Replies

1. 
   BrentS | Mar 08, 2005 12:40am | #1

   Check 2 things: are your bottom guides parrelel with the top guides  .......... have you adjusted the blade tension properly? On alot of saws the tension adjustment scale is just a starting point,usually you need more tension than the scale reads.I'm assuming that you have correctly spaced the guide blocks.

1. 
   HWG | Mar 08, 2005 12:47am | #2

   UMMM,

   Be sure you have a high quality blade.  One sign of poor quality if a rough cut, which you describe.  Another is a poor weld, which could be what do see with each revolution.  There has been much discussion of bandsaw blades on this forum -- do a search.  Timberwolf and Wood Slicer seem to be the most recommended, but there are others that are also good.

   Woody 

1. 
   CherryDust | Mar 08, 2005 01:02am | #3

   The blade I bought was an Olson All Pro. Are these not good?

1. 
   HWG | Mar 08, 2005 01:09am | #4

   Sorry, I have not used them. I will defer to others. 

2. 
   BG | Mar 08, 2005 01:21am | #6

   Ummm,
   I've been using an Olson for a few months, they seem fine....and if you're going to mess up, might as well be with a less expensive blade.
   What kind of BS did you purchase?
   Have you run the blade without the blocks and bearing in place...does it run in the center of the tire? 

2. 
   BARRISTERBUILDER | Mar 08, 2005 01:15am | #5

   Did you check that the top and bottom wheels are in the same vertcal plane?

3. 
   mike4244 | Mar 08, 2005 01:55am | #7

   In addition to the other posts, check the weld on the blade. It should be smooth on each side. If you hear any clicking noises the weld might need filing.I imagine you have cool blocks, either round or square, as an experiment ,replace the cool blocks with a dowel or square piece of wood. Let the wood actually touch the blade. Run the saw a minute or two. If the blade does not jump to the left, your cool blocks are not adjusted correctly. The cool blocks can almost touch the part of the blade that has no teeth. Make sure the roller guide does not touch the back of the blade until you are sawing. Set this guide about the thickness of typing paper behind the blade.

   An out of round wheel could also cause this problem, this is a factory fix.If the wheel is unbalanced it can cause vibration, out of round will too.You can balance a wheel with automotive wheel weights, or by drilling the webs on the wheel.

   mike

4. 
   ktpowell54 | Mar 08, 2005 02:37am | #8

   from my experience, the best thing I did was replace the old V-belt that generally comes with all belt driven machinery with a linked-belt. the old V-belts have was is called shape "memory" and they induce a lot of harmonic vibration. I watched a large wrench walk off my delta 14" bandsaw's stand before replacing the belt. I had done all the fixes mentioned in countless articles, but it was installing the linked-belt that made my 20 year old saw stop vibration. I ran the saw for two hours with a nickle standing on edge on the bandsaw's table. These belts are expensive...about $6/ft, but they work! I got mine from Grainger under the brand PowerTwist.

   Hope this helps.

   -ken

5. 
   Michmesquite | Mar 08, 2005 03:38am | #9

   First of all, Olson blades are just fine. They have been sharper and sharper longer than the TW blades I have bought.

   Second, your guides should be set just slightly behind the tooth, but not in the part of the tooth making up the tooth offset.

   Third, if your guides are set up correctly with the smallest of gaps between the guides and blade, you should not see any delta in the blade travel. Make sure your guides are set to the "Dollar Bill" tightness.

   Good luck with your new saw.

   _________________________________

   Michael in San Jose

   "In all affairs it's a healthy thing now and then to hang a question mark on the things you have long taken for granted." Bertrand Russell 

1. 
   CherryDust | Mar 08, 2005 03:53am | #10

   So it sounds like the rough surface of the cut and the blade moving to the left are not normal bandsaw behavior. Looks like I have a lot of troubleshooting to do.

   Thanks everyone.

1. 
   highfigh | Mar 08, 2005 04:07am | #11

   If you have a straightedge that will fit under the raised guide, place it along the blade at the weld. If the weld isn't straight or there is a kink in the blade someplace, you'll see the wavering.
   "I cut this piece four times and it's still too short."

2. 
   Michmesquite | Mar 08, 2005 04:50am | #12

   You will never get a glue line rip with a bandsaw. Since the guides are set with roughly .005-.008" slop side to side, you will always have that roughness present.

   I don't know what brand saw you have, but I can crank my MM16 up to nearly 30k psi with my Lennox 1" Trimaster and get a very nice cut, but is it still a lot worse than the cut I get from my worst TS blade and I wouldn't use the finish as a glueable surface. But then I can and have resawn 11" Maple boards at the rate of about 12"/min.

   Although fairly rare, bad butt joint welds can cause a problem, but the problem is usually easily traced to the weld by rotating the blade by hand. Since all of the major brands machine cut and weld their bands, the chances of a bad weld from a name brand is slight - but it does happen._________________________________

   Michael in San Jose

   "In all affairs it's a healthy thing now and then to hang a question mark on the things you have long taken for granted." Bertrand Russell 

6. 
   SawdustSteve | Mar 08, 2005 05:56pm | #13

   Let's tackle the main problem... 'After tweaking the drive belt for quite a while, I finally have it so the saw isn't vibrating too much.'
   There should not be any vibration, just a smooth hummm of the machine. It is VERY rare that a motor itself will cause vibrations. Start by CAREFULLY checking the setscrew on the two pullys. Make sure they are properly seated and alligned to each other. The drivebelt should be tight but not so tight that it puts a strain on the bearings. Take the blade off the saw. Give the top wheel a good spin by hand and let coast to a stop. Mark the 'top dead center' (TDC) with a magic marker. Repeat this process several times. If the top wheel is properly balanced, you SHOULD NOT see the same spot come to TDC. Take off the drive belt and do the same with the lower wheel. MOST vibrations come from an out of balance wheel. Take the blade and lay it, teeth up, on a smooth flat surface. Check the blade for any kinks. Since you state that there is still a 'jump' in the second blade, perhaps you're kinking the blade when placing it on your machine... a common occurance with new bandsaw users. It is possible that a 'run' of blades were all welded poorly. Run your fingers over the weld spot and check it for lumps. You say the blade jumps to the left, so check the right side bery carefully for weld lumps. If you find this condition, carefully file or stone the lump. I use Olsen blades and find them very good. I have several different widths and tooth configurations. Last, what make/model saw do you have? SawdustSteve

1. 
   CherryDust | Mar 08, 2005 06:47pm | #14

   I spent a lot of time trouble-shooting the saw last night. It now passes the nickel test so I think I have solved the vibration issue.

   However, I tracked the blade problem to the top tire. There is a flat spot on the tire that is causing it to move. I measured the deflection with a dial caliper and it seems the blade moves left-to-right approximately 0.04" per revolution after tensioning the blade (0.02 per side). I took the tire off and verified it isn't the wheel but is actually the tire. I'll be contacting Delta today to see if they'll send me a replacement.

   Thanks for all the good info