WM up/down chain repair and upgrade

[Magicman]

What do you suggest doing to not "pull the head down too tightly" onto the pin? What do you do in your daily regimen to avoid that?

Yes to what Chuck just said.  Drop it down and firm it up. 

[WELumberjack]

Thank you Chuck @Chuck White & Lynn @Magicman. When I get my replacement part from WM and get it all back together sometime this next week, I'll try that out and be more aware of how much I use the down lever to make sure the sawhead is barely resting on the "stops" and make sure that I have some slack in the lower part (and upper part) of the chains.  I wasn't aware of the stops before this week/I hadn't read that part of the manual.  Initially when I got my sawmill, my habit was to lower the sawhead to rest on the travel pin. Then during a trip to my local WM shop they said to put it down further, so the left side would go down until it stopped, and I started to do that. But I was not aware of/they did not mention the "stops" on the left side.

Here's what I think happened (which Lynn described in reply #22) - when I was putting the sawhead down, I likely kept engaging the motor after the sawhead had contacted 1) the pin on the right and 2) the stops on the left, and thereafter was pulling on the bottom chain connection while the sawhead was restricted by the stops. I did that enough times and/or the up/down motor was strong enough, and the chain-link fatigued/broke from that strain.

Is it recommended/mandatory to replace "master links" on both chains, or just the side that broke?

[Magicman]

Everything is the same age, so I would play it safe.  The cost is minimal especially when you consider if it breaks.

[WELumberjack]

I figure that since I have it all apart and the covers/guards all off, I'll fix what needs to be done. The master-links I got come in a 4-pack. I don't think I need all new chains like Jim showed above with replacing both of his chains. It looks like at the time his chain broke in the middle. Mine broke on the end link. It's a 30-year old sawmill and I assume the chains are original given the mill has ~850 hours on it.  

[Magicman]

@850 hours, I agree, but I would replace the master links, etc. since you are already there and have it apart.  Give that chain a regular soaking with ATF.  Mine gets it at the beginning of every saw day. 

[WELumberjack]

To apply my ATF I use a 2-gallon handheld pump sprayer with a wand to coat the felt runner of the carriage track that runs on the top rail, along the top rail, as well as run the wand along the chain that the power feed runs on. I may have neglected the up/down chains and the mast rails by comparison as those are harder to get to. I also find it difficult to easily lube the bottom rail. Maybe others have suggestions of what they do.

I initially tried to use a handheld spray bottle to "spray" on the ATF, but had to fill that too often and in a winter environment like WI, the viscosity of the ATF was too thick to get it to spray in droplets and the mechanism would fail easily.  In the south, viscosity probably isn't an issue. Not sure if anyone else uses other methods. 

[Magicman]

I do not lube the bottom rail because it is an electrical contact point for the hydraulics.

[WELumberjack]

Good point. I hadn't thought of that. That would be counterproductive. I haven't lubricated the bottom rail on my mill so far, because it would be a difficult thing to do from a maintenance standpoint.

So for understanding, let me ask if I got this right for the purpose of maintaining the top and bottom rails and proper lubrication. If you don't lube the bottom rail because it is an electrical contact point for the hydraulics, what should I do to maintain it? Should I treat it similar to the 6' copper strip on the left side of my mill that also helps run the hydraulics when the sawhead is back toward the hitch?

Is the top rail mainly designed for wear and due to gravity/friction and being exposed to the elements, I need to lubricate it and the felt wiper pad with ATF to keep it lubricated and to avoid rust? And I'm using ATF (compared to grease) because the sawdust doesn't stick to ATF as much as it would to grease.

Is the bottom rail used only for the electrical contact?  But roller bearings also run on that rail as the sawmill moves forward with the power feed.

What do I need to do to maintain/lubricate the track roller bearings that run along the top and bottom rails?  Do I use grease for those using a grease gun? How often?

[Magicman]

The cam followers that are on my sawmill top and bottom are sealed and I don't do anything with them until they need replacing.  I only use ATF on the chains and wiper felt that lubes/cleans the top rail.  It's purpose is to prevent sawdust buildup that will get under the cam followers.  They need to roll clean and smooth.  I have never had a buildup problem with the bottom rail.

I could see where road salt would play havoc with the bottom rail. 

[Ben Cut-wright]

I do not lube the bottom rail because it is an electrical contact point for the hydraulics.

Good point. I hadn't thought of that. That would be counterproductive. I haven't lubricated the bottom rail on my mill so far, because it would be a difficult thing to do from a maintenance standpoint.

So for understanding, let me ask if I got this right for the purpose of maintaining the top and bottom rails and proper lubrication. If you don't lube the bottom rail because it is an electrical contact point for the hydraulics, what should I do to maintain it? Should I treat it similar to the 6' copper strip on the left side of my mill that also helps run the hydraulics when the sawhead is back toward the hitch?

Is the top rail mainly designed for wear and due to gravity/friction and being exposed to the elements, I need to lubricate it and the felt wiper pad with ATF to keep it lubricated and to avoid rust? And I'm using ATF (compared to grease) because the sawdust doesn't stick to ATF as much as it would to grease.

Is the bottom rail used only for the electrical contact?  But roller bearings also run on that rail as the sawmill moves forward with the power feed.

What do I need to do to maintain/lubricate the track roller bearings that run along the top and bottom rails?  Do I use grease for those using a grease gun? How often?

The bottom "rail" should be lubricated.  It appears there is confusion between rail and electrical contact strip.

[Magicman]

I know the difference between the copper contact strip and the bottom round rail.  

The copper strip is the positive contact and the bottom rail is the negative contact.  The cam follower (s) ride the sides of the bottom rail and the spring loaded negative contactor rides on the bottom of the bottom rail.  I am assuming that the LT35 is the same as my LT40 in that regard.

[WELumberjack]

It likely is the same. I'll be at my sawmill hopefully this Thursday and take a detailed look. Lynn, my LT30HDG24 is a 1993, so a little older than your '98 LT40 super HD, but is basically a 4' shorter version of WoodMizer's LT40's of that era.  I'll also check what my manual says in the meantime and look to see if my cam followers are sealed or not or if they have a grease fitting.

Summarizing to see if I got this right:
So the bottom rail is the negative. And in order to run any of the 4 hydraulic functions, the sawhead has to be in contact with the left-sided copper strip (+) near the hitch. And in order to run the 3 electrical functions along the length of the sawmill (up/down motor, forward/reverse power feed, and in/out guide roller), the spring-loaded negative contact rides along the bottom (6 O'clock position) of the bottom rail.

Greasing the cam follower bearings (if mine have a zerk fitting) will keep those rolling smoothly (internally), but keeping the bottom rail free of rust and technically I don't want to put any lubricant on the bottom of the bottom rail in the path the spring-loaded negative contactor rides to keep good electrical contact with the bottom rail. If I wanted to, I technically could rub some type of lubricant (ATF) on the bottom rail in the path that the cam follower runs to avoid friction between the metal-metal contact of the cam followers and the bottom rail, but not in the path the negative contactor runs.  I'm not sure if both those paths are the same.  I will have to take a look.

And keeping the top rail cleaned with the felt wiper pad that's soaked with ATF will help keep my cuts smooth, prevent sawdust buildup on the top rail, and will minimize rust formation due to the top rail being exposed to moisture/the weather.

I think I got it!

[Ben Cut-wright]

I'll also check what my manual says in the meantime and look to see if my cam followers are sealed or not or if they have a grease fitting.



Greasing the cam follower bearings (if mine have a zerk fitting) will keep those rolling smoothly (internally), but keeping the bottom rail free of rust and technically I don't want to put any lubricant on the bottom of the bottom rail in the path the spring-loaded negative contactor rides to keep good electrical contact with the bottom rail. If I wanted to, I technically could rub some type of lubricant (ATF) on the bottom rail in the path that the cam follower runs to avoid friction between the metal-metal contact of the cam followers and the bottom rail, but not in the path the negative contactor runs.  I'm not sure if both those paths are the same.  I will have to take a look.

And keeping the top rail cleaned with the felt wiper pad that's soaked with ATF will help keep my cuts smooth, prevent sawdust buildup on the top rail, and will minimize rust formation due to the top rail being exposed to moisture/the weather.

I think I got it!

Section 3, page 3.5, paragraph 1: "Lubricate the lower track rail by wiping it with Dexron III ATF."

[Magicman]

And in order to run the 3 electrical functions along the length of the sawmill (up/down motor, forward/reverse power feed, and in/out guide roller), the spring-loaded negative contact rides along the bottom (6 O'clock position) of the bottom rail.

Not really.  All of the functions other than the hydraulics should be wired directly to your battery.  The bottom rail only comes into play with the hydraulics, but certainly it is always supplying supplemental grounding.  It rides the entire length of the sawmill head travel.  If the bottom rail is not making full contact you would/could be drawing some hydraulic pump current through the cam followers which would probably heat them up and .....

To address the bottom rail lube, yes I occasionally take an ATF wet rag and give it a good wipe down, but I am more interested in keeping it clean rather than lubricating.  Thankfully my sawmill has never seen salt and it does not rust. 

Ben's statement above is correct.

[NaySawyer]

To clarify, if only for me .. the old mills used a piece of threaded rod with a roll pin through the top to attach to the lower double chain bracket.  The bottom of that rod passes through the gantry's lower cross beam.

Typically when one side of the roll pin breaks, the other may pull out or fail too.  Woodmizer has an upgrade kit for this that replaces the anchoring rod/roll pin with a bolt and a flatter lower bracket.   Although there is no weight on the roll pin or rod the bolt head is allot more secure than the roll pin.  

hope this helps

[WELumberjack]

@NaySawyer,
 Yes, you are correct. When I ordered the replacement kit from Woodmizer for my '93 LT-30 last week, it came with the long bolt with a bolt head that fit snuggly inside the lower bracket such that when I installed it, I did not need to put a wrench on the top of the bolt; just tighten the nut on the bottom. (No more threaded rod with a roll pin). With the sawhead raised all the way to the top, the recommended deflection of the up/down chains pushing in the middle was 1-1.5" deflection from vertical with 5 pounds of force (using a standard belt tension gauge).  The chains are not supposed to be rigid/taut. Also, for my replacement kit, it did not come with a spring as Jim showed a picture of in reply #9, as may be on newer mills.

Either way, I got everything back together last week and am back to sawing.  Similar to what Jim described above, my experience in putting the 2 master links together with that new bracket was it was a bit tricky to fit the master link clips right next to each other. Not sure it really matters, but one slider clip was on the inside and one was on the outside of the bracket. All that matters to me is that it's clipped together and holds.  It's not like roller chain on a bike that has a single direction of force.  This is an anchor point.

To my knowledge, just replacing things as I did, did not change the accuracy of the measurement of my blade height on the sawmill bed compared to the main height gauge/ruler. Although if someone has to replace both chains, that measurement may change due to old chains being stretched and new chains being tighter.

And to solve/avoid the issue of having this happen again, when I'm done sawing for the day I just leave the sawhead suspended by the chains; I'll put it down on the travel pin, only when I'm travelling (and I'll make sure the bottom chains are not overtight!)

Lastly, I checked my mill & my upper cam followers have a zerk fitting for grease as well as the felt pad for ATF over the top rail. The cam followers on the bottom rail are sealed. The spring-loaded negative contactor rides on the 6 O'clock position under the bottom rail, and the cam followers on the bottom rail ride on the 4:30 & 7:30 position.

Being in WI, my sawmill has the potential if moved in the winter, to being exposed to salt.

[Chuck White]

The replacement is definitely an improvement over the threaded rod and roll pin that was the original on the LT40 I used to have!

I upgraded mine a couple of years before I ended up selling the mill, much easier than the earlier setup!