1. Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!

Hydraulic cross over valve for stumpgrinder

Discussion in 'Compact Equipment Attachments' started by andrewpond, Feb 10, 2019.

  1. andrewpond

    andrewpond Active Member

    Joined:
    Sep 30, 2012
    Messages:
    43
    Location:
    canada
    Hello. I am building a stump grinder for mini ex. Aux flow is 17Gpm . Yes I know it will be slow/ not super powerful.

    The hydraulic motor i have does not free spinning (not the right term )
    I thinking of adding a cross over relief valve at the attachment.
    Found this at Princess Auto.
    https://www.princessauto.com/en/detail/30-gpm-cross-over-relief-valve/A-p8689226e
    Princess Auto is canadian version of harbor freight .
    Would this allow blade / motor to free spin to naturally slow down when not powered?
     
  2. John C.

    John C. Senior Member

    Joined:
    Jun 12, 2007
    Messages:
    5,479
    Occupation:
    Machinery & Equipment Appraiser
    Location:
    Northwest
    What you need is a motor spool in the control valve to allow spin down. A motor spool in the neutral position has open ports that allow oil to flow freely to and from the hydraulic reservoir.
     
  3. 56wrench

    56wrench Well-Known Member

    Joined:
    Dec 4, 2016
    Messages:
    106
    Location:
    alberta
    a simple solution is to use a check-valve from the pressure side to the return side on the implement just before the hyd motor -installed so the arrow (usually indicates the direction of free flow) points back to the pressure side which will allow the hyd motor to freewheel and wind down after the control valve flow is stopped. it should be the same size as the hyd hoses. I would assume the hoses are 3/4 or 1". a suitable check valve can be bought through a hydraulic shop from a knowledgeable parts person( which may or may not be found at princess auto). I think the last one I got from a hyd shop was about $60 for a 3/4 npt version
     
    rmllarue91 likes this.
  4. 56wrench

    56wrench Well-Known Member

    Joined:
    Dec 4, 2016
    Messages:
    106
    Location:
    alberta
    the cross-over relief valve should also be used to protect from shock-load- it alone will not let the motor free-wheel
     
  5. KSSS

    KSSS Senior Member

    Joined:
    Feb 27, 2005
    Messages:
    2,537
    Occupation:
    excavation
    Location:
    Idaho
    How much psi does your miniex make? Just from a GPM standpoint, I think it will be not only slow but likely not worth the effort. PSI would be an important aspect as too low and you will constantly go over relief, combined with low RPM, I don't see this being very viable. My opinion of course.
     
  6. andrewpond

    andrewpond Active Member

    Joined:
    Sep 30, 2012
    Messages:
    43
    Location:
    canada
    Perfect about simple check valve suggestions.
    Mini ex 2950 psi.....
    Thxs guys
     
  7. andrewpond

    andrewpond Active Member

    Joined:
    Sep 30, 2012
    Messages:
    43
    Location:
    canada
    HI Guys
    Stuck out of getting simple check valve. Local Hydaulic shop recommends :
    Parker DSL102N + B10-2-A8T body and CAP012D coil. It is two way normally open so you would hook that up between the two lines going to the motor. With the valve open/de-energized, the motor will free spin. Energize the valve to close it and the motor will operate via the auxiliary valve on the bobcat. See spec attached.

    This seems way too complicated and expensive.

    There are few company's in states that sell my exact set-up

    here is a youtube video with comparable mini ex to prove it should work.



    But 1 they dont have disturber in canada
    and 2 with the Canadian Peso/Value it would be over $10K !

    If I can solve this cross over value/ check system for $100 I will have less than $1k canadian in materials...