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Woodmizer lift chain....

Started by mrcaptainbob, May 27, 2010, 11:21:46 PM

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mrcaptainbob

Woodmizer has a neat manual way of lifting the power head using the Z shaped chain lift. The question we have is why IS it in that 'Z' fashion, and why are the two center spurs connected with their own chain? I can see there's always a good tension on the chain up and the chain down. Is there a tensioner in there that takes out any chain slop?

Jeff

I just got done adjusting mine on my antiquated lt30. I can tell you my observations on it, but I don't know if they are the same as newer models.

There is a tensioner on the bottom that takes that the slack out. The adjustment setting is to be 1.5 inches of deflection at midpoint in the chain.  The z chain configuration allows the head to "Climb" up and down. To  adjust it, you move the head all the way to the top, then chain it up, then adjust your chains to spec, then unchain the head. You could also block it up from the bottom. You just have to remove the weight of the sawhead from the chains to do the adjusting.

The bottom of the twin chain is where the tensioner is, plus the chains are connected to it with what I would call an equalizer. An anchorment that both chains connect to that is sort of a rocker device that equalizes the tension.  There is also an adjustment on the top end on one chain to allow a small adjust for the difference in length of the chains.

I ended up taking two links out of my chain to restore adequate travel on the bottom tensioner.  Its working really good again for a 24 year old mill.
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

Jeff

After several days of resurrecting my mill that someone else modified without my knowledge over the winter, I'm going sawing in the morning for Gene, my Mother-in-laws husband.  I have no idea what all he has, I just hope hope its not the tree in the front yard by the driveway. :)
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

Jeff

Well, I'm bummed and discouraged right now. The day started out good, but about 12 logs into it, something let go in the up and down system I had tried to put back together.  I dont know what's wrong yet, other then all of the sudden, the head would only creep up. I started looking and noticed that one of the twin chains in the lifting system was slack and the other had went fiddle tight.  The drive motor was hot enough you could not leave your hand on it. All I can think of is one of the bushings or bearings, or whatever is in the sprockets went. I dont know what else could make one chain tight and the other slack like that, that quick.
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

Warbird

Ugh.  I'm sorry to hear that.  :( 

Tom

The idler sprocket's bearings giving up would be one thing I can think of.  To make one tight and the other loose, the head would have to be tilted.  I don't know what to look for that might be broken, but checking the post/head alignment would be one thing.

Hot motor could be a too-tight belt too.  That's probably not the case since it  has nothing to do with the belt. 

Let the head all the way down and see if you can get some of the tension off of the chain that is tight.  That might give some indication of what is loose.

Did your chain adjuster break?

I lean toward an idler sprocket with a bad bearing.   In a pinch, one time, I had a machinist cut a press-fit for a new bearing into the old sprocket.

Those idler sprockets aren't expensive.

Jeff

When it cools down a bit out side, I'll go out and look closer. I already tore a chunk out of my pinkey finger today while fooling with it and not thinking.
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

Jeff

I'm baffled.   I got the head all the way to the top with a struggle.  Manual lifting under it with my shoulder and running the motor at the same time. When I started this morning, both chains were equal. in tension, and both had around 1.5" of deflection.  At the time I quite sawing, and up until I tore it all apart a few minutes ago, one chain tight, with zero deflection, and the other one very loose.     

I chained the motor off, then run it down a little, I had a hard time finding a center point where the tight chain was loose enough to take apart.  I took both chains off.

Observations are that everything seems normal.  The idlers all spin free.  I but a big screw driver under all of them and tried to pry around, looking for movement, and the bearings ans shafts all seem fine.  I checked the gearbox.  I pried on the shaft, and don't seem to have any side movement in the shaft.  The roller chains seem to be fine.   I just cant see how in the world the one chain could possibly tighten up like that.

There was nothing in the sprockets. No debris.
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

Jeff

Additional info:  the motor and gearbox run smooth with out the chains on it.  The head lowered easily, so there doesn't seem to be any bind in anything, but it was all the motor could do to lift it, in fact it really couldn't. That's why it got hot, I am sure.
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

Tom

When it starts binding again, see if the sprockets might be worn and the chain climbing out toward the ends of the teeth.  That would make the sprocket be effectively bigger and tighten the chain.

Jeff

I took the chains and the adjuster completely off.  I'm wondering now if my wood-mizer was previously modified from a one chain model?  I got my owners papers out that came with the mill, and the diagram shows a one chain, one sprocket setup.  Did the older models have one chain?  





I don't think this looks factory. This is how the chains are anchored to the tensioner that goes through the frame. My paper work and parts diagram does not show this. The only thing keeping that chain connected to the tensioning bolt, is that pin you see there.





These idlers all looks okay to me, but I have nothing  to compare it do. I do think they are okay, as if they were not, it seems that prying on them would show it.





I did get to saw a few logs before things went haywire.  I had to set up in tight quarters.





Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

Tom

That chain configuration looks like my 1990 model.

Just a stupid guess, but is the chain well lubed?


Warbird

That's a weird one.  I'll ask an obvious question: are both chains still the same length?  smiley_headscratch

Jeff

It is lubricated. No stiff links. I did just lay the two chains together on the driveway, and one is once full link longer then the other.  I'm going to cut that link off, and start from scratch putting it back together.

Does the way it connects to that adjusting bolt look normal then?
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

isawlogs

Same as my '93 , make sure you have same amount of chain on both sides , of the sprockets , you may inadvertently had one with one longer link . If none of this happened , get a new chain rollers may be seized and also , take Murphy for a walk to the lake and drown um .  ;)
A man does not always grow wise as he grows old , but he always grows old as he grows wise .

   Marcel

isawlogs


   Yes Jeff , that part of the assembly is ok . it just looks that way  ;)
A man does not always grow wise as he grows old , but he always grows old as he grows wise .

   Marcel

boman1

Quote from: Jeff on May 29, 2010, 06:07:10 PM
Additional info:  the motor and gearbox run smooth with out the chains on it.  The head lowered easily, so there doesn't seem to be any bind in anything, but it was all the motor could do to lift it, in fact it really couldn't. That's why it got hot, I am sure.

Jeff...about six months ago I had a similar issue with my LT40SH.It ended up being a bad bearing in the gearbox.When I took the load off it the gearbox appeared to be fine....but when the weight of the sawhead was on it the gearbox would bind! Good luck with it.

Gary_C

One other thing to check is the place where the pads slide on the mast. If the mill has been sitting outside and those unpainted areas are rusty, they could cause the head to bind as it goes up and down. If they are rusty, sandpaper the rust off and lube those areas.

I had that problem on my mill as it sits too much and it was tripping the breaker on the up-down motor.
Never take life seriously. Nobody gets out alive anyway.

trapper

my 83 lt30 has the double chain
stihl ms241cm ms261cm  echo 310 400 suzuki  log arch made by stepson several logrite tools woodmizer LT30

Kevin

Taking two links out of the chain may have caused a problem.
Can you restore the chain to manufactured specs?
Might be time for a new chain, how do the teeth on the sprockets look?

Jeff

Last night I took the chains out and laid them side by side and made them identical length. I've had some experience with roller chain over the years, and these seem to be okay. They are still tight side to side with very little side bend in the length of the chain.

I put it all back together and tried it.  First thing I saw was one of the chains start climbing on the small drive sprocket on the gearbox. It took two seconds for it to jump, making one chain tight and the other loose again.

I'm thinking that the lubricant in the chain is inadequate, so I took it off and completely saturated it with rust reaper. The little drive sprocket does not look overly worn, but it may be.

The side slides are not corroded, but again, it may be I need a different lubricant. I checked this morning and it feels sort of gummy.  I've been using a cheap spray lubricant on it and I think I need something better.
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

Kevin

I had that trouble with my LT-15, really jerky bringing the head down.
I replaced the short outside chain with a new one, tensioned the long chain and it's working good again.

LOGDOG

Jeff,

  Are you able to take a short video with your digital cam and post it showing the hop of the drive sprocket on the chains? Just out of curiousity, take a look at the distance between each of the 4 slide pads on the mast. I'm looking for the distance in between the pad and the mast face where the pads travel. Normally I think we check the measurement with the head all the way up and all the way down. Just curious if maybe the alignment is out causing a bind on the head travel up and down. Seems like I dealt with this once on my first mill way back.

Jeff

There is no visible distance between the pads and the mast head.  While it was cutting yesterday, it was cutting perfect lumber.  I just found another problem I had not notices, and I think all of these had a cumulative effect. Hardly any juice left in the battery and the amp meter was reading zero.  Turns out I had a loose connection coming from the charging system back to the battery. A spade type connector in a plastic clip. The spade had backed out of the connector. I tightened it up, and am charging again.  There was plenty of juice to start the engine yet, but it certainly was having an effect on up-down.
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

Gary_C

From what you are describing, it sounds like those chains are stretched and need replacing. Take the chains and lay them down on a flat surface and push the ends together and then apart. If there is a lot of movement or slack in the chains, they need replacing. That slack is what will cause the chain to not lay flat over the sprockets. In essence, the pitch has changed too much.
Never take life seriously. Nobody gets out alive anyway.

Jeff

After adjusting the chain lengths to be identical and completely saturating with rust reaper, then reinstalling and readjusting, I'm not getting any of the chain climb I got before.  Somehow I've always had the idea the side mast slides and pads should be lubricated with transmission oil.  I just wiped a thin layer of grease instead on them with my fingers and that seemed to make a world of difference.  A hot battery makes a difference to.  Everything seems to be working good now. It does not go up near as fast as it comes down, but it may be going up better then it ever has.  I guess I'll know more when I get it back out and start sawing with it.
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

Kevin

They want you to use transmission fluid because the grease will pick up and hold sawdust.
I use the fluid on the chains and slides.

Jeff

Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

trapper

may be a dumb question but are you calling atf transmission fluid?  My old manual says WD40 on the chains but they now recomend atf.
stihl ms241cm ms261cm  echo 310 400 suzuki  log arch made by stepson several logrite tools woodmizer LT30

Kevin


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