Need recommend on Solenoid valve or Electic Actuator

[woodlandfarms]

So I am designing a 3pt hitch for my tractor. At the moment, it is going to be very simple, just hydraulic lift up and down. I am also trying to keep the costs down.

So my choice is either a Hydraulic cylinder with a servo actuated control (solenoid valve) or an electric actuator (cylinder).

So anyone know of an actuator that is good at being in an agricultural environment that is small that can lift 1000 lbs at least (6ft woods box blade or a 7ft land plane).

Second, my hydraulic system.... I am planning on tapping into one of my smaller hydraulic systems, I think it is like 8GPM and 3000PSI. It operates my draft control and my seat leveler.

What i want the Solenoid to do is to let me lift, float and bypass. I think normal would be bypass so the draft and seat work, and then momentary bypass to lift. But then I need to device to float. So I guess it would bypass to the seat, but how do I get the cylinder to just float?

I hope I am making sense. Sorry if I am not.

 

[mikehaugen]

well, I am not a fan of electric actuators at all. Besides you will not get any float capability unless you build it in mechanically (like some sort of slotted hole or the like). Is this something you are building for your powertrac? I am curious because I don't know why you would have draft control with already having a three point lift, unless it is for the loader. Also depending on how you design the lifting system you will need the actuator to lift a lot more than 1000 lbs if you you want the arms to lift 1000 lbs, unless you have absolutely no leverage effect by placing the pivot point of the actuator right at the end of the lifting arms somehow.

I know a little about hydraulics in general but am not real familiar with different valve configurations in the agricultural world. But I would think (and could be wrong) that if you tapped into the existing hydraulics in parallel, you could should be able to find a closed center valve with a locked position (in the center), then an "up" position with spring return to center, and then a "down" position that would allow the cylinder to free flow (therefore float) between the outlet ports. Not sure if something like that is available, but I think that is what would be ideal. Again though, I could be wrong.

 

[mikehaugen]

wow, sorry I missed that you are wanting to use an electric solenoid to control this. That may be either harder or easier to find in the configuration you are looking for. I keep wanting to utilize the rear power beyond on my tractor, but want to use electric valves. The problem is I want speed control and then you are looking at proportional valves which get real expensive.

 

[J_J]

Most solenoid valves will either be full on or off.

There is an additional valve that you can add to make a cyl float.

Add this valve after the solenoid valve and pull when you want the cyl to float.

Surplus Center - HM50 1/2" FLOAT VALVE


How to install the float valve.

http://www.surpluscenter.com/Drawing/DR9-1064.pdf

 

[J_J]

Hyd speed control can be achieved by changing engine rpm, or adding flow control like a needle valve.

or

I use something like this for my PTO hyd speed control. The pump flow that is not used just flows through the series hyd circuit.

Surplus Center - 3/8 NPT HYD FLOW CONTROL VALVE W/RELIEF RDRS137-08

http://www.surpluscenter.com/adspecs/AS9-064-38.pdf

 

[mikehaugen]

I realize that there are alternative ways to get speed control, but they become a 2 step process- select speed then move whatever you want to move. I much prefer the "push farther on the lever to go faster approach."

 

[J_J]

The valve above will do exactly that.

 

[jinman]

So my choice is either a Hydraulic cylinder with a servo actuated control (solenoid valve) or an electric actuator (cylinder).

So anyone know of an actuator that is good at being in an agricultural environment that is small that can lift 1000 lbs at least (6ft woods box blade or a 7ft land plane).

I think you could do your project easily with this real hydraulic actuator from CMC that was originally designed for boat trim. They have several actuators available with enough power for almost any job. They are self-contained hydraulics and can be made to float. The operation is electrical control over hydraulics. I have one configured as the power for a bed-lift on our Kawasaki Mule, and it has been bulletproof. They have a push force of around 5,000 lb and a retract force of around 3,700 lb. You'll have to design the mechanics of your lift, but this self-contained hydraulic system can solve your power source needs for around $500 or less. You won't have to run any hoses or do any valving. All you'll have is a wire to route and a dual-function Up/Down switch to mount.

 

[woodlandfarms]

Well, of course, best laid plans.... I got 2 hydraulic cylinders from my neighbor. Also, given the costs of these electric actuators I am now thinking of just tying into existing fel controls... Downside is getting two more hoses from the front to the back..... Argh!!!!!!! Sometimes I wish I hadn't promised my wife I could bring it in for a price.

Any idea on small electric bypass valves?

My cousin owns a yacht repair company in Seattle....I will check with him on the actuator as well....

 

[J_J]

Just about any small SCV Solenoid Control Valve could work. Just add it to any hyd circuit except the drive circuit, and in series with the flow.

You don't need to get the hyd from the front. Put the valve in the tub wherever is convenient.

If it is the first valve after the pump, it will have priority. If it is last in a series hyd circuit, it may not get any fluid if a valve upstream is activated.

If you used a divider valve, you would always have a dedicated circuit for the 3pt.