Help with a craftsman 10" band saw.

[RacerRusty]

I'm not sure if this post is in the correct area of the board or not but here goes.

I'm hoping there is someone here that works with these types of machines professionally, or is enough of an enthusiastic hobbyist that they can help Me out.

I have come in possession of a Sears, Craftsman 10" band saw for an amazingly good price. Free!! Now I don't know the history of this tool but I'm guessing that it was in at least one yard sale because there is a round sticker on the side with a hand written $10 on it. But I think I understand why I ended up getting it for free. I can't make the thing work properly.

The machine appears to be in decent condition. Only the slightest hint of a little surface layer rust on the table. No rust anywhere else I could see. It is a table top modal. The blade rides over three wheels inside the body. The blade had a small amount of surface rust only on the exposed section. No obvious bends, kinks or repairs. No missing teeth. It does power on and run. I have the saw only, no books, no accessories.

Now here is the problem. The instant wood touches the blade, the blade starts turning to the right and then eventually pops off the wheels. I have even tried turning the wood to keep up with the blade wander and it still pops off. (Man, that is one scarry sound when it does too!!)

My test board has been (Shocker ) a scrap piece of PWD block 1/4" thick.

Steps I have taken attempting to fix it:

I have adjusted the blade tension from so loose the blade barely moves to so tight the motor can't move the blade and every level in between. I have adjusted the guides (Upper and lower) from spaced two playing cards away from the blade to constantly rubbing and the same with the thrust bearings (Correct name for those parts?).

Nothing I have done has had any effect on the problem that I could see.

I have messed with this saw for four months now trying ever combination of blade tension, guide spacing and bearing spacing I can dream up, with no success.

Does anyone here have any experience with this sort of thing? Any and all suggestions would be GREATLY appreciated.

Thanks,
Rusty

[Doug-in-the-woods]

One problem is it's Craftsman. Not real good power tools.
Sounds like the wheels are warped or out of adjustment.
All the wheels must be in line with each other.
The tires could also be bad. After each use one must loosen the blade tension so the tires don't take a SET.
I would check the alignment first, check for worn bearings etc.
good luck your going to need it.

[RacerRusty]

Doug,

Thanks for the response. The bearings seemed ok to Me, I tried making them wobble by hand before. I forgot to mention that in the list of things I checked, sorry. I will check them for warpage, but I have no idea how to properly check them for alinement. Your response makes Me think the "tires" may definitely be part of the problem. They have definite "groves" in them, especially the top wheel. (The tension adjuster) The groves are very distinctive where the back of the blade rides. (I'm going to show My ignorance here) I thought the groves where there on purpose to "lock" the back of the blade into proper position on the wheels. If I understand your response correctly, I was looking at, part of the problem at least, the whole time and mistaking a flaw for intentional design.

Ooops.

[Stan Pope]

Speaking not as an expert on band saws but, instead, from the logic of the process, here are some observations:
1. The blade movement in the guides is normal under no load.
2. Under load, the blade twists between the guides.

My understanding of the guides is that they are supposed to help the blade retain orientation and location. To twist, the blade must be coming out of the guide, toward the workpiece.

It sounds as though the blade is allowing itself to be deflected by the workpiece instead of cutting into the workpiece.

Is it possible that the blade is either very dull or has lost its "set". The loss of set appears assymetric. So could the depth of the blade guide be (or have been) too deep, allowing it to affect the set of the teeth?

The twisting of the blade also suggests that the blade too easily escapes the blade guides. If the front edge of the guides has been affected by the teeth, then a small amount of twist can cause vibration and unseating of the blade and, eventually cascading twist.

So, I'd look most closely at (1) the condition of the blade guides, and (2) the "set" of the teeth. (Teeth in a saw blade usually protrude slightly sideways, alternating the direction on successive teeth. Either the angle or the distance of that protrusion, I don't know which, is called the "set" and causes the kerf to be slightly larger than the thickness of the blade.)

[RacerRusty]

Stan,

Thanks. I will give the blade and guides a good look over In the morning when the sun comes up.

I'm guessing that the area of the guides facing the blade should be flat to the blade. If they are not should I grind then flat?

[Doug-in-the-woods]

The guides should be flat and adjusted the thickness of a slip of paper from the blade
If the tires have groves then I would start there. Replace the tires and maybe locate an owners manuel to show wheel adjustment and alignment.
To check alignment place a long straight edge (yard stick or ?) across the face of two wheels and the straight edge must be touching at each end (contacting both wheels at 2 places per wheel.
I have a book on bandsaws, will try and locate to scan some pics.

[blcrow33]

I also got a Craftsman band saw second hand that was all out of adjustment. I went to Sears.com and ordered the manual for it. Then I followed all the adjustments in the manual and now the band saw works great. I would suggest getting the manual and starting there with the adjustments.

[MaxV]

I didn't see any mention of the blade size. Any blade under 1/4" will tend to wander except in very thin wood. Also, dull blades will wander.

So, I suggest (many of these have already been stated in this thread).

1. Sharp blade at least 1/4 inch wide - we use 1/2 inch blades for most cuts, and 1/4" only when making curves in thinner wood.

2. Skip tooth blades are best - fine tooth blades cut far too slowly.

3. Make sure the blades run in the center of the two pullys.

4. Tighten blade until no left to right wobble/wiggle.

5. Guides (two metal pieces that sit on each side of the blade) should sit just behind the teeth, a paper width from the blade (don't set them into the teeth, or the blade will get dull quickly). You like have two sets, one above and one below.

6. Set guide wheel(s) a paper width from back of blade.

7. Drop the upper guide assembly to sit just above the wood being cut.

8. Don't feed the wood faster than the blade can cut it.

Hope this helps.

[RacerRusty]

Doug,

I miss informed you. Sorry about that. My initial information was based off touch. I checked again, visually this time. all three wheels are PLASTIC. They are grooved. (Think H shaped PWD wheel treads.) The rubber tires ride in the valley of the H. It was the edges of the H I was feeling and thinking where groves. The tires appear to be OK on all three wheels. The bearings appear solid with no wobble when I attempt to deflect them side to side. (Although the plastic wheels will deflect with very little excess sideways pressure. ) None of the wheels appear to be warped and alignment appears to be good as best I could check it considering the wheels are plastic and NOT well finished on the outside edges. With the blade mounted and turned by hand it appears to ride steady in the same location on all three wheels. That being said if I try to position the blade to ride anywhere on the wheels (Along the front or back edge of the tires) the blade migrates back to the original location and then stay's there. (Upper and lower blade guides completely removed for this test). And thank you VERY much for your offer of pics from your book. All help is GREATLY appreciated.

Stan,

The guides surfaces appear to be flat and square to the guides cylinder wall. (The guides are round pins) The blade however has no "Set" that I could see even using a 20X magnifying glass. By "Set" I am guessing you mean the teeth being flared out to the sides of the blade slightly, the direction alternating every other tooth, creating a small valley. I can remember My Father teaching Me to set a needle in the "valley" of hand saw teeth and letting it slide from the handle to the end, as a quick method of finding bent or out of alignment teeth on the saw. The teeth appear to be lined up in a perfectly straight line. Feeling the blade however offers something interesting. As you know the blade is a steel band/circle. When I ran My thumb along the inside of the circle traveling against the teeth (Simulating pressing My thumb against the left side of the blade if it was in the saw and the saw was running) I could feel the lobes of the teeth as My thumb slide past them but there was no sensation of grab from the tooth points. When I repeated this, rubbing My thumb along the outside of the blade (the right side if the blade was mounted in the saw) I could feel the saw teeth grabbing at My thumb. I had the distinct feeling that if I pressed to hard against the blade the tooth points would start cutting skin. I find this VERY interesting, considering that the blade twists to the right (Toward the outside of the blade) when wood touches the blade. For your information I ran the saw again and watched very carefully the sequence of events. When the saw starts cutting the blade twists and pulls itself out of the guides. I think this is what makes it pop off the wheels. (It still makes Me jump when that blade pops off, even when I'm expecting it. )

blcrow,

Thanks, an Owner's Manual is now on order.


MaxV,

The blade appears to be just a hair shy of 1/4" as measured from the back edge of the blade to the tips of the teeth. I do not know if it is a "Skip tooth" blade or not. The teeth are definitely not what I would call fine toothed at all. The tooth spacing along the blade is exactly 1/4" tip to tip. Based on My finger slide, recommendations of insuring the blade is sharp and your blade size recommendation, I think I'm going to purchase a new 1/2" blade and give that a try. Based on your recommendation I will try to insure it is a "skip tooth" blade. There are three pulley's on this model not two and the blade rides (turned by hand because I'm NOT brave enough to run this thing without the cover in place and screwed down TIGHT ) just a tad to the rear of center. All your other recommendations will be followed closely as soon as I get the new blade and get it mounted.

Thank you all VERY VERY much.

Rusty

[Stan Pope]

THen I suspect that the blade dullness will be an issue ... but later ... after you resolve the current problem of "keeping it on the wheels!"

[Doug-in-the-woods]

If the wheels have groves then you need to replace the tires and / or wheels.
The tires should be smooth no groves.
The set on the blades could be a problem but correct the obvious first =the tires.
If the wheels are aligned then the tires would be my next correction.
On blades, I find the Olsen pro max to perform better than the Timber wolf blades.
Both quality blades but the Olson Pro max gets mty vote - 10+years working with bandsaw, 20+ woodworking.