3 point lift capacity

[Whiskey]

Tractor nuts:

Got a question that I'm just not understanding. Lets take the two tractors that I'm looking at, the JD 790 and NH TC30. JD'S 3 point lift capacity states 815 lbs 24" behind the like ends and the TC30 is 1635 24" behind the link ends.

OK, heres the question most of the heavy and medium duty 5' rotary cutters are in the 1000 and some change weight, will the JD lift it and is it taxing on the tractor over the life of the tractor meaning stress on the lift.

when I do a search on the JD 790, most of the owners are using a 5' cutter so what is it I'm not understanding here /forums/images/graemlins/confused.gif

Whiskey

 

[Anonymous Poster]

Whisky,

I just went throught the thought process of choosing a rotary cutter for my B2910 Kubota which lifts 1,300 lbs 24 inches back.

Bottom line is that a medium duty rotary cutter will not make sense on my tractor. Not only because my tractor would struggle to lift it, but because my tractor only weighs about double what the medium duty rotary cutter does. THe danger here is if I could lift it, when moving in the transport position I could be doing wheelies a lot and losing steering control.

So I decided that a standard duty cutter, maxing out at about 600 lbs, makes sense for me.

You have to consider the leverage effect of something heavy hanging back well beyond the 24" poisition. That means that less weight being farther back can exceed the lifting capacity of your 3Ph.

 

[Mosey]

When I was shopping for a tractor I had it narrowed down to the JD790 and the TC29 (they didn't have the TC30 then). One of the things that made me pick the TC29 was the 3pt lift capacity, which is the same as the TC30. I was amazed at how much less it was on the JD790.

I agree with Henro that you don't need a heavy duty bush hog for a JD790 or TC30 size tractor. I have a 5' King Kutter which weights about 550 lbs. My 6' LandPride finish mower weights about 650 lbs. My tractor handles both easily.

The thing to consider is if 815 lbs is enough if you get a boom pole or rear scoop. I can lift my 30" rear scoop full of wet clay with no problem. I'm not sure the JD790 could do it. I've also used the 3pt to pull out posts, which a lesser 3pt lift capacity might not have been able to do. I also have a 3pt pallet mover and I've always been able to lift it. That extra several hundred pounds of lift capacity is very handy!

 

[timb]

Whiskey,

Another good guideline to how much implement you could expect to actually safely lift - considering both weight and how far out back it hangs - check the owners manuals regarding ballasting.

From what I've seen, it looks like you are not supposed to "officially" hang anything heavier than your SMV sign out back without some sort of front ballast to keep the nose below the horizon. JD uses an "implement code" system - the implement literature gives you a number (say "82") that's based on both actual weight and physical implement size. The tractor owner's manual then tells you how much added weight is needed on the front end for off-setting balance - depending on whether you have MFWD or 2WD. I'll bet the other mfgs. do something similar.

While it sounds like most owners here either keep their FEL on - or don't worry about front ballast at all - ballasting is a subject covered extensively in the factory literature.

And as an FYI example - that "82" is the number for a 1000 lb. 6-foot JD MX6 medium duty cutter - not all that much heavier than a typical medium duty 5-footer (the MX5 weighs 850 lb). The JD 4510/4610/4710 manual specifies adding 700 lbs of "suitcase" weights (out of a maximum 840 lb) to the front end to offset it - and that's on a 3500 lb tractor!.

Meaning that despite the 2,500 lb @ 24" 3ph rating on those large-frame JD's - that 1000 lb mower is getting near the "safe" implement max. because of where the weight hangs.

 

[JimMc]

The problem with a cutter on the 790 is not so much the weight taxing the tractor as it is keeping the front wheels on the ground. Our standard 20 Series 60" cutter will pull the front wheels off the ground when lifted on a 790 with 2WD and no FEL. With 4WD and weights it is marginal. Add the FEL and it's still dicey when going uphill. The 790 is actually the reason we had to come out with our 15 Series. This condition is made worse with the addition of a quick hitch, because the weight of the implement is moved further behind the rear axle. Take a look at how far the link ends are behind the rear axle compared to other tractors and you get one of the reasons the 790's capacity is less.

So, for use with the 790 keep cutter weight close to the tractor, use a cutter under 500 lbs. and leave the FEL on, or prepare to steer with turn brakes. /forums/images/graemlins/shocked.gif

Now the good news. PTO HP is not a problem. The 790 will run a 60" cutter all day and do a great job. With the correctly sized (weight not width) cutter, it will also handle great.

 

[Buck]

</font><font color="blue" class="small">( So I decided that a standard duty cutter, maxing out at about 600 lbs., makes sense for me.)</font>

Very good point. My view is that designing a tractor for 2000 lb. lift capacity ought to be relatively easy. Going out on the market with a tractor that has capacities matched to its dimensions and horsepower is not. I have a 790 with the inferior specs. I have never had a problem with mowers, loaders, 740 lb. tillers or other issues. I have had several problems with safety. I appreciate that my CUT is tailored nicely to my tractor.

Buck