I have ben watching this forum for a month or so now and am convinced that there are some mighty smart and experienced people out there that love woodworking as much as I do. Perhaps there is someone out there that can answer a question for me.
I just purchased a JET 18″ bandsaw. I intend to use it for resawing and cutting bowl blanks. Some of these blanks will be cut from green wood. So far I am pleased with it’s operation except for what seems to be an ajustment that I just can’t get right.
While cutting a bowl blank of a radius of 5″ using a 3/8″ 4tpi skip tooth blade out of a green piece of maple, the saw screeched (sp) and thumped like mad. I believe the thumping came from the belt that came with the saw, but the screech(sp)…?
I have checked and rechecked belt tension, blade tension and guide alignment but can’t find anything wrong. Also the bearings seem ok. The noise, except for the thump, does not occur during a straight cut or under “no load”.
Any other ideas? Has someone else run across the same problem? Perhaps it is a characteristic of the saw? The blade?
I appreciate any help and suggestions. Thanks in advance.
Al
Replies
Hi, Al. Your problem may be the 3/8in. blade. It's pretty wide to cut a 5in. radius piece. I would try a 1/4in. blade and see what happens. Good Luck!
Al,
First a bit of clarification, by "a bowl blank of a radius of 5" " do you mean round stock 10" in diameter? Larry's answer assumes that you are trying to cut on a curved path of 5" radius. (I think).
The screeching may be due to a slipping belt, the tires slipping on the bandsaw's wheels, the blade slipping on the tires.
I suggest a blade change also, but not for Larry's reason. The blade you're using may be binding in the wood, causing all the noise elswhere in the machine. It may not be sharp enough, or may have geometry problems not suitable for the cut you are making. Since going to low tension blades (Timberwolf) I have never had that kind of problem from my 14" saw.
Can you give a better description of the wood piece and the kind of cut you are making?
Rich
Larry AND Rich,
When I mentioned a bowl blank it is (after being cut on the band saw) 10" in diameter and 6" tall; like a cylinder.
The blade is 3/8" wide which I was told will cut a 3" diameter circle with out a problem. It is a 4 tpi skip tooth raker which was designed for cutting green wood. It is a JET blade, not the TIMBERWOLF which I heard so much about. Maybe I should have bought a 1/4" blade.
The species of the wood is maple that is fresh cut, or as they say, green. I know enough to let the saw blade do the cutting, i.e., not to force the cut. So...I am all out of ideas for reasons for the noise. I thank you both for your input.
Regards,
Al
Al,
How do you check your blade tension, and what tension are you using?
I think that the thump is slipping tires. Are they glued?
I'd try a different blade as part of the "troubleshooting" process.
Rich,
Blade tension is adjusted by means of a scale located on the machine itself. You adjust the tension by turning a wheel till the pointer lines up with a mark indicating the SIZE of the blade. Is there another way to adjust tension or measure the tension?
I don't know if the tires are glued or not. I'll check that tomorrow. Are they supposed to be glued?
Al
are you getting out the dust/chips fast enough? Wet wood will create a flurry of chips that may be binding up inside the wood causing it to freezy up. Do you have pitch on the blade? warm pitch is like glue, it maybe increasing friction inside the cut.
Al,
The tension guages on bandsaws are notoriously inaccurate. At the indicated setting, the actual tension is lower, sometimes quite a bit, due to fatigue in the spring. That's probably not a big factor in your present set up because the saw is new. Timberwolf blades are silicon swedish steel which requires a much lower tension than ordinary blades. The tension is set by a "flutter test."
For regular blades, I would not rely too much on the saw's scale. If the blade cuts better at a slightly higher setting (say the next blade size up) use it. Then get to recognize the sound of the blade at that setting, because you might eventually have to go higher on that scale to achieve the same tension as the spring fatigues. There are band tensioning guages, if you want to get really obsessive.
I think that Bill has some good suggestions.
Rich
Edited 8/4/2002 11:00:33 PM ET by Rich Rose
Thanks for your help! I did get rid of most of the noise by installing a Timberwolf blade. WHAT A DIFFERENCE!
Proper tensioning will take practice. I did purchase a book on the Bandsaw which should arrive this week sometime. Hopefully it will help.
With NO blade installed there is a squeak. I presently suspect a bad bearing on the idler wheel. The drive wheel is fine. I plan to check it out today. If necessary I will replace it with a quality bearing. I understand that those supplied with the saw are not.
I hate it when you buy a new machine and there are "bugs" in it's performance. But I am happy to say they are being worked out thanks to people like you on this forum.
Thanks again!
Al
Al,
I think that you will really like the Timberwolf blades. They are a breed apart! Follow the directions about setting them closely. And get the tension as low as possible just above the flutter point.
I find that my saw has absolutely no drift with a 1/4" blade (a resaw cut follows the fence perfectly). I almost don't need the blade guides. The blade just cuts maple like it is soft pine, without wandering or complaining.
Good luck,
Rich
Rich,
I followed the instructions that came with the Timberwolf blades for setting tension. WOW! What a difference! All the noise went away. Funny how a blade will create havoc with a machine...and a new blade at that!
Those blades are cuttin son-of-a-guns!
I wish I had gotten a bandsaw sooner. What a time saver and pleasure to use!
Another question. The book says to lubricate the blades with Pam of something of the sort. Do you recommend that too?
Regards,
Al
Al. I do exactly as the Timberwolf people say to do. If they recommend it, it's good! Great porduct. They're really nice to talk to on the phone.
It baffles how a manufacturer can ship an excellent piece of equipment and include some defective, low cost component that is almost an after thought and which renders the operation almost useless. I've had the same problem with blades, v-belts, miter guages, t-slot riders, fences, covers, etc.
George Iturra of Jacksonville FL sells a blade tension measuring device about 1/2 the price of the starrett. He has an 800# and is very knowledgable about bandsaws. He makes many after-market products and is a pleasure to deal with.
Can you give me his #. I'd like to talk to him.
Thanks.
Al
call 800 directorya ssistaznce -- Iturra Woodworking, In think.
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