wmz claw turner

[drobertson]

I thought about posting this some time ago, and just figured it really did'nt matter that much, but while at the mill yesterday doing a lil maintenance, I thought I might as well ask you folks that have the claw turners.  Does anyone have theirs(claw) pull up or (in) overnight, and the back stops drift down just a bit as well. As I said not a big deal, just wondering,   david

[terrifictimbersllc]

Never such a thing.  Instead they seem to drift up a bit in line with the blade must happen while I'm making the cut. 

[Bandmill Bandit]

 A) you have a leaking ram rod seal inside the cylinder OR the bolt that holds the plunger to the end of the ram is loose. 

OR

B) Leaking seals in that valve. IF it was the valve it would likely be more noticeable while you are operating the mill.

Based on the way that system is plumbed and set up I would say your side support ram is the first place to look.

They are not difficult to repair but can be a PIA to get open. Be careful not to squeeze the cylinder in the vise and get it out of round.   

[drobertson]

I will give it a closer look, not loosing fluid, and no signs of it around anything,  everything is holding good while running, its just when I shut down after a lil while it starts to ride up, thanks for the input, I will give it another go over,   david

[Chuck White]

David, when the claw drops down, do you have a log resting against it?

If so, perhaps that added pressure against the hydraulic system is to much for the system to hold over and extended period of time.

[drobertson]

I will get a pic of the position of the claw in just a few min.  Heading to the mill to get that pic,  and no, it is an empty bed, no pressure should be in the system, I think,

[drobertson]

Here is the position of the back stops and claw after resting over night,

  

 

[WH_Conley]

I have had the claw come up like that over night, never had the backstops move. Happens mostly in the summer time. I just figured it was to the fluid changing temperature. Never really gave it any thought.

[Magicman]

Yes, mine does drift up overnight, but not a significant amount to cause a problem while sawing. 

The up/down cylinder on my two plane clamp started drifting up while I was sawing which did cause a problem.  The rebuild kit from WM was about $20 and the instructions were detailed.  It only took an hour or so and I was back into business.

[drobertson]

Well howdy Lynn,  I was kinda waiting on your post,  this has not been an issue at all, just one that has been on going for awhile,  I got board, and thought I would ask,  thanks,   david

[Bandmill Bandit]

I would say internal plunger seal on the side support ram. You won't see any external leakage at all.

At least that is where I would be looking first then the claw ram.

[Brucer]

Hydraulic fluid contracts as it gets cooler and expands as it gets warmer. Since the rod end of a cylinder has less surface area than the other end, the cylinder will move to equalize the pressure. It's not uncommon to see a small amount of movement if there's a large temperature change between shutting down the mill and getting ready to fire it up again.

On the other hand, if there is any internal leakage the expanding (or contracting) fluid will move to the other side of the piston to reflect the change in fluid volume. A fully retracted cylinder holds less total fluid than a fully extended cylinder. This can give you a large amount of movement if there's a big temperature change.

I'd say from the pictures that you've got some internal leakage.

Also remember that the turner and side stops are connected sequencer valves to there may be some interaction between the two systems.

[drobertson]

wow, I knew it had some things going on internally, but never had issues with it while running, I reckon this spring when it warms up I might get industrius enough to look into it,  thanks guys for the input,  ;D

[Bandmill Bandit]

Very good description Brucer. I didn't have time for to include the detail you put into it.