mowing machine lead

[Donn Hewes]

In working on a new mower this fall I came upon a question I have asked myself before. In Lynn Miller’s mower repair book he describes adjusting the lead of the cutter bar by turning the threads on the push bar. The push bar is the heavy bar that originates under the gear box and angles up to the head of the bar. I have tried this method of adjusting the lead a few times on different machines and never found it to make much difference.

From a purely theoretical point of view, I think those threads were there to match the threads in the timing bar (the bar in front of the knife) and assist in adjusting the timing. Before the bolt with the concentric ring was added I don’t think there really was a way to adjust the lead. In talking to Leon Brubaker of Brubaker machine in Pa, he agreed with me and said that the loss of lead comes from the push bar loosing their proper angles (bent). They have been using a heavy shop press and a custom jig to rebend push bars back to their original design. I am going to get one of these bars in a couple weeks and will try it to see how it does. I asked him how well he thought the rebent bar would hold their new shape, but he didn’t say much. He said he thought they were doing OK.

[Mark Cowdrey]

Donn,

When I rebuilt my #9 I successfully adjusted the lead by adjusting the push bar (“coupling bar”) where it screws into the yoke (“inner shoe hinge”) and the timing bar (“coupling bar brace”). We also did the same at the mower workshop at Fairwinds Farm last May.

As the push bar is attached at the back of the inner shoe yoke and the timing bar at the front, lengthening (by screwing) the push bar or shortening the timing bar increases the lead of the knife. The trick is to get the lead where you want it & then get good timing. As the push bar is more difficult to adjust, I do that first. If I recall correctly, one turn of the push bar gives approximately 3/4 – 1″ of lead adjustment on a 5′ bar. Chances are that after the push bar is adjusted, the register (timing) will be off. I then adjust the length of the timing bar to re-time the cutter bar. Note that the recommended lead is given as a range, as you rob Peter to pay Paul getting both lead & timing to be acceptable. I typically have to adjust the push ar twice to be satisfied. Acceptable timing for me is if no part of the blunt end of a new knife section is exposed at the side of a guard when the knife is “centered” in the bar.

Any & all of this is best done with nice snug pins in the yoke so the cutter bar is not sloppy.

I expect those rebent push bars will stay straight about as long as they originally did.

Donn, you probably already know all this. Maybe hearing it in a different way will be useful… Looking forward to seeing you at APFD.

Mark

[ngcmcn]

Donn and Mark, funny you guys should bring all this up cause i’ve been going through all this myself. Lynn Millers book is a bit deceptive about the threading out to adjust the lead with the push bar. It only works to some extent. In my case it torqued the pitman plate at the fly wheel end to the point that it broke as well as causing more vibration then i wanted but the lead and register was perfect and mowed well through August 1st cut I got a pattern of a straightened push bar from Leon and mine was out to France. The pitman and knife need to be in a pretty straight line to work right. Maybe the ends of that push bar could get cut off and re welded to a braket of some sort that would allow better adjustment, and had adjustment built in It looks like mlld steel to me, bent after being milled.

Good luck, glad to hear some one else is messing with this same issue. I plan to get some bars bent for future mowers. The other thought i had was about I&J’s GD forecart? Why couldn’t they adapt a new sickle bar onto that?

Just a thought. Some one one of these days is going to come up with a newer GD mower of some sort.

N.

[J-L]

According to Sam Moore (I think ?) the GD cart’s were hooked to both sickle mowers and a 9′ haybine and displayed this year at HPD. I never heard how they worked but apparently good enough to show. That shows some promise for ground driven, new manufacture mowers after a fashion.
My #9 mower has adequate lead so I haven’t messed with it. I did have to adjust my #4 JD. It adjusted just fine by moving the washers from one end to the other on the same bar. It did have to be re-timed however as it was bad out of register.
I can see where this won’t work forever and am glad there is a solution with the new pushbar.
Not everything Mr. Miller says is gospel, but usually it’s the best place to start that I know of.

[Mark Cowdrey]

I saw the GD forecart with the 9′ haybine. I did not see it with a sickle bar. The GD forecart that they were showcasing is a new, heavier model than what was at APFD last year. If I remember correctly, they had a four-up on it and they walked right off with it & started laying down grass from the get go. It was quite impressive. They were talking about marketing it around $3500, again, if I remember correctly.

Mark

[Donn Hewes]

I think adjusting the push bar threads to achieve proper lead is a method that may be limited to mowers that only lack a small amount of lead. I think one thing you will note as you try to get the lead and timing this way is that when you are done you will be pulling on the timing bar to get it back on the mower at the flywheel. I have also found on mowers that needed more than a little lead that I was torgueing the pitman so it wasn’t square to the drive shaft.

After I talked with Leon Brubaker about bending a push bar I went and compared two old push bars I have from mowers I have taken a part and a third from the one I was currently putting together. None of them matched. the one with the best angles got me the best lead, but even after I tried to adjust it a few times I was still lacking about an inch. I think I had gotten all I could and the mower works OK. That is the bar I will compare with their rebent in a couple weeks and see if that can make for a perfect lead.

These are just some things I am thinking about. I have found the mower book to be very useful, and wouldn’t want to take a mower apart with out it. Just something to think about.

[ngcmcn]

Donn, one Amish man nearby here in Maine that i’ve talked with about mowers seemed to think that about 23 inces or so was the measurement for the distance from a straight edge layed tightly to the thick end of the push bar(threaded) and extending out so you could measure up to the small end of the push bar that goes through the frame. The push bar is the hypotenuse, the straight edge is an adjacent side, and your measuring tape the opposite side of the triangle so to speak. I checked several push bars using this method and got any where from 26′ to 21′ for the bars I had. The pattern Leon sent me was somewheres around 20″. I’d have to double check on that to be exact, but thats close.

I was looking at a push bar today thinking , why couldn’t you cut one close to the threaded end bend and, hinge it somehow and put a bolt to adjust it. Not rocket science.

Not much more hay for us this fall we’re going to graze our critters as far into the fall as the weather will permit.

Donn,this summer i picked up a small Vermeer round baler (3×4).. We did everything but bale with the horses on some distant groundd. Ever consider pulling a round baler with your forecart.?

neal maine

[Donn Hewes]

i have never pulled a round baler but am pretty sure it would work fine. We wanted to do it last year at NEAPFD but were short a piece to hitch it to the cart.

At home we prefer small square bales for a variety of reasons. I have all ways maintained that a good round bale was as good as a good square bale; but the average wasn’t as good. Most of our hay goes to pregnant sheep so quality is very important to us. We also like feeding in the winter with out starting any equip. We used to have two tractors, one for the snow plow and one for the spike in the winter, but now only one.

Your spare push bars were exactly like what I found. Some of those will never work with out being bent. The only draw back to trying to hing it is the tremendous force built up right there. That is why the bar is so thick.

As for the ground drive carts, I think it will be hard to make something more efficient than the best of the old style mowers. I would love to see some one make a new one. Some one once said there was a place in Poland were they made them. Don’t know if that is true – would love to see it if it was.

[Plowboy]

Rudy our local Amish equipment repair guru also uses a press to achieve proper lead on the mowers. Gotta go harness 6 horses to cut corn for the silo fill this weekend. Trying out our freshly rebuilt mcCormick binder this morning. They say good weather this weekend so we need to cut a bunch ahead today. We’ll have 3 binders going this morning hopefully. Also have to mow some clover and load greenfeed with the hayloader today so we don’t have to this weekend. Tired horses this evening I’m thinking!

[ngcmcn]

Donn, I’ve always done square as well but this round baler makes 3×4 bales that weigh about 500-600 pounds or smaller. I was amazed at the quarter mile of windrow it would suck up. The Amish up north in maine are putting 30hp motors on them to run hydraulics and pto. One guy said his mules when pulling a Round baler knew from the weight when it was full and would stop then back up to unload.

N

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