Problem with sickle bar lift speed

[stowester]

I've added a bracket and piston to my IH sickle bar mower and use my rear remote to operate it. It works much better then the original lever under the 3pt arm to lift the bar. The first 2 pictures show this modification.

The problem is that it lifts too fast and can flop the bar higher than the pitman arm can handle. I've tried to slow it down with a home made (nearest TSC is an 3/4 hour drive each way) 1/16 orfice (last 2 pics). I made the orfice in a 3/8 to 1/2 bushing and use it between the hose and the QC at the tractor on the lift side.

With this orfice in place the mower will raise at the speed I want but will not go down at all. The hyds just squeal as the pressure relief does it's job. If I shut the tractor off and operate the valve the bar will go down fine under it's own weight.

I've since opened the orfice to 3/32 and counter sunk the holes, same problem.

Any ideas as to what's going on?

Dean

 

[Farmerford]

Just a guess.

If the orifice is on the mower side of the QD, when you lower the blade rapidly a stream of high pressure fluid is hitting the back side of the poppet or ball valve in the QD. If the QD is worn, or if you are using different style QD nipples and sockets, it is possible that there is enough slack in the valve that the fluid stream is closing the valve and blocking the flow.

When you lower without the power on, you don't get the same high pressure stream because the pump is not moving the cylinder; only the weight of the blade.

If I am correct, move the orifice to the cylinder/hose connection and it will work.

 

[stowester]

Farmerford; Good idea, that seems like the senario. I'll try an elbow first to see if that helps. If it does, I'll build another orfice to fit onto the piston end.


Thanks,
Dean

 

[Farmerford]

Dean:

Consider also that there could be trash in the cylinder/line, such as piece of an o-ring or piston seal, that is too small to stop up the QD but too large to pass through it. In the past it just travels up to the back side of the QD when the fluid moves rapidly and then stops. But if the orifice is in the path, it may be big enough to plug the orifice (it is amazing how something relatively soft can withstand a lot of pressure if it is confined). When you reverse the flow it passes back down the hose into the cylinder. When you lower the blade slowly it may not get pushed up the hose because the fluid is moving so slow.

Sometimes these things sink and sometimes they float, so that can affect how they behave.

Once I had a flap of inner hose lining peel back where the end fitting went into the hose. It would block the flow when the fluid traveled one way, and flow freely when the fluid went the other way.

 

[kennyd]

If FarmerFords idea does not work, Then perhaps THIS will, it will allow flow control in one direction, but free flow in the other.

 

[stowester]

Problem solved!

FarmerFord was right on the money with his first post. The fluid coming out of the orfice was shutting off the QC. I added an elbow to the fitting and finished mowing the pasture.

Then I welded a piece of 20 penny nail, laying across the countersunk area, to break up the stream. This way I could have the esthetics I want in the plumbing.

All I need to do now is rebush the brakeaway pivot on this mower and it'll be better then new!

Thanks for the all the help!

Dean

 

[stowester]

If FarmerFords idea does not work, Then perhaps THIS will, it will allow flow control in one direction, but free flow in the other.

Kennyd; I thought of that but want to slow the travel in both directions. Of course $$ and time also came into play.

 

[Farmerford]

Dean:

Since I guessed the problem, I am entitled to one comment.

I am not sure why you think that "esthetics" has any connection to home-made orifices, welded 20d nails, and an ancient IHC pittman drive sickle mower, and even if it does I doubt if the addition of an elbow in the hydraulic line will damage it much.

Actually I am jealous because I mowed pasture in 1950's with a JD "B" and sickle mower that was as old as back then as yours is now. And I am seriously considering a new sickle mower to replace my 10 year old Bush Hog rotary just for the quietness. But they don't make IH any more and NH wants $5,000 for a new pittmanless style.

How many acres are you getting from your sections and guards?

 

[stowester]

I also spent a summer mowing with a JD B and sickle mower. It had armstrong steering and a hand clutch. I did have Hyd lift but the clutch had to be engaged in order for it to work.

Most of the time we mowed pastures with a IH 460 and a IH pitmanless mower.

This was all working on my uncles farm as a kid.

For the last 20 years I had my own Farmal Cub with L22 mower and only did the pasture in front of my house as it's too rocky (actually only 1 rock that sticks up in alot of places) for his modern mowers. About 7 acres.

I mowed it once this year with my RM but didn't like the way it looked. I found this IH mower locally and have enjoyed fixing it up. I would prefer a pitmanless and will keep looking. I've remowed the 7 acres plus another 8 that he normally mows. I like the look of the sickle mowed field much better.

So now that I made you read all that, I'll start on your question (but not really answer it)

My sections and guards are short lived because of the ledges and rocks. I only sharpen once and usually replace 1-3 each per year.

I bought a complete set of sections and a bunch of parts from sickleservice.com. A great guy to work with.

Dean

 

[Sheepdr]

Could you please send me some more pics on how you built the ram set up? I would like to put one on my # 24 int mower. I wonder if a one way ram would work since you don't need down pressure. I know this is a little late but haying time is a little busy as I'm sure you know. I'm having trouble with mine plugging up at the outer end. I just found out that I should have a section and a half on the end. Have you had any trouble like that? Please let me know any problems you have had with yours. People like us need to help each other. I know I need all the help I can get.
Hope you had a good season, about done out here.