The Forestry Forum

General Forestry => Sawmills and Milling => Topic started by: 123maxbars on December 26, 2011, 07:50:53 PM

Title: Found something odd on my LT35 today,
Post by: 123maxbars on December 26, 2011, 07:50:53 PM
Well for the past few weeks i have been having issues sawing on my LT35 (LT28 then upgraded and had no issues sawing on the LT28). Today while putting on a new blade I noticed a small block of wood mounted inside the housing that the blade goes into. The wood was directly below the exhaust on the kohler engine but was inside where the blade tracks. The only way to notice the wood was to bend down and look up where the blade tracks, it was not visible with just the doors open.  I thought at first it was scrap that got lodged in there somehow. After looking at it further it was screwed in and had two screws outside of the housing that pretty much had it bolted into the frame. I noticed it was black on the bottom where the blade had been rubbing up against it constantly. I unscrewed the screws and took the wood out. I then cut about 100 feet of pine and had no trouble in my sawing like I had been having leading up to this find. Right now I'm not sure why that block of wood (probably 1in thick and 4in wide) was bolted in there like that, but it apparently was having a huge effect on my sawing. Anyone else ever see this on their woodmizer? Maybe it was attached for shipping purposes or something?
Title: Re: Found something odd on my LT35 today,
Post by: POSTON WIDEHEAD on December 26, 2011, 08:35:58 PM
Good post. Makes me wonder now???
Title: Re: Found something odd on my LT35 today,
Post by: caveman on December 26, 2011, 08:47:13 PM
Our lt 28 has the same block of wood.  I assumed that it was there for a reason but I do not remember reading about it in the manual.  The mill cuts well.  Caveman
Title: Re: Found something odd on my LT35 today,
Post by: zopi on December 26, 2011, 08:47:42 PM
I believe it is there to keep the blade from smacking the housing if it rides off...sacrificial piece..I recall reading something about that on this very forum a few yrs back...
Title: Re: Found something odd on my LT35 today,
Post by: WDH on December 26, 2011, 08:51:14 PM
There is a similar block of wood on my LT15.
Title: Re: Found something odd on my LT35 today,
Post by: Magicman on December 26, 2011, 09:21:35 PM
If I am following you, it sounds like an anti-vibration "damper" between the blade wheels.  This keeps the blade from oscillating and prevents premature metal fatigue.

Post a picture or maybe Marty Parsons will pick this up.
Title: Re: Found something odd on my LT35 today,
Post by: 123maxbars on December 26, 2011, 09:28:04 PM
I appreciate the replies. This block of wood was causing my blade not to run at the fastest speed possible. The blade was rubbing against the wood which I think caused my sawing problems I have had lately. I think my blade was running slow due to rubbing on the wood causing my cuts to be wavy and in accurate. Sawed for three hours today after removing the object and the LT35 saws perfectly. 
Title: Re: Found something odd on my LT35 today,
Post by: Magicman on December 26, 2011, 09:41:16 PM
I have never seen an LT35, but if it is what I described, it should not contact the blade, but should be adjusted about 1/16th inch away from the stopped blade.  It should only contact the blade to stop any blade oscillation.
Title: Re: Found something odd on my LT35 today,
Post by: Magicman on December 26, 2011, 09:42:34 PM
I see that Magic Smoke is on here.  Maybe he will pick it up.
Title: Re: Found something odd on my LT35 today,
Post by: Magic Smoke on December 26, 2011, 09:44:05 PM
You are exactly right Magicman.
Title: Re: Found something odd on my LT35 today,
Post by: Magic Smoke on December 26, 2011, 09:45:47 PM
Although I think the wooden blocks are fixed now, as compared to the set screws used on some mills.
Title: Re: Found something odd on my LT35 today,
Post by: Magicman on December 26, 2011, 10:01:23 PM
123maxbars, I would trim or adjust that block so that the tightened blade is about 1/16' from the block.  It is there to prevent premature blade failure.
Title: Re: Found something odd on my LT35 today,
Post by: Bill Gaiche on December 26, 2011, 10:13:50 PM
I agree. I added one from oak to mine. Its so the blade does not bounce up and down when running. When blade is tight there should be at least 1/16" clearense. There is no reason the block would make the mill cut bad or pull down the engine if the clearense is there. bg
Title: Re: Found something odd on my LT35 today,
Post by: Chuck White on December 26, 2011, 10:20:33 PM
It operates on the same principle as the plastic/nylon bearing in the bottom of the blade housing on the LT40's.

Follow the suggestions already given and just sand a little bit of it off, so that you have between 1/16 - 1/8" clearance when the blade is tightened to your desired tension.

Title: Re: Found something odd on my LT35 today,
Post by: pineywoods on December 26, 2011, 10:59:53 PM
123, that block of wood serves a very critical purpose. It's there to dampen out blade flutter. without it, you will break blades like crazy, as well as some other not-so-desireable things. If the blade has been rubbing hard on it, you have some other more serious problem.
Title: Re: Found something odd on my LT35 today,
Post by: ladylake on December 27, 2011, 07:14:08 AM

My B20 doesn't have a wood block to stop flutter and I have lots of blades sharpened down to 1" wide without breaking but WM blades a little longer and running loose belts which might cause more flutter.   Steve
Title: Re: Found something odd on my LT35 today,
Post by: r.man on December 27, 2011, 08:08:02 AM
I do wonder why this problem happened so recently on a used saw that had been running well. Has the block moved or has the blade managed to shift due to a wheel bearing or something in the main adjustment. Moving the block and fixing the problem points you in the right direction but I expect it fixed the symptom not the problem.
Title: Re: Found something odd on my LT35 today,
Post by: Magicman on December 27, 2011, 08:35:13 AM
There is nothing to adjust where this block is located.  If it was a bearing problem, the blade would not properly track or stay on.

Sometimes mill/blade vibration is caused by simple things like a piece of bark, etc. tightly wedged into a blade guide groove.  Always check and clean these grooves at blade changes.
Title: Re: Found something odd on my LT35 today,
Post by: YellowHammer on December 27, 2011, 01:59:26 PM
I checked my LT-40, it has a threaded metal stud that is about a quarter inch from the blade, no wooden block or piece of plastic.  I may replace it with a wooden block because I don't like the idea of my blade bouncing into a metal stud to stop vibration.  I am guessing I should also adjust the stud closer to the blade, anyway.  Any thoughts? 

Thanks,
YH
(https://forestryforum.com/gallery/albums/userpics/21488/LT-_40_Guide.JPG)
Title: Re: Found something odd on my LT35 today,
Post by: Chuck White on December 27, 2011, 03:37:19 PM
Quote from: YellowHammer on December 27, 2011, 01:59:26 PM
I checked my LT-40, it has a threaded metal stud that is about a quarter inch from the blade, no wooden block or piece of plastic.  I may replace it with a wooden block because I don't like the idea of my blade bouncing into a metal stud to stop vibration.  I am guessing I should also adjust the stud closer to the blade, anyway.  Any thoughts? 

Thanks,
YH


YH, check it out, that stud isn't metal, it's nylon!

It should be adjusted to between 1/16 & 1/8 inch.

Chuck
Title: Re: Found something odd on my LT35 today,
Post by: petefrom bearswamp on December 27, 2011, 06:58:17 PM
Chuck,
Looks like metal on my lt40, and thought so on my old mill (which is yours now.)
I am going to check this tomorrow if it doesn't snow too hard.Weather is calling for snow all week.
Oh well we have dodged the bullet so far.
My manual says 1/16"
Pete
Title: Re: Found something odd on my LT35 today,
Post by: YellowHammer on December 27, 2011, 09:08:47 PM
I just pulled it from the saw to check it a couple minutes ago, its definately metal, I checked it with a file and a magnet.  I wonder if I shouldn't replace it with a nylon one, that sounds like a good idea.... 
YH
Title: Re: Found something odd on my LT35 today,
Post by: MartyParsons on December 27, 2011, 09:46:46 PM
Hello,
The picture is a 3/8 bolt or better yet allen bolt with lock nut. Not ever seen a plastic one, dont think it would last very long. I am not sure why the first post that the blade had been hitting or rubbing the wood. It should be in there, it is not something new. They have been using the wood for some time. LT15, LT28 and LT35 The other mills use the metal bolts. The LT70 is from the top.
The early mills had a bearing running on the band in the center top.
I have seen these bolts good as new and some are gone like rubbed / ground off.
Hope this helps.

Marty
Title: Re: Found something odd on my LT35 today,
Post by: Bill Gaiche on December 27, 2011, 09:52:23 PM
I would say replace metal stud with a nylon/plastic stud. Maybe a brass one would work or aluminum but not sure. Trial only would you know for sure. The steel stud would cause gaulding in my opion and could damage a blade over time. bg
Title: Re: Found something odd on my LT35 today,
Post by: Chuck White on December 28, 2011, 10:02:57 AM
I don't know fella's, but the one in my LT40 is either plastic or nylon.  smiley_headscratch

Which makes sense because that would be more of a lubrication affect than a steel one.  smiley_thumbsup

Pete;  Maybe the original owner switched the metal one out and the nylon one in.   :-\

I adjust mine 2 or 3 times through the course of our sawing season.
Title: Re: Found something odd on my LT35 today,
Post by: customsawyer on December 29, 2011, 04:23:03 AM
I have had 3 mills with the metal bolts and can't remember a single time that it has messed up a blade.
Title: Re: Found something odd on my LT35 today,
Post by: pineywoods on December 29, 2011, 09:52:18 AM
If there is 1/16 inch clearance and the band is rubbing the block/bolt, I'd be looking for the reason. It will be a mechanical resonance situation, and that's something thats not easy to comprehend. Slightly changing the drive belt tension or engine rpm just a tad might stop the flutter. Blade tension will also have an effect. Too much hook angle in real hard woods can also cause blade flutter.
Title: Re: Found something odd on my LT35 today,
Post by: ely on December 29, 2011, 10:03:04 AM
Tom, told me along time ago in a pm about that bolt, it started out as a bearing on a bolt. he said it was up there in case the band got to moving up and down too much it was to keep it all in check.
Tom went on to say he had seen the bearing replaced with all varieties of wood and a few plastic and other soft materials. In Toms' words "you can put anything you like up there, chances are it will never touch the bands anyway."
Title: Re: Found something odd on my LT35 today,
Post by: Jeff on December 29, 2011, 10:32:44 AM
My mill still has the bearing up there (87 lt30 )  It's seized up. Does not turn. It was that way when I got the mill. Tom also said not to worry about it, it didn't need to turn.
Title: Re: Found something odd on my LT35 today,
Post by: millwright on December 29, 2011, 06:18:17 PM
I also have an LT35 and have seen the wooden block, but it doesnt appear that it has made any contact that is visible after sawing about 15,000 bd ft.
Title: Re: Found something odd on my LT35 today,
Post by: 123maxbars on December 29, 2011, 07:58:34 PM
After alot of research and talking with my woodmizer Rep it looks like the wood block was the right side, but came loose from the two screws and was lower that it was suppose to be causing it to rub against my blade.  Thanks for the help on here!!
Title: Re: Found something odd on my LT35 today,
Post by: Chuck White on December 30, 2011, 10:21:55 AM
Glad to hear that you have the problem taken care of 123maxbars.
Title: Re: Found something odd on my LT35 today,
Post by: musikwerke on December 30, 2011, 09:32:09 PM
My 1987 LT30 has the roller bearing on the stud.  I replaced it and set the clearance when I rebuilt the mill.  It stays clean and rust free on the circumference so something touches it once in a while.
Title: Re: Found something odd on my LT35 today,
Post by: Jeff on December 31, 2011, 10:52:05 AM
It may be that its simply getting scoured with sawdust. The outer part of mine gets clean looking to when I saw, but nothing ever touches it that I know of.