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Hydraulic cross over valve for stumpgrinder

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

  1. andrewpond

    andrewpond Well-Known Member

    Joined:
    Sep 30, 2012
    Messages:
    53
    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

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    Location:
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    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 Senior Member

    Joined:
    Dec 4, 2016
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    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 Senior Member

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    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

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    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 Well-Known Member

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

    andrewpond Well-Known Member

    Joined:
    Sep 30, 2012
    Messages:
    53
    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...
     
  8. greg9504

    greg9504 Well-Known Member

    Joined:
    Aug 29, 2005
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    138
    Location:
    Ottawa Ontario Canada
    Is the problem you can't find a supplier? Princes Auto sells 1/2" check valves online.
    Motion Industries has 3/4" online:
    https://www.motioncanada.ca/productDetail.jsp?sku=00276055
    Or ebay...
    https://www.ebay.ca/itm/Hydraulic-check-valve-3-4-NPT-Pump-Oil-3000psi-no-return-valve-single-way-US/262144149963?_trkparms=aid=222007&algo=SIM.MBE&ao=2&asc=20180124145912&meid=7a8e9ce711f0482cbf9bf786af87c02e&pid=100005&rk=4&rkt=12&sd=262211593958&itm=262144149963&_trksid=p2047675.c100005.m1851

    As for DSL102N + B10-2-A8T body and CAP012D coil combo, the total cost is $110US plus shipping from the first google hit that came up (partsgopher). Doesn't seem that expensive or complicated. The only thing is that the valve they quoted you (DSL102N) only has a flow rate of 8 GPM. https://tejas.hyd.com/uploads/5/2/5/7/52570035/svsection_2w2p_dsl102.pdf
     
    Last edited: Feb 19, 2019
  9. andrewpond

    andrewpond Well-Known Member

    Joined:
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    Location:
    canada
    Thxs Greg.
    I am owner/operator, have not rapped my head around hydraulic yet...

    I thought I looked at Prin Auto, show link to my fabricator and he said that would not work.

    Local Hydraulic supplier who sold me the motor recommended the DSL102N + B10-2-A8T body and CAP012D coil combo verbally said $300 to $400.
    So nice if the local supplier to spec 8 gpm when we need 17 gpm :(
    That is seem expensive, I did not find the ebay valve when I searched.
    The complicated part would be adding a 12 v controled circuit. Just one more thing to add to machine and latter brake or be damaged.

    Will the ebay check valve allow the motor to free spin down?
     
  10. greg9504

    greg9504 Well-Known Member

    Joined:
    Aug 29, 2005
    Messages:
    138
    Location:
    Ottawa Ontario Canada
    Have you looked at https://baumalight.com/stumpblaster/en/ex-s18.php ? They are made in Ontario. You should look over their motor options as they show displacement suggestions for various flow rates. They also have a chart that shows flow rates for various machines under load, which may not be what you think your machine actually has. Also you can see they use a relief valve on their grinders.