Sunday, January 6, 2008

Tuning the Craftsman 10" Band Saw

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.

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.


Woodworker said...

Why not set the bearings against the blade? After all they're designed to turn and will hold the blade straighter.

Don said...

Two reasons from what I understand:

1. They are cheap bearings. They won't last long with constant use. Higher quality ball bearings may make this a moot point.

2. They will heat up the blade. Even with bearings there is heat generated and that gets transferred to the blade.

If you are tuned properly and have adjusted your fence or miter gauge, your blade will rarely touch the bearings. That is a good thing! You will get cleaner cuts and longer blade life. Plus the blade is tracking straight if it isn't riding the bearings.

mdhills said...

I see that you've fallen hard for the lathe. A year later, what do you think of the 10" craftsman? are you shopping for another, or do you feel you have it tuned up well for the work you're doing?


Don said...

I've found something that DRASTICALLY improves the cut from this saw. I will have a writeup on it later this week.

mdhills said...

Do you recall what adjustments you made to the lower wheel? I've found the tracking to be a bit twitchy (I can get it to track okay, but adjustments to tension throw it off), so took a look at planarity, and the two wheels are pretty far off each other.

Also, how close can you get your guide bearings? I'd read they should be about a paper-width off the sides, but the two bearings don't seem to go in that far.

Also, how much vibration do you get from your saw? (I get more than I'd expected; wasn't sure if it was normal, or if I should look at trying to balance the wheels a bit more)


Don said...

As I mentioned, it takes some fiddling to get the bottom wheel dialed in. With the saw unplugged, make an adjustment, manually rotate the wheels clockwise WITH THE BLADE ON AND TENSIONED and watch how the blade rides on the wheels. There's a lot of trial and error, but you'll quickly get a feel for how the adjustments affect the blade.

With the bearings, a piece of paper is a great gauge. If they're not going in that far, you have something preventing them from doing so. Go over the whole bearing head (top and bottom) and look. You can take the blade off for this to make it easier. The only one that should have trouble adjusting far enough is the thrust bearing, the one in the back. That's just there to keep the blade from popping off the wheels.

Unknown said...

After only about 30 inches of cutting 1.25 red oak my new Band Saw stalls even when trying to rip cut 3/4" pine at very slow feed rates. This happens in the 1st 2 inches of the cut. It stalled quite often on the oak. It does better on cross cuts. Everything seems properly adjusted though I didn't do anything to the lower wheel. Is the stock blade just garbage? It still looks good.

Don said...

If it's new I'd take it back. It should be able to do 2 inch thick oak no problem.

Make sure you're not feeding it too fast as well.

Yes, the stock blade is junk. But unless you're trying to run the wood through too fast, it should be able to handle that easily.

Anonymous said...

my 10' bandsaw that i just got used is in good shape and i adjusted the tension and tracking on the wheels fine. BUT, when i cut a peice of wood the cut veers to my right. what could this be from and can i make adjustments? thanks.

Don said...

Try tweaking the position of the blade on the upper wheel. If that doesn't help you'll have to adjust your fence to compensate for the cut angle.

Anonymous said...

should the guide bearings actually be spinning when the saw is operating or not? i adjusted the bearings as described and some spin from blade contact and some don't. should the ones that don't spin be adjusted closer?

Don said...

They only spin when the blade touches them. If you adjusted with that paper's thickness of space between the blade and the bearing, then the bearing won't always spin.

Sue in Texas said...

I saw a link to you Craftsman 10" bandsaw tuning guide on one of the woodworking boards while researching the saw before I bought it. Well, I bought it last night, but it was late, so instead of unboxing, I opted for reading your blog. I have to say, I found it all very entertaing, informative, and hopefully helpful. Along those lines i have a couple of questions: Way back in 2009 (on Jan. 5 according to the stamp) you posted "I've found something that DRASTICALLY improves the cut from this saw. I will have a writeup on it later this week." Well, I have searched high and low, and could not find a follow up, but perhaps it is buried in the body of one of the other entries, and the title of the post doesn't allude to the saw? If so, could you point me in the right direction? If not, could you share the secret with me if you remember it? On another note, I also read on another post that you had the harbor freight mini lathe. It just so happens that I recieved the same lathe for Christmas this past year, and due mostly to messy circumstances (my shop was quite messy), I only just unboxed and set it up. In fact, I was cutting a blank to do my first turn when my old bandsaw broke, leading to the purchase of the craftsman 10". Back to the lathe, I only saw a couple of posts about it, and you seemed to like it, then if really wasn't mentioned again. Did you continue to be happy with it or have any problems? I ended up reading almost the entirety of you blog and was dismayed at the end when you suddenly had to sell all of your tools and relocate. It was a year and a half before a new post appeared with you gripeing about screws (btw, I don't blame you). I truly hope you have been able to continue woodworking but just don't blog about it like you did in the past. Any pointers about the craftsman 10" and th harbor freight mini-lathe, and turning in general, would be VERY much appreciated.
Best wishes from Texas!

Don said...

I guess I never did post about the upgrade..

It was simply a high quality blade. The Timerwolf Resaw Master is an amazingly smooth blade. The Craftsman blades are absolute junk.

The HF mini lathe is my favorite starter lathe. I had one for a while. Just remember that the accessories on it are MT-1. Slightly less common than the MT-2 that most wood lathes use.

A great forum for woodturning is here:

Bob L said...

Personal experience with my new, out of the box, Craftsman 10".....
BEFORE making any adjustments... check the motor mounting bolts... mine weren't tight, so the motor drive belt tension was soft,... so it stalled even on soft pine!
Be sure your motor mount bolts are tight first!!
After, I wanted a better quality "general purpose" type of blade... replaced blade with a ⅜" 4TPI skip tooth blade from Highland Woodworking. Spoke to the guys on the phone and that's what they sent. It makes a world of difference... cuts are smooth as glass.