Changing the blade on a bandsaw can be a real pain in the Wazoo. Most of us will use the wrong blade for a job just because it takes so long to change to the right blade. But, using the correct blade for what you’re cutting will give you straighter cuts, smoother curves, a better finish. Which size blade, how many teeth per inch, and the type of tooth pattern are all important to what you’re cutting, but that topic is for another Instructable.
One final note, our Jet 14” bandsaw is for wood only. It can’t be slowed properly to cut metal of any kind.
Step 1: Let's Begin
As with all tools, turn off the saw & unplug from power. Open the wheel covers. Remove the blade guard (images one, two, three). The saw is Chinese made so everything is metric. Most machine screws involved in changing the blade have 10mm hex heads or are thumb screws. Remove the Throat plate & table pin (image four). The table pin is a press fit so pull it out with a pair of pliers. Set aside.
From the back of the saw, loosen the blade tension by lifting the horizontal lever (image five) to position shown (image six). The blade should now be slack & easy to remove from the saw. (Image seven)
Many saws don’t have this quick-release lever. In that case you must turn the long shafted vertical knob counter clock wise to lower the upper wheel & loosen the blade tension.
Remove, fold and store the blade.
Step 2: Remove the Blade
Standing at the front of the saw, grip the blade at the left and right of the wheel (image one). Pull the blade towards you off the wheels (image two). You need to clear the blade guard on the left of the saw and you need to clear the metal bracket under the table below the lower blade guides. Rotate your left hand blade around the rip fence bracket and out until the right hand blade is parallel to the saw table’s slot. Slide the blade out the slot (image three).
Step 3: Fold and Store
Looking at the pictures: Easy Peazy, right?
If this were a video, it would be easier to show than to explain with pictures.
(You’ll notice, I have put on gloves to protect my hands from the sharp teeth of the blade. But I don’t have safety glasses! You should.)
Hold the blade in both hands. Twist your left wrist down and your right wrist up. This will cause the blade to begin to fold in on itself. Continue to twist your wrists and bring your arms toward your center from your elbows. The blade should continue to naturally fold inward into the small loop shown in the last two images. (If at first you don’t succeed, try, try again.)
Use a twist tie or piece of masking tape to secure the blade.
Step 4: Clean the Wheels
Use a bristle brush and/or a brass wire brush to clean off the rubber tires. If there’s not much build up of sawdust under the blade, then a bristle brush will work fine. But sometimes that’s not enough so go to the wire brush. The end result is a smooth tire with no sawdust clinging to it. (In some instances when I’ve practiced poor “bandsaw hygiene,” I’ve needed to resort to a scraper to remove sawdust imbedded in the tires.)
After brushing, vacuum the entire machine so it’s spic & span.
Step 5: Put on the New Blade
Putting on a new blade, even if it is the same size as the blade just removed, is a little more involved than just shifting these instructions into reverse.
Unfold the new coiled blade. The pictures one through four look like I’m carefully opening up the blade – which I am. But in reality, when I uncoil a new blade, I grip one of the coils (an outer ring) and then flick the blade away from me. It springs open like magic! Once open, hold the blade with the teeth facing you. The teeth in your right hand should be facing so the hook and point of each tooth are pointing down.
Sometimes, with narrow blades, they’ll spring open and be backwards. Correct it by pressing the teeth inwards. The top of the blade should curve towards you. Keep pressing until the entire blade flips around and the teeth are facing back away from you. Now, turn the blade around and slide it through the table slot (image five).
Fit the blade around the wheels. Slide it between the upper and lower blade guides and the blade guard on the left hand side by the switch (images six through nine).
Loosen and back off the upper and lower blade guides and bearings. Center the blade on both wheels – it doesn’t have to be exact (images ten & eleven).
Go around to the back of the saw and flip the tensioning lever down to tighten the blade on the wheels.
Step 6: Tension the Blade
Blade tension is determined by the blade’s width. We’ve gone from a 1/2” blade to a 3/8” blade. Image two shows the tension spring set at 1/2”.
Using the knob above the wheel cabinet (image one) rotate the tensioning bolt clockwise or counterclockwise until the washer is in line with the 3/8” marking on the spring housing (image three).
Supposedly, you can tell if a blade is under proper tension by the tone it emits when “plucked”. For a 1/2 or 3/8” blade that would be Middle C. Well, I can’t tell Middle C from Middle Earth, so this way is best.
Step 7: Center the Blade on the Wheels
Before centering the blade, make sure it does not rub against any of the blade guides or guide bearings. The blade should spin freely.
Face the upper wheel as shown in the 3rd image. Using any disposable finger (KIDDING!) rotate the wheels clockwise (toward you) and watch where the blade tracks.
DO NOT POWER UP THE SAW TO DO THIS – NOT KIDDING!
The 3rd image shows the blade too far left on the wheel. Using the knob to the left of the tensioning spring (1st image), loosen the wing nut and turn the knob clockwise or counterclockwise while rotating the wheels and center the blade on the wheel (4th image).
When centering the blade on the upper wheel, you may notice that the blade is not centered on the lower wheel. This is because the wheels are not “co-planer”. That is, they are not aligned vertically with each other. They are not on the same plane. If the blade is not too far off center (about to fall off the wheel) we won’t worry about it.
Also, with small blades (1/4” or less) it is important that the teeth not be riding on the crown of the wheel’s tire. So it may be necessary to move the blade slightly forward (left) of center. (We want to be Democratic after all.)
After centering, re-tighten the wing nut (image two).
Step 8: Adjust the Guide Blocks and Bearings
OK, we’re getting close to being done here. We’ll set the lower guides first (images one, two, & three):
All guide blocks and bearings should still be away from the blade.
(Images one & two)
Move the lower bearing up to the blade so that it just barely touches. Tighten the thumbscrew. Rotate the blade –by hand. The blade will wobble slightly (most blade welds are not straight) and so should brush the bearing slightly as it rotates around the wheels. Adjust as needed. You don’t want the bearing spinning constantly.
Bring the guide blocks in towards the blade. Temporarily tighten the thumbscrews. Now, loosen the side thumbscrew (image three, lower screw) and adjust the blocks (knurled nut) so that they are barely behind (to the right of) the tooth gullets. Tighten that thumbscrew. Loosen the block thumbscrews again. Now bring each block up to the blade so each barely touches – or barely doesn’t touch (image seven). Tighten the thumbscrews again. Things will move, so readjust as needed.
Now the upper guides: but before we start, you must adjust the upper guide arm so that it is about 1/4” above the material you will be cutting. Each time you change material thickness, you must adjust the upper guide arm AS-WELL-AS the upper blade guides & bearing.
Setting the upper guides and bearing are the same procedure as just completed for the lower guides (images four through seven) but they’re easier to get to.
Step 9: Test
OK, now close all doors, re-insert the throat plate and the table pin. Don’t re-install the blade guard yet. Plug in the saw.
With your safety glasses on, turn on the saw. Watch the blade; see if it drifts against the bearings or drifts away from the bearings. Turn the blade adjustment knob as needed to position the blade back to where it just brushes the bearing and the gullets clear the guide blocks.
Turn off the saw. Re-install the front blade guard.
Second Prize in the
Fix & Repair Contest