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  1. #51
    Veteran Member vtsnowedin's Avatar
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    Default Re: Tipped my BX25 FEL & BH on its side - what precautions to take before starting en

    Quote Originally Posted by Mace Canute View Post
    The premise that the lines define the tractors "stability baseline" is incorrect. It would hold true ONLY if you had a solid mounted front axle with absolutely no provision for it to pivot. To my knowledge, no tractor is built that way.

    I hesitate to try this as it is like arguing evolution but...
    Do you really think a tractor can tip over without the low side front wheel coming to the limit of the front pivot play and at that point in time the upward resistance of the ground on that wheel is not applied as a reaction force upward times the distance that wheel is set out from the center of rotation?
    Also do you really think that paper from that source got published without somebody really good at physics and statics checking the math?
    People love their old tricycle front tractors for the nostalgia, and they were a great leap forward from what people were using before them, but stability was never their strong suit and we should all be glad they don't make them that way any more.

  2. #52
    Veteran Member xring100's Avatar
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    Livingston County, Michigan
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    Kubota M8540

    Default Re: Tipped my BX25 FEL & BH on its side - what precautions to take before starting en

    Quote Originally Posted by vtsnowedin View Post
    I hesitate to try this as it is like arguing evolution but...
    Do you really think a tractor can tip over without the low side front wheel coming to the limit of the front pivot play and at that point in time the upward resistance of the ground on that wheel is not applied as a reaction force upward times the distance that wheel is set out from the center of rotation?
    Also do you really think that paper from that source got published without somebody really good at physics and statics checking the math?
    People love their old tricycle front tractors for the nostalgia, and they were a great leap forward from what people were using before them, but stability was never their strong suit and we should all be glad they don't make them that way any more.
    Well said this document looks like its the equivalent of a published SAE paper, where you have multiple Engineers writing / checking the work. Most with masters degrees some PHD's all with extensive backgrounds in applied physics, statics/dynamics, kinematics etc. The fundamentals explained in this document look to be very solid. Coming from a guy who holds a B.S. in Mechanical Engineering From GMI/Kettering University i would not bet against the publishing.

    Dave

  3. #53
    Silver Member
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    Dewey, AZ
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    Kubota B7800

    Default Re: Tipped my BX25 FEL & BH on its side - what precautions to take before starting en

    A couple of years ago, a local rental yard sent out a B26TLB and their customer rolled it. Wrapped a chain around the BH control tower and bucket cylinder linkage. Bent the crap out of the tower. Then they tried to start it. When it was brought into us, it had one **** of a miss. #2 cylinder was low on compression. Told rental yard that it had a bent rod. Sure enough, bent rod. Didn't hurt anything else. It could have been a LOT worse.
    Mike
    B7800 "Drowned Rat"
    It spent 6 weeks under water

  4. #54
    Veteran Member GolfAddict's Avatar
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    SE Minnesota
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    Kubota BX24; John Deere 4020

    Default Re: Tipped my BX25 FEL & BH on its side - what precautions to take before starting en

    Quote Originally Posted by panchohughes View Post
    I am not sure I understand the issue. I have a 60" mid-mower. Is the issue due to tires being too close to the deck rollers at the rear corners of the deck or something?
    Yes, that is the issue. I understand you can use spacers with the 60" because you have the clearance (that you described) to move the rear wheels out without hitting those deck rollers.

    With the 54" deck, those rollers are quite close on each side to the rear wheels. Looking at my set up, and having read threads here, etc., I understood you couldn't add spacers with a 54" deck because there just isn't room. However, I'm going to do a little more reading and actual measuring now based on willi67's info below...

    Quote Originally Posted by willi67 View Post
    Howdy, you are correct about 2" spacers with the 60" deck, but you can also have spacers with a 54" deck .. 2" LHS 1.5" RHS check page 4 of this thread http://www.tractorbynet.com/forums/k...cers-work.html

  5. #55
    Super Member radioman's Avatar
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    Ontario, NY
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    Kubota BX24

    Default Re: Tipped my BX25 FEL & BH on its side - what precautions to take before starting en

    forget the spacers and 3pt pivot stuff. where is OP? did he pull glow plugs out yet? was he able to turn engine over by hand to see if it rotate ok?

  6. #56
    Platinum Member
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    WI
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    '13 Yanmar Lx4100

    Default Re: Tipped my BX25 FEL & BH on its side - what precautions to take before starting en

    For you guys that roll your tractors. No need to pull glow plugs out right away, rotate the engine over with a rachet if you can get to the crankshaft. If you have some major resistance other than normal compression then you know you have to procede further or wait untill the oil can drain back through the rings.

  7. #57
    Veteran Member RaydaKub's Avatar
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    Kubota BX2230

    Default Re: Tipped my BX25 FEL & BH on its side - what precautions to take before starting en

    Quote Originally Posted by vtsnowedin View Post
    I hesitate to try this as it is like arguing evolution but...
    Do you really think a tractor can tip over without the low side front wheel coming to the limit of the front pivot play and at that point in time the upward resistance of the ground on that wheel is not applied as a reaction force upward times the distance that wheel is set out from the center of rotation?
    Also do you really think that paper from that source got published without somebody really good at physics and statics checking the math?
    People love their old tricycle front tractors for the nostalgia, and they were a great leap forward from what people were using before them, but stability was never their strong suit and we should all be glad they don't make them that way any more.
    I'll try one last time. Let's say your front axle pivots by 10 degrees either direction (no idea what they really do). You are on a side hill of 25 degrees. Assuming a plane for a hillside (perfectly flat, no rocks or holes). At the time you are driving along, your tractor is going to feel like the left diagram because of the pivot. Sitting in the seat, you won't feel the front axle's contribution to stability until the rear wheel tips an additional 10 degrees, meaning the seat is tilted at 35 degrees (still on that 25 degree hill). When your rear wheel is 10 degrees in the air, suddenly you have changed diagrams to the right one. Ultimately, there is an additional margin of safety. But you had to tilt 10 degrees more than the hillside to find it. Adding spacers to the front axle won't change that additional 10 degree tilt the body of the tractor must go through before the front axle's contribution is relevant. In the mean time, the entire footprint of the tractor with respect to gravity (straight down) has gotten more narrow.

    Safer? Absolutely, no question. Pucker factor? Just about dead even.

  8. #58
    Veteran Member GolfAddict's Avatar
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    Default Re: Tipped my BX25 FEL & BH on its side - what precautions to take before starting en

    I agree with Ray. The trapezoid picture of a wide front tractor is a little deceptive. A wide front and narrow front tractor have the same exact triangle shape when they are just sitting there.

    With a narrow front tractor, the point of the triangle is at the centered front tires. With a wide front tractor, the point of the triangle is at the front axle pivot. Even when the tractor is on a side hill, the wide front tractor still has the same triangle shape. It is important, but maybe difficult, to realize that it isn't until you have actually started tipping the tractor over, all the way to the point of front axle hitting the pivot stop (upper rear wheel is off the ground now), that a wide front tractor then becomes the trapezoid shape.

    And actually, it really isn't a trapezoid shape even then. It is now a new triangle with the two front wheels and the low side rear wheel. You are tipped over at this point, just not rolled on over.

    This can/should be "safer" as long as you don't have enough momentum built up to go on over. With a narrow front at this same tipping point, it became a straight line (front wheel, lower rear wheel) rather than a triangle and you're very likely screwed...

    I think it's very easy to think of a wide front tractor having this trapezoid shape (like other four wheeled vehicles) and it really doesn't.

  9. #59
    Super Member Gary Fowler's Avatar
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    2009 Kubota RTV 900, 2009 Kubota B26 TLB & 2010 model LS P7010

    Default Re: Tipped my BX25 FEL & BH on its side - what precautions to take before starting en

    Quote Originally Posted by RaydaKub View Post
    I'll try one last time. Let's say your front axle pivots by 10 degrees either direction (no idea what they really do). You are on a side hill of 25 degrees. Assuming a plane for a hillside (perfectly flat, no rocks or holes). At the time you are driving along, your tractor is going to feel like the left diagram because of the pivot. Sitting in the seat, you won't feel the front axle's contribution to stability until the rear wheel tips an additional 10 degrees, meaning the seat is tilted at 35 degrees (still on that 25 degree hill). When your rear wheel is 10 degrees in the air, suddenly you have changed diagrams to the right one. Ultimately, there is an additional margin of safety. But you had to tilt 10 degrees more than the hillside to find it. Adding spacers to the front axle won't change that additional 10 degree tilt the body of the tractor must go through before the front axle's contribution is relevant. In the mean time, the entire footprint of the tractor with respect to gravity (straight down) has gotten more narrow.

    Safer? Absolutely, no question. Pucker factor? Just about dead even.
    What you said is somewhat true but not totally correct and 10 degrees seems about right for the amount of tilt in the front axle. (By the way the 2-3" was clearance measured at the junction of tractor frame and axle) The thing is that if you are running on a 25 degree slope, your pucker factor is already way past maximum. Dropping the front wheel into a hole is not going to change the seat angle (remember the swivel front axle of 10 degrees), it wont change till the rear wheel hits the hole and if it truly does throw the angle to 35 degree tilt, with any small amount of forward momentum, it will likely be enough to roll the tractor. It doesnt take much of a bump/dip on the rear when you have a slope that large to kick the CG with enough force to roll it.

    The thing is rather than argue on the merits or does the wide front help, concentrate on operating the tractors in a safe condition to start with. I see highway mowers side mowing on slopes that I wouldnt want to be on going up and down but apparently they are safe to mow as I havent seen a mower on its back. DO I WANT THEIR JOB, HECK NO.
    As for how far will the tractor tilt before going over: ever see that video that was posted on TBN of the tractor hitting the ramp and turning up on 2 wheels and driving thru some obstacle course, that looks like 45 degrees to me and perfectly in balance and way more than I would ever imagine getting into.
    2010 LS P-7010C 20F/20R gear tractor & FEL, 2009 Kubota B 26 TLB, RTV 900 Kubota,17 foot Lund boat with 70HP motor, 2012-20 ft 12k GVW trailer, 2011- 52" Craftsman ZTR mower, 2013 Ferris Zero Turn, 3 weed whackers, pressure washer, leaf blowers, 7 foot bush hog, 8 foot landscape rake , 8 foot 3 PH disc, 2 row cultivator, 350 amp Miller AC/DC welding machine and all the tools needed to keep them all repaired and running.

  10. #60
    Veteran Member RaydaKub's Avatar
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    Default Re: Tipped my BX25 FEL & BH on its side - what precautions to take before starting en

    Basically, I got into this discussion because I didn't want the OP to get a false sense of security by adding spacers and thinking all was going to be well.

    I measured my hillside last summer with my BX. I was pretty high on my pucker scale and stopped to measure it with my table saw protractor and a level. Somewhere around 22 degrees. But it isn't quite so bad without the FEL. So I just used 25 degrees in my previous post.

    GolfAddict, ==> And actually, it really isn't a trapezoid shape even then. It is now a new triangle with the two front wheels and the low side rear wheel. You are tipped over at this point, just not rolled on over. <== That's the part I could envision and disagreed with, but couldn't quite verbalize it. Thanks.

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