Can I use a orbit motor and a flow control valve as a brake

[szzuf]

I am a barb wire fence contractor. I would like to build a wire unroller to put out new wire but be able to tension it at the same time. The design of the unroller will be mounted to the front of a skid steer. Up to four rolls of wire placed vertically with the wire running through and around a few rollers mounted vertically to create drag and tension on the wire. One of the rollers I would like to turn an orbit motor or hydraulic pump that would flow through a flow control valve that I could dial down to create my braking system.

I've got the idea but haven't started the trials to see if it would work. I was wondering what you guys thought of the idea?

There is one unroller on the market. Stretch-N-Go Hog | EZG Manufacturing As far as I can tell though they use a disc brake system to create tension on the wire.

 

[oldnslo]

To maintain the proper tension would require pressure control not flow control. Flow is speed and pressure is force.

Without seeing your system it would be difficult to recommend a complete circuit that would keep the wire at the proper tension at various unrolling speeds.

I believe some companies make systems like this for unrolling and tensioning hi-line wires.

 

[szzuf]

Thanks for the info. I will look around to see what they use for the power

This is a picture what a barb wire unroller looks like.
https://auctionimages.s3.amazonaws.com/35286/40216/30455013.jpg

 

[oldnslo]

Multiple spools of wire will require a seperate tensioning control for each spool.

May also have to allow a free wheel option to allow a person to pull the wire off the spool.

Straight tensioning would be a much easier circuit than continuous tension while unrolling.

 

[szzuf]

The reason for wanting a continuous tensioning system is because of rough terrain. I need to have the fence tight every time I go up a hill or down into a draw because the wires raise up in the bottoms and catch on the tops of the hills. Driving an 8' post to anchor on would drive the cost of fence higher and higher. Being able to tighten as I go and when I unroll up a hill than I'd staple it and continue driving and the same for down a hill would give me the same tension over the whole fence. Continuous tensioning would keep the wires from getting tangled together like they do when they are loosely being unrolled also. My spools are a 1/4mile long and I usually fence a 1/2mile distance at a time. Right now I unroll each 1/4mile and then tighten together in the middle with a come-a-long. Sometimes though you think the wire is the perfect tension but after going and stapling the whole fence to the posts it becomes over tight because of little ups and downs in the terrain. This brings me to my reason for looking into a continuous tension unroller.

Thanks for your input guys.

 

[rfc143]

You might be overthinking the problem. Why wouldn't a simple adjustable mechanical (spring) slip clutch on each spool shaft do the trick? You'd have to dial them in, and you might have to adjust them as the length of wire is let out (due to stretch), but they're pretty robust and would probably hold up well in a dusty/dirty/wet environment.

 

[mcfarmall]

I have worked on industrial machinery that used a hydraulic motor to turn a ballscrew in a linear indexing operation. We would lock the motor by pressurizing the case drain with system pressure. Had 5 identical machines that ran 24/5 with no problems.