Mowing mower deck stalling tractor

[studway]

No worries, tripleR. I'm just getting a little defensive with all the people suggesting I'm using the tractor for something it isn't intended for. It's a totally bada** deck/tractor combo that can cut through pretty much anything. I'm just looking for advice or reassurance that I'm not going to destroy the tractor by occasionally stalling it while mowing.

 

[SPYDERLK]

Your belts on a MMM/RFM serves the same purpose as a shear pin/slip clutch. I have used MMM/RFM for longer than I care to remember and hit everything from tree stumps to a boat anchor and T posts without any mechanical damage. On bigger units, I have smoked the belts and on smaller ones like 425, 2305 and BX just stalled the motor.

I don't know if you have had your blades off yet or not, but the blades are not keyed and are held only by the seventy-five to eighty pounds of torque on the blade bolts and will rotate on the shaft when striking an "immovable object".

Your deck has smooth, non toothed belts/pulleys, idler arm and then non keyed blades. Trust me, if a BX would break from hitting stuff, I wouldn't be on my second one. Now it should naturally be avoided, but there is a lot of give built into the system.

Ahh, so you're saying that the belts are slipping, enough to protect the gears and engine, just not enough for me to hear it or to see smoke. I hope that's the case.

TripleR is right. Due to the various limited slip points you will not get catastrophic overloads thru the system. One thing I think you should check tho is the mounting of the mmm gearbox. Be sure the bolts are tight. On my 54" I have had the cheap "die cast" bracket holding it break twice - the 1st time I found the factory installed bolts loose. When this breaks the gearbox moves and destroys the oil seal then the bearings and gears. Hopefully they have upgraded this bracket on your model. I finally made a steel one to replace it.
larry

 

[radioman]

I dunno studway- I think something is gonna break. Isn't it much cheaper in the long run if you mow your apple feilds more often like weekly like a regular lawn ? This way, you can see everything like a sweatshirt left behind, or branches, etc. less stress in mower, less likely to break. Why wait so long in the first place? its jut an invitation for something to break.

Isnt a ounce of prevention a pound of cure apply here ?

 

[KubieTwo]

I dunno studway- I think something is gonna break. Isn't it much cheaper in the long run if you mow your apple feilds more often like weekly like a regular lawn ? This way, you can see everything like a sweatshirt left behind, or branches, etc. less stress in mower, less likely to break. Why wait so long in the first place? its jut an invitation for something to break.

Isnt a ounce of prevention a pound of cure apply here ?

In the whole thread, some have agreed the BX MMM should regularily grind large, tough apple limbs under a finish mower without harm to tractor or mower. Others feel the task is better performed with a flail mower of bush hog. Frequency is a huge part of the equation with the mmm primarily using the engine and drive gear instead of a single, heavy blade with some mass to help break up the limbs.

Some things are designed to grind trees and some things aren't. Those that aren't will eventually break if continually used beyond design limits. A finish mower on a small tractor is designed to take some occasional shock loads as an expected part of normal use. The tractor is likewise designed to deal with some limited number of these events. His tractor so far is proving this point. However, putting the same small tractor in a commercial application where multiple sudden engine stalls from apple limb jam are part of each mowing cycle is probably outside the design parameters of intended use as some of us view it. The OP feels strongly that what he paid for the BX should have bought a machine to meet this need using the mmm. Some of you agree with that. It is his tractor and he can use is as he pleases. As current use is described, I agree with radioman that something will eventually break. When it does, the next discussion will then probably be centered around the "poor design" of either the mower or the tractor, depending on what breaks first. This same task performed with a bush hog or flail mower would not be cause for concern from anybody.

Both sides are offering their opinions sincerely, and only time will decide just how tough the mmm and tractor are.

As a point of interest, take a look at the design of something intended to grind trees....http://www.brownmfgcorp.com/Video/Brown%201.wmv

 

[radioman]

Well said kubietwo.:thumbsup:

 

[rjkobbeman]

From reading this thread, I see two concerns:

Is damage a concern when foreign objects cause engine to stall

and

Why are big sticks/minor logs stalling engine


I think the damage concern has been addressed pretty well. The tractors are tough, but if you hit something that is actually stalling the engine, the tractor is taking a pretty good beating.

In regard to the "why is it stalling" issue. One thing that I think has not been mentioned is the compounding affect of both foreign objects (sticks, logs, sweatshirt, etc.) AND the tall brush. One foot tall brush by itself may not be a problem and the occasional sticks may not be a problem, but those together are obviously too much. Don't underestimate the load of 1' tall brush.

 

[studway]

Let me address a couple of things here. I didn't say I thought this mmm should be able to grind trees and rocks. What I said was that I was suprised an expensive little tractor that has a mmm that can easily mow down foot tall grass didn't have a safety mechanism built in. I also said that anyone using this tractor could hit an immovable object. I stalled it on a sweatshirt, which could happen to any homeowner. From some of the replies, it seems it may actually have a number of design elements put in place to prevent catastrophic failure, and indeed, I haven't been able to find anyone online saying that they wrecked their BX tractor by hitting an obstacle with the mmm so it's entirely possible I'm worrying about nothing. Worst I've heard is that I might wreck the gears on the mower itself. Personally, given the upside of using it as I do, I am completely comfortable with that possiblitiy.

I have three tractors: 75hp, 40hp, and the BX. I bought this tractor for a specific purpose which was cultivating between rows of plastic mulch in a large garden. What I was looking for was the smallest, yet most powerful tractor I could find. This tractor is ideal for this task. Our garden requires less effort to weed, looks better than it ever has, and is more productive. I also use it to lay plastic mulch, to snowblow my driveway, some spraying applications, and to get firewood out in the woods with a wagon on the back. I regard it as one of the best purchases I've ever made.

I never intended to mow apple orchards with it, but when I realized how ridiculously powerful the mmm was I started using it for that purpose only after I'd already gone through with a box mower on a bigger tractor. When my sickle bar died last year I replaced it with a swisher offset rough cut which costs 1/5th the price of a cheap sickle. It works great and the BX is the perfect tractor to use it with because it's little and I can get close to the trees so the swisher can reach far under them. Sometimes, when I use this setup, I'll run the mmm at the same time. I can do an 8' swath. It's awesome.

I just mowed about half our orchards today. Box mower on the 40hp tractor, then I went in with the swisher on the back of my BX. I didn't even put the mmm on. I actually loved not using the mmm because it stresses me out worring about obstacles. Come fall when we're getting ready to open for pick your own apples I will mow the orchards with the mmm down to 3" or so and I will continue to do so once a week all season as I have each of the last 3 years. Customers comment on how nicely mowed the orchards are. Most places just use a box mower and end up with a ragged cut that is less pleasant to walk through and gets your feet wet all morning. That finish cut makes money, that's why I can live with the possibility of breakage.

Maybe a rear mount finish mower is in my future, but honestly, that would cost far more than a new gearbox for the mmm and I couldn't use it together with the swisher as I do with the mmm

. I just got an email from Kubota telling me to contact someone at my local dealer to discuss the issue. If that conversation is interesting I'll post an update.

Thanks for all the good info on my original question. I wish someone could definitively tell me I don't need to worry about it, but It seems I probably do need to worry about.

 

[radioman]

studway- you make many good points as well. With the last post you made, it really has clarified many things for us I would say.

Perhaps when talking with your dealer, you could make a point that the snowthrowers, that the cheapest and most expensive ones have a shear bolt. now go figure. While snowthrower and MMM are different implements, but It just goes to show your point that a expensive purchase should have some sort of a protection. I can't really say don't worry about it since I never stalled the engine via MMM jammed or clogged. I really don't think the gearbox is a protection to the engine.

 

[TripleR]

Studway, Interesting and informative post. I can't tell you not to worry, only that in looking at all the points of shock absorption, slippage I don't after having stalled mine and used two different ones. The MMM is essentially no different than a RFM which does not have any type of shear bolt or slip clutch, it is just under the tractor rather than pulled behind.

It doesn't sound as though you are using yours any different than I used my BX2200 and it is still running strong. I don't use my BX2660 as hard "normally" as I purchased a different tractor to take over some of the duties, but that does not mean I would be uncomfortable doing so; I would just need to sharpen my blades a little more often. Hard use will accelerate wear, but I could live with that and have.

 

[Argosy]

I'm not sure why it makes a difference if the deck or tractor fails, either way it is an expensive failure. Just the parts to repair the deck were over $400. The entire gear box has to be disassembled, there are 3 bevel gears that have to have the depth set, everything is held in place with snap rings and there are only two access openings. It's tight, accurate work, not a quick job and it's not a cheap job if you pay to have it done. Dealers won't stock those parts so you will wait. I've got to imagine the total bill was one of those 'have a seat' moments as I was told it was probably just a bad seal.

Most importantly, my point wasn't to say the deck will fail first. The direction of this thread seemed to be the belt would act as a safety device and I wanted to counter that. Only the outer blades are belt driven, the center blade is direct drive through the gear box. Anything you hit with that blade is transferring shock back to the tractor.

I don't believe (short of an actual safety device) you will find individual components of a drive line seriously over or under engineered, they will all be designed to same specs. IMHO any part in the drive line could fail, don't count on my example as assurance the weak link is in the deck. I merely meant to say that you CAN do serious damage by hitting objects.