Why Mowers Clog and Possible Solutions?

[Does’ Leap]

Seems like many of us have had a tough time mowing this summer. We knocked down 8 acres of some nice second cut over the last two days and had a tough time with it. It wasn’t the worst mowing I have ever done, but far from the best. I am hoping to generate a discussion on why mowers clog and possible solutions.

The biggest problem I had mowing this meadow is clogging on the outer shoe. What seemed to be happening is that it was tearing up what I call rotten grass before it was cut, bunching on the shoe, and pushing over the remaining grass before it could be cut. This “rotten grass” – brown and moist – seems to be a function of high soil moisture and lack of light penetration. Also, the temperature (60s) and weather (cloudy) doesn’t allow drying at this level down into the sward which might alleviate the problem.

This phenomenon of catching uncut grass happened all over the cutter bar, but particularly on the outer shoe. My theory is that this was due to the outer shoe being proud (out ahead) of the other guards by at least an inch. Anyone know why? I think that the shorter guards in the middle of the bar enabled that snagged grass to make its way back to the knife and therefore be cut before clogging.

Depending on the input here in the forum, I have thought of two possible solutions. The first would be to grind back the guard on the outer shoe to the level of the cutter bar shoes. On a related note, I have seen that the new “Easy Cut” system advertises “blunted” guards that are less likely “to pick up trash”. I haven’t looked to closely as the next option, but here it is: Cut off enough of the outer shoe to maintain enough integrity to support the grass board and cutter bar leveler and replace the outermost guard with a stub guard.

Any thoughts on my theory/solution in particular and other reasons for clogging and solutions more generally?

Thanks.

George

[mitchmaine]

hi George,
before you start grinding, there is a special section that you can get anywhere, that looks like two mini sections made in one made to go on the end of the knife that helps somewhat. but, bottom line, its late summer and mowing can get frustrating.
push come to shove, I will be interested in hearing how your grinding works.
mitch

[Does’ Leap]

Hi Mitch:

I already have that section on my mower. Do you know what that double knife section does to increase performance?

George

[mitchmaine]

hi George,

nuts. have you tried tipping your bar down in front closer to the ground?

I think that double section has two edges closing in under the guard with a smaller bunch of grass in each making it a finer cut. in easier grass it keeps that ball of grass plugging up the hole where the knife passes through. most of the time my troble is down at the heel of the cutter bar. I have three pea guards there now and that helps a lot.
but I know what you mean about the rank bunch off wet grass down by the cut. the old guys used to talk about wire grass as the summer passed making it hard to mow, but never identified it.
are your sections smooth or serated? I’ve always used smooth thinking serated sections needed pto when you got into hard mowing, but have no way of proving that.

mitch

[Jay]

The thing I find most problematic is when “rotten grass” catches on the point of any of the guards and then more grass catches on that and bingo- a plug. My suggestion to George is to sharpen the point on the outer shoe to try to prevent the grass getting any place to catch there.
I have used one of those special end of the knife sections and didn’t find it to be much better than a good sharp blade and ledger plate in the outer shoe that matched. That is the thing I’ve found to be most critical over all – ledgers all lined up level and the knife flat on them, held down lightly.
Recently I have been running serrated knife sections as that’s what I’ve found easiest to get. They don’t seem to take any more effort to pull and they cut well.
Jay

[Does’ Leap]

Mitch, I run 3 stub guards (same as pea guards I assume?) as well and had virtually no clogging at the inner-shoe. I have heard some Amish guys who run stub guards along the whole cutter bar. While I have much less clogging with the stub guards, they tend not to cut as well occasionally leaving thin wisps of grass behind when the mower never clogged. However, this seems like a good trade-off in these conditions.

I run serrated knives which have worked well for me. There were thick sections of this hay field where I would be plugging every 20′. I ended up asking the horses to trot through these sections and this helped a lot. When I was mowing I also started hitting the foot lever to preemptively eject the grass that was bunching on the cutter bar. As soon as it dried a bit (still damp – but not wet – at 3 pm!), things started to go better. I don’t think the “rotten grass” – least on my hay fields – is a different species. Just stuff that hasn’t seen the light of day for a long while.

Jay, I agree that you can’t start talking mower refinements without having a well tuned mower (lead, timing, knives, ledgers, etc.). I used this same mower to mow a huge first crop on this same field in July and it only plugged a handful of times on the entire 8 acres. I like your idea of sharpening that outer shoe. I also plan on polishing it up a bit as the pitting in it might add some resistance therefore increasing tearing/bunching. Any reason why this outer shoe is ahead of the rest of the guards? Thoughts about grinding it back so it is even with the others?

George

[Donn Hewes]

Hi all, Glad to see someone other than me starting the mower thread for a change. George, do you have good ledger plates in the outer shoe itself? Sometimes these are overlooked as all the rest are repaired or changed. Someone else recently mentioned pointing, or polishing and painting the the outer shoe. Instead of tipping the points down to get under stuff, you could also try leveling them or tipping them up to get the shoe point of the ground. Do you change the height of the bar (adjusting the bolts – inner and outer shoe) from first cutting to second?

I have never had a great plugging problem on that point, but often had trouble because the grass board is holding too much before it lets go of big clumps. This seems to be a common problem in the really heavy cutting. Someone recently mentioned a “rolling” grass board in Lynn Miller’s book. As soon as I get a chance I will look that up.

Second cutting cutting should just be a matter of making sure everything is sharp and running good. Green grass is always harder to cut than the tall stem.

[near horse]

Sometimes heavy wet grass will lodge (lay over) so sometimes your knife is cutting into the tops of grass that’s not growing directly in front of your cutter bar. That is a recipe for plugging even with a swather. When we fought that years back we tried to get “under” the lodged grass by angling our bar down …… mixed results. Just damn tough cutting like that.

Wire grass in our area is also known as ventenata but others also call some bluegrass “wire grass” as well. Not much leaf and a pretty thin stem (smaller than a pencil lead) but not so easy to cut.

Donn – I’ve seen the drawing of the rolling grass board. It looked to me like a simple wheel with height adjustment bolted on to the outer shoe assembly.

I think the outer shoe point acts to separate the grass or crop to be cut from that left behind. You usually have something similar on combines and swathers.

[Does’ Leap]

Hi Donn:

I have only rebuilt 3 mowers and I installed new inner and outer ledgers on all three. They were pretty inexpensive, but critical. I generally do not have many problems on the outer shoe, but not this time. I tried tipping the knife every which way and settled with it level with cutter bar on the ground. I did not try raising the level of the bar. Perhaps that would have helped. I have also had a hard time (mostly during first cut) with the grass board holding grass and clogging things up. Several years ago I attempted to fabricate a rolling grass stick based on what was pictured in L Miller’s book. It didn’t work more due to my execution of the job as opposed to the concept itself. If I were to attempt it again I would use lighter materials (aluminum maybe) and a bearing to facilitate better spinning.

Back to my original queries: Is there a reason why the guard on the outer shoe is proud (in front of) all of the other guards? If not, do you seen any reason not to grind this back? Have you heard of anyone using a few stub guards toward the outer shoe (I had virtually no problems on the inner shoe where I have 3 set up)?

It may seem presumptuous to assume that I/we could tweak these mowers that have been working so well for so long, but that is how progress happens – a conversation or idea talked about and tried. This particular mower has worked like a champ in nearly all conditions, but this wet, heavy, green second cut challenged it (and me).

We baled the last of our second cut yesterday and hope to start on 3rd if the weather cooperates. I have a few extra stub guards that I might try toward the outside shoe. Making hay in September has always been a challenge.

George

[Donn Hewes]

Hi George, I think you are right about trying things. But I am skeptical of putting stub guards on the outer bar. They really serve to run through grass that you already mowed. On the outer bar they won’t in my opinion mow well enough. I once built a center cut mower with all stub guards. For a variety of reasons, it didn’t mow very well, but one was the stub guards. As you said they don’t mow as clean as a regular guard.

How high are your cutter bars set. I like mine high all the time. On the inside I use the third out of four bolt holes for the sole plate. On the outer end you usually have two holes plus the sliding slot. I use the high hole and slide the bolt down as far as I can with it still securely fastened.

If the outer shoe point is grabbing “rats nests” or clumps of dry dead grass, shortening it won’t stop it from plugging. I am surprised there is this much difficulty with this particular problem, on second cutting hay. It is more something I would expect from over grown first cutting that was never mowed until August. How clean was the raking and baling? Leaving a bunch behind would be causing plugging next time around.

Mowing short, wet green, heavy, grass is the hardest thing to mow. Are you sure you weren’t having wheel slip issues? These can be hard to detect and a great cause of irritation. Wheel slip is worse when working in slightly soft ground. a really good mower will work great under many conditions and then suffer from wheel slip, just when the going gets really tough. Just a thought.

[dlskidmore]

I took the fence guards off my mower after reading this. Looking forward to my next deep grass work. Unfortunately it seems another nut has been lost and needs replacing before I go out again.

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