Hydraulics Hot Rail on WM Mill

WV Sawmiller · October 23, 2024, 09:37:03 AM

Okay - go ahead and tell me I have a bad connection. I know that. It may be I am still trying to activate the hydraulics on my LT 35 before I completely stop the head from traveling but in any case I have some burned spots on my copper "hot rail" on my mill. Of course most of them are right where I normally stop the head and try to use the hydraulics so I get poor or no performance of the selected function and have to push or pull the head a few inches to hit a "live" spot to get power. I've adjusted the connection point. I have never tried or thought of cleaning or sanding it or such and will check that later but it works when I move the head an inch or so to a new spot so I'm not really thinking that is the problem. I have all these little brown or green dead spots I want to remove. Any suggestions?

I have heard and tried the little Scotch brite (green kitchen scrubbies with a sponge on one side and hard green back) with limited success especially on the deeper arc burns.

I have tried fine grained sand paper which works better but is still slow. I'm scared to use a grinding stone thinking I will cut a groove in the copper and damage the bar.

I am thinking about buying and trying a can of Brasso like we used to shine all the metal we owned in the USMC but don't know how long that will take to get deep enough to really help.

I know others have this problem as I've seen it mentioned here before but has anyone come up with a hopefully fast and simple solution to this problem?

Andries · October 23, 2024, 10:06:33 AM

Seems that squirting atf on the masts is a good thing, until the power strip contact shoe says: enough!
All that sawdust, bark and crud slide straight down onto the shoe.

Andries · October 23, 2024, 10:08:31 AM

Howard, this crud will stop 12 volts in its tracks.

Andries · October 23, 2024, 10:11:41 AM

Shiny that puppy up with a 3M scrubby pad and you back in biz.

The hot strip might be "USMC level bright" and shiny, but it won't make much difference if the shoe is dirty.

Andries · October 23, 2024, 10:19:32 AM

You can see there's flash pits on my hot rail as well.
The same scrubby pad shines that copper strip up really well. The shoe is almost 2 inches long, and will span any of those flash pits without a problem.

However, if you've been having speed speed milling contests with Yellowhammer or CustomSawyer, and been rash with firing up the hydraulics before the contact shoe raced back to the hot strip, well, then your hot rail might really be in sad, sad shape.
There's two sides to that copper strip Howard. You could always just flip it over and play that music on the "B" side, right? 😁

Magicman · October 23, 2024, 01:03:50 PM

I was gonna reply until I read the above reply by Andries. He covered it very well.

I use 120 grit emery cloth to shine that strip. Also don't forget to crawl underneath and clean that ground contact.

WV Sawmiller · October 23, 2024, 08:20:17 PM

I went ahead and tried the Brasso with moderate results then sandpapered the worst spots on the rail. Next I removed and shined the bottom of the shoe with the 600 grit sandpaper. It was dark and after I shined it and retested it everything seemed to work normally. For some reason I never thought about the shoe connection. That may have to become part of my regular maintenance routine.

Thanks for the suggestions.

taylorsmissbeehaven · October 24, 2024, 08:26:37 AM

I have this going on too. I had not thought about the shoe either. Thanks to you both for the info!!

GAB · October 24, 2024, 08:48:30 AM

WV Sawmiller:
The shoe part that Andries had in his hand you need to totally disassemble and clean ALL associated parts and properly lube then reassemble.
In the future you need to quit leaving the head contacting the copper strip as the shoe spring can take a set and reduces your contact pressure. So when you are done for the day make sure and move the head far enough to avoid copper strip contact that over time weakens the shoe spring. Been there.
GAB

WV Sawmiller · October 24, 2024, 09:24:45 AM

Gerald,

I confess - I do normally leave the head in contact with the strip. About the only time I don't is when I have left it in travel mode or if I leave it overnight at a job site I like to load a log and move the head over the middle of the log and lower it till touching as a security step. (It would makes it harder for someone to steal.)

I always thought the suggestion to move the head off the rail was as a safety measure to disable the hydraulics when not in use (on my mill the hydraulics power does not go through the switch and the hydraulics work any time they are in contact with the rail) and to help prevent any possible power drain and I've never had that issue. I figure it is a chicken soup fix/suggestion. It might help and it can't hurt. I'll try to do that in the future too. Thanks.

Magicman · October 24, 2024, 09:39:17 AM

In theory maybe, but I have not seen that and have never moved the head off of the contact strip. I don't and won't. I carry a spare contact shoe kit which includes new springs and the last replacement was done in 2017 because of shoe wear, not weak springs.

When I lube the power feed chain every sawing morning, I am careful to not allow any ATF to get onto the contact strip, etc. I suspect that maybe oil contamination caused Andries shoe buildup. My shoe is always bright/shiny.

My contact strip is now 26 years old and I am not hesitant to use the 120 grit emery cloth to shine it up. You ain't gonna wear it out.

moosehunter · October 24, 2024, 11:43:16 AM

I use a 3m Roloc disc on my drill to clean the strip.
mh

GAB · October 24, 2024, 05:21:33 PM

Quote from: WV Sawmiller on October 24, 2024, 09:24:45 AMGerald,

I confess - I do normally leave the head in contact with the strip. About the only time I don't is when I have left it in travel mode or if I leave it overnight at a job site I like to load a log and move the head over the middle of the log and lower it till touching as a security step. (It would makes it harder for someone to steal.)

WV Sawmiller:
Before leaving for Alaska in 2017 I loaded a large log onto the mill the took a slab and a board off and then rotated it 180. The flat spot was to make it harder to get the log off. Then I parked the other vehicle in front of the mill inside the greenhouse as deterents to would be thieves.
GAB

GAB · October 24, 2024, 05:30:09 PM

MM:
Somewhere I read that you should not leave the head for extended periods of time where the contact shoe in in contact with the copper strip.
Now if I could only remember where that was.
Glad to read that you have been lucky, I wasn't.
GAB

Magicman · October 24, 2024, 06:01:37 PM

Except for the SuperHydraulic, etc. the downside of leaving the head on the strip was that the hydraulics are always hot. This could actually be dangerous if kids were nearby and started pulling levers. For this reason, it was recommended that the head be moved off of the contact strip.

The SuperHydraulic, etc. have a power solenoid that de-energizes the contact shoe when the key is off.

WV Sawmiller · October 24, 2024, 07:29:12 PM

Gerald,

When I do leave a log on the mill at a customer site overnight I don't worry about sawing a flat spot. I just clamp it, bring the head out over it and lower it do thieves would have to raise the head, roll it back then activate the hydraulics to release the log then roll the log off. Most would not know how or are too lazy to work that hard.

The only real down side is the extra weight on the mill for an extended period but the mill is resting on the jacks,

My manual is out in my truck but I thought it said in there not to leave the head in contact with the power strip. Seems like there may even be a warning sticker to that effect on the mill. I'll look the next time I am out there. It does look like a reasonable safety practice to keep it off the strip especially if there are kids around.

As I said and am sure you saw when you visited I normally left my head in contact but never knew of any mechanical problems it caused.

Jeff · October 24, 2024, 08:16:28 PM

I have no idea, but could the potential problem be corrosion of the connection if left in contact?

WV Sawmiller · October 24, 2024, 08:48:43 PM

Jeff,

I don't see any sign of corrosion. All I saw was burned spots typical of arching and moving the shoe off that spot allowed the hydraulics to work normally. I shined the rail at those spots and shined the shoe and everything seems to be working the best in a long time.

Shining the shoe was a new step for me but seems to be helping and an obvious (now!) area to check. Simple and can't hurt and could make a big difference in performance.

I can't see any sign leaving the shoe in contact caused any burned spots either. I think moving it off the rail when not in use is more a safety concern than a mechanical one. In all honesty it can't hurt to move it off the rail and could help.

John S · October 25, 2024, 09:18:53 AM

I made a properly sizes sanding block for the strip and use 100 grit paper. A WM tech told me if the strip is really bad, it can be flipped to expose the inner side and be back in business

Dave Shepard · October 25, 2024, 09:47:23 AM

I've had no issues leaving the head on the strip in over 16 years.
I think all hydraulic mills have had the shut off solenoid for a long time now

Jim_Rogers · October 25, 2024, 10:22:23 AM

On my mill, and it could be the case on many mills, the hydraulic levers work in two directions. Up for one function and down for the opposite function.
Thus, these levers have self-centering springs.
Now these tiny springs can wear out and brake. (you know how I know this).
As mentioned, some mills the contact strip is live, even with the key off and out, as my mill is.
So, if in the middle of the night the spring brakes (could happen), then the handle falls down activating one function. And the pump will run until there is no more juice in the battery. All the time pushing hydraulic oil into a fully extended cylinder. This could push out some seal or other damage, such as a line blowing out.

So, for many this idea of not parking with the shoe hitting the copper bar is a good idea.

Jim Rogers

WV Sawmiller · October 25, 2024, 11:00:30 AM

Thanks Jim. As I said before - it might help and it sure can't hurt. I will have to look at changing my practice of leaving it on the rail.

Ben Cut-wright · October 26, 2024, 10:20:07 AM

Electrical contact integrity of copper is diminished because of "oxidation" contamination. Cleaning solutions can remove harmful build up of oxidation, but a quicker and easier method is to carefully burnish the surface. When oxidation becomes bad enough it can create arcing at the contact surface. Copper surfaces left in firm contact with each other tend to oxidize less at the point of contact.

Copper that is evidently dull is reminder to burnish the oxidation away. The heavy build up of crud shown in Andries' image will require more than a light burnish.