The Forestry Forum

I know alot of you run belted bandwheels, and wondering what is an acceptable amount of runout or out of round? I tried the orange inserts & couldn't get the results I wanted so replace them with b belts but still have alot of blade vibration due to the tire runout. Ay ifo is appreciated.

There are two kinds of blade vibration.  If it is truly out-of-round or unbalanced wheels, that might be a problem.  But, if you are judging by the vibration of the band then you might just be looking at harmonics from the engine and other moving parts.  That is perfectly normal. (within reason)

The span of band between the top of the wheels is the most vulnerable because there is a long stretch of open band.  Woodmizer puts a dampening device (I replaced it with a piece of wood) that contacts the band if it starts gyrating too much.   The bottom span is already dampened by the blade in the log and the guides.  It will still vibrate some between the guide and the power bandwheel.  That vibration is more, or less, depending upon the distance of the guide from the wheel. You can control it a bit with band tension.

If the entire saw is vibrating, it usually means that something is stuck in the "V" groove of the bandwheel, throwing it out of balance.  This might be packed sawdust or even a piece of broken belt.  If this is the case, you will not only feel the vibration, but will hear a roar, like an eighteen wheeler on a macadam road.

All mills will have a little band vibration. 

I think any wheel running belts, no matter whether tight or loose, is going to have a huge amount of runout.  Just for kicks I just now checked the tight belt on my TK.  It was running + or - .012 pretty consistent except at one spot where it measured +.022.  It saws smooth as butter.  I think the manufactures don't worry about vibrations as they tune em out by using down pressure on the guide rollers. 

I've set up a few shop bandsaws from 14" to 32".  I've found to get them running smooth the runout needs to be less than .003.  Normal procedure is to cut a crown on a rubber band while installed.  I've never ever seen one of these saws with pressure exerted by the guides.

I have found other things will cause small vibrations.  Blades, tension, motors, and a few that I never identified.  My Delta 20" is powered by a 3 phase motor and a VFD for variable speed.  It's a really smooth running saw but I found when varying the speed there are a couple of places where vibrations increase.  Only a cycle or two makes a difference.

I would try down pressure with your guides and see if the vibration goes away.  Let us know what you find.

My vibration or oscillation is directly due to the runout of the belts in the wheels. I originally had the orange rubber inserts but they were very out of round also. I made a router setup to true the inserts on the wheel and that removed all vibration. trimming the inserts also cut the crown off of the inserts so it was hard to track the blade so I thought I would try belts instead.I have alot off runout in the belts now. I haven't tried sawing with it because I am running a timberwolf blade & trying to tension it by the flutter method witch is hard to do with the blade vibrating.I am new to all this & dont really now what to expect.I just want to get everything right before I start trying to cut.