How do I slow down auxiliary hydraulics?

[dirt ditch]

Just got a new stump bucket grapple for my bobcat. It came with the hydraulic cylinder and I am going get the proper length hoses made for it. Thing is the bobcat hydraulic system is 15gpm at 3000psi. That little cylinder is going to open & close instantaneously with the electric over hydraulic auxiliary switch. I think what it needs is called an in line flow control valve but I'm not sure. If that is right, any ideas of how far down will the gpm have to go to smooth out the grapple's motion. any suggestions would be appreciated.

 

[J_J]

There are several kind of restrictors.

There is a washer type that has a small orifice in it to regulate the flow.

There are restrictor fittings that can be used.

https://www.google.com/search?q=hydr...iw=930&bih=545

There are adjustable flow control valves that can be adjusted to your satisfaction.

http://www.surpluscenter.com/item.asp?item=9-7960-4&catname=hydraulic

http://www.surpluscenter.com/item.asp?item=9-7960-6&catname=hydraulic

 

[cooterdude]

most newer bobcats have an electronic flow controll built in to the aux circuit it should be a small switch near where you turn your aux on and off i dont know the model # of your machine meby you could look up the manual somewhere

 

[dirt ditch]

cooter, unfortunately my bobcat is not that new. J_J, I will see if they have any restrictor fittings when I have the hoses made.

 

[joshuabardwell]

Something I have always wondered about these restrictors is, as I understand it, forcing the hydraulic fluid through the smaller orifice heats it up a lot more. Is that not an issue that has to be considered? I guess if you really cared, you could plumb something so the back-pressure went back to the tank? Or am I over-thinking things (I often do).

 

[J_J]

You are only forcing ever how much fluid you feather into the cyl through the orifice. Instead of 10 GPM of flow going into the cyl, you might only have about 2 GPM going into the cyl, slowing things down a bit.

You haven't built very much pressure until the cyl is actually doing work under load.

If the pressure builds up to the relief pressure, it will be vented to tank.

 

[Tx Jim]

Something I have always wondered about these restrictors is, as I understand it, forcing the hydraulic fluid through the smaller orifice heats it up a lot more. Is that not an issue that has to be considered? I guess if you really cared, you could plumb something so the back-pressure went back to the tank? Or am I over-thinking things (I often do).

Forcing oil through a restricter can cause oil to heat but doing so only long enough to operate a hyd cylinder on a FEL won't cause hyd oil to significantly heat.