WARNING!!!
All operarions discussed in this article were done with the saw turned off and unplugged. I **HIGHLY** recommend you do the same. I cannot be responsible for your failure to unplug the thing when sticking your hands around its sharp blade and spinning wheels!!!
Ok, you got the 10" Craftsman band saw for Christmas. The manual is pretty much a joke, and all the stuff online is for 14" Deltas, Grizzlys, Jets, etc. What do you do?
I watched a buttload of videos, read many many writeups on band saw care, checked books out of the library, etc. After much playing with techniques on my band saw, I feel I can share what worked.
TENSION
The Sears Craftsman 10" band saw, model 21400
, oddly enough does not come with a tension gauge. That makes accurately setting the blade tension not only difficult, but possibly dangerous! After some research, and various "techniques" used by other owners, here's what I settled on.
- Deflection
The blade of the 10" model 21400 band saw should deflect 1/4" at the center of the exposed area with the guide fully raised using "pinky finger" pressure.
To measure that, set a 2" thick block of wood on the table. Set your try square on top of that with the end of the ruler just behind and parallel with the blade. Use your pinky to press on the flat of the blade along the ruler. If you can't move it 1/4", it's too tight. If it goes further, it's too loose. Adjust with the knob at the very top of the saw.
Note that this measurement is only accurate for the stock blade that comes with the saw. Different blades may need more or less tension.
Guide Bearings

One of the great features of this saw is that it comes stock with guide bearings instead of blocks. Which is superior is open to debate, but I happen to be a fan of ball bearings wherever possible.
Using one of the two allen wrenches that came with your saw (or one from any SAE kit) loosen both bearings. Not much, just enough that they will move from side to side. On the top bearings there are little mushroom pins that stick out of the sides, making it easy to push or pull the bearing as needed.
Stick a dollar bill between the bearing and the blade, then gently push the bearing against the dollar bill just hard enough to hold the dollar in place. Hold the bearing with one hand and tighten the allen screw with the other. Pull the dollar bill out.
Repeat for the other bearing.

Open the cabinets and spin the wheels and make sure the blade doesn't run against either bearing. Readjust if necessary. You want a bit of air gap between the blade and bearing.
There is a pair of bearings on the bottom as well, and they are more difficult to access, though you still need to adjust them. These oddly don't have the mushroom head pins, making it a 3 handed job. Do your best.
While you're adjusting them, make sure the bearings will never touch the teeth of the blade. They should only ride on the flat side of the blade. Directly behind the bearings are allen head set screws that will move the bearings forward or back as needed.
Blade Tracking
Open the cabinets and look where the blade rides on the tires. It should be pretty

close to dead center. If it isn't, the adjustment method changes depending on upper wheel or lower wheel.
- Upper Wheel:
This one is easy. There's a black knob directly behind the upper wheel on the outside of the cabinet. Loosen the locknut (wing shaped plastic spinner under the knob) and turn the adjusting knob. Small adjustments make a big difference, so turn it 1/4 turn, then spin the wheels by hand in the direction they normally turn and watch where the blade moves to. It can take many turns of the wheels to get the blade to settle, so don't stop until the blade stops moving. Tighten the locknut/wing when you're happy with its position.
- Lower Wheel:

The lower wheel is trickier. There is a steel shaft that sticks out the back of the cabinet with 4 adjusting screws with locknuts. No handy knobs or wings here. And four adjustments that influence each other keep it interesting. Loosen all four locknuts, then turn the adjusting screws a tiny amount and watch what affect each has on the blade tracking. Then adjust until the blade tracks centered on the tire and tighten the locknuts.
With these adjustments done, you will be surprised how much better the blade cuts. I took mine out of the box, put the table on, guesstensioned the blade, and made some cuts. Ugh. Better than some I've seen, but I have no idea what kind of state of tune they were in.
One thing that I find really irritating about this saw is the thrust bearing position. Adjusted to its furthest forward position, it is still far enough back that the teeth of the blade will touch the side bearings. This is a bad thing. Especially since the stock blade is a 3/8" blade. What if I go with a 1/8" blade?
This final photo shows a cut made before my adjustments (left piece), and one made after. You can see the drastic difference between them!

Both cuts were made with a scrap piece of pine. I believe I can get a smoother cut with a different blade, but this one works quite well as it is. Not bad at all in fact.
I didn't discuss setting the table in this article because hopefully you've already squared it before you've gotten to the cut quality point. If not, get a try square and adjust per the manual.