i got the flutters

laffs · January 10, 2010, 09:53:51 PM

i have timber harvester :( when the guide is all the way in the blade flutters. if i move the guide out to about 16 inches it comes out of it ... anyone know why this might happen

Magicman · January 10, 2010, 10:19:07 PM

Not familiar with a TH, but my first thought is that the blade guide may not be properly adjusted. Maybe there is more/less tension exerted as the guide moves out or in. Also, are the guide bearings turning freely?

LOGDOG · January 10, 2010, 10:36:34 PM

laffs,

It sounds like your blade guide is climbing as it travels inward. The narrower you go the higher it climbs and thus you have less tension. On most of our WoodMizers we have rollers that the blade guide arm rides on. There's an eccentric cam bearing that is used to adjust the travel of the blade guide arm. Do you have that type of system guiding your arm? Maybe a picture of your mechanism?

LOGDOG

pigman · January 10, 2010, 10:54:59 PM

There is a vibration somewhere. When the guide is moved in to a certain point the natural frequency of vibration is reached on the section of blade between the guides. :-\ Or maybe I'm just guessing. ;D

Tom · January 10, 2010, 11:00:21 PM

I think Pigman is onto it. That vibration isn't always a bad thing, but it could be showing that the blade could use a little more tension. It's harmonics.

Usually when the blade is unsupported for 15 or 20 inches on any mill, there will be a little flutter somewhere. I'm not surprised that the flutter stops as you shorten the length of unsuported blade, but a little surprised that you don't pick up some flutter behind the guide as the unsupported portion between the guide and the bandwheel increases.

Try a little more tension on the band

LOGDOG · January 10, 2010, 11:07:52 PM

Quote from: laffs on January 10, 2010, 09:53:51 PM
i have timber harvester :( when the guide is all the way in the blade flutters. if i move the guide out to about 16 inches it comes out of it ... anyone know why this might happen

Did I misunderstand when he said "all the way 'in' "? I was thinking that would be with the blade guides closest together. To me all the way "out" would mean the blade guides are at their farthest distance apart.

laffs ... where is the flutter? Between the blade guides or on the outside of the the moveable blade guide, towards the bandwheel?

LOGDOG

backwoods sawyer · January 10, 2010, 11:36:35 PM

I would look at the guide adjustments and bearings, if the guide is fluttering.

Chuck White · January 11, 2010, 05:38:33 AM

I would go along with BW Sawyer on this one!

When the blade guide wheels are close together and the blade appears to have a flutter, it seems to me that the 2 blade guide wheels are not exactly in line with each other. One of the wheels may be level with the mill (bed), but the other has to be tilted at least a little, up or down!

Do some measuring from the back and front of each wheel to the bunk!

york · January 11, 2010, 07:19:31 AM

very poor design-have it and hate it-need to clean the vee track on the guide arm and clean the little vee guide wheels and adjust-should run parallel to the bunks-have fun.

LOGDOG · January 11, 2010, 09:26:44 AM

That's what I was thinking york.

LOGDOG

laffs · January 11, 2010, 12:43:58 PM

thanks for all the input. the flutter is between the wheels when they are closed when they open it goes away. ive checked for play and pitch buildup. as far as vibration,ive had this mill going on4 yrs and ive had to change almost every bearing pulleys werent lined up,they went out of business while it was still under warranty, so no tech support. oh plus some of the hydralics leaked. so with all the maintinance and new parts not to mention the ones i cut off with the blades and had to reweld (part of the learning curve)im kinda dissappointed. maybe they built it on a friday? so anywayil have to recheck the alignment of the guide wheels and buy a tensioner. maybe someday il make some profit.

LOGDOG · January 11, 2010, 03:34:51 PM

Iaffs,

Here's an idea. Move the saw head forward so that the blade is located directly over one of the bed rails. (Make sure you're bed rails are level first.) Then take a large framing square or tape measure and measure from the bottom of the blade to the top of the bed rail. First do it with the blade guide closed and then move it outward (wider between the guides) and measure from the bottom of the blade to the top of the bed rail as you open the blade guide wider. I'm guessing that the measurement from the bottom of the blade to the top of the bed rail will be greater when your guides are close together than when they are spread farthest apart. Measure once and let's see.

LOGDOG