Hydraulic flow controls vs needle valves. Mistake I found on my mill.

[bushhog920]

When trying to fine tune the debarker hydraulic advance and return speed I could tell something wasn't right I'd adjust one flow control and it would change the speed for the other direction. Slowed the return down then the advance would not advance. I found parker N600 needle valves on each end of the cylinder this will not work there needs to be a check valve to bypass the restrictor so adjustment can be made in both directions. I replaced them with Parker F600 ( 600 for 3/8npt ) flow control valves and now i have full control in both directions. These would also work great on a grapple the opens/closes too fast. Hope this helps someone out 

 

  

 

[Banjo picker]

I will check and see what mine has on it.  Mine does come back pretty swift, but I have never found that to be a problem.  I cant imagine running it with out that debarker.  Banjo

[redbeard]

 There needs to be some amount of give or it will really bite on irregular knots. You have too pay attention too debarker through the cut operating in out switch, if you have speed adjusted for the swing so it's fast it works pretty good.

(The hinge bushing if not we'll greased will bind up and cause slowing of the swing)

bushhog920@
Will the addition of check valve make the swing lock on the log harder with no give untill you switch the retract?

[bushhog920]

The valves are installed so the check valve is closed when fluid leaves the cylinder this is called " meter out " circuit if the valves were turned 180 check valve will stay closed when fluid goes in the cylinder that is a "meter in" circuit. Meter out is more stable than meter in and make sure both valves are in same direction. Redbeard this will make no difference than with the needle valves also cooks has a pressure regulator on the advance this controls how hard hard the blade is pressed against the log. Speed has nothing to do with pressure.

[redbeard]

The AC 36 is new too me only have 6 months of running it, I have adjusted the debarker flow controls numerous times and have found my happy place where I like it.
Curious too hear your results of modifications.

[bushhog920]

Results? Couldn't be happier like you said you can find the sweet spot and it works ok but for $160 ( $40-$70 ea online ) you can adjust it to perfection. Mine now is slowed down it will ease into the log and on return it will barely shake the arm.