the blade guides, and now
I'm making perfect straight cuts. Veeerryyy nice, just going to a wider
blade made a *huge* difference.
A wider blade and a bandsaw tuneup will certainly help. It is typical
there is a "drift" angle when cutting a straight line with a band saw
and you correct for that by adjusting the piece. Take your time
I put a wide blade on it, and played with it a bit. Going to the wider blade
made all the difference in the world. I think I pretty much have it tuned
the way I want it. It's not the highest quality saw out there (it is a
Ryobi, after all), but I can get it to do the job. Bandsaws are a bit
touchy, aren't they? :-)
What I wasn't sure about was how to tension - how tight is too tight, or too
loose. There is a very wide range of tension that results in a nice
guitar-like twang. It would help if the manual suggested actual pitches to
shoot for, instead of just saying it sounds like a guiter. Just going from
the low E string to the high E string is two octaves, let alone working your
way up the neck on the high E string, which is another octave and a half or
Here's a tool that will do it for you-
I imagine there is a cheaper one out there- but $419 gets you a real
fine piece of equipment.<g>
Problem with this kind of thing is that the guy who could make that
tool pay for itself can probably set by feel just fine. It is us guys
who only use the bandsaw every couple years that could benefit from
having a tool telling us what 'tight' is.
Play around- and if you're sawing on and off for a week or two you'll
probably get a feel for what your saw, your sawing speed, and your
blade like best.
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