3PH Lift Capacities?

73jeep · Oct 27, 2005

When manufacturers list different places where their model's lift capacity is measured from, where exactly are they talking about?

Example:
MF 1523, AGCO st24A, and Challenger m225B are all pretty much the same model. Here are their specs....

--------------@ hitch----24"behind----24"behind-------------------
model------- point------hitch point----hitch balls------------------
MF1523-------1190--------------------------------------------------
ST24A--------1213--------882--------------------------------------
M225B--------1190-------------------------591---------------------

My question....Is the 24"behind hitch point a different place than 24" behind hitch balls? And if they are talking about the same place, why would the AGCO be almost 300lbs stronger there and about the same at the hitch point?

hayden · Oct 27, 2005

Lift point and hitch balls are the same location. It's the point where the draw bars attach to the implement's lift pins. The lower lift capacity at 24" behind the lift point is due to the lever arm effect. It can lift less and less heavy implements as the implement's center of gravity is further and further behind the lift point.

73jeep · Oct 27, 2005

A 60" Woods RD finishing mower weighs 605 lbs.. Would this be pushing the limits on the MF 1523 if lift capacity is 591 lbs. 24" behind ball ends? (Even though @ hitch point = 1190 lbs.)
Or would this tractor-mower combination still be safe?

Soundguy · Oct 27, 2005

My guess is that the lift arms may be a limiting factor.. even though those 2 tractors list nearly same # at lift point.. but different #'s behind lift point.

Tractor weight may also play a role.. the farther back the weight.. the more leverage it has ont he front of the tractor, using the rear axle as the fulcrum.

Soundguy

jinman · Oct 28, 2005

( A 60" Woods RD finishing mower weighs 605 lbs.. Would this be pushing the limits on the MF 1523 if lift capacity is 591 lbs. 24" behind ball ends? (Even though @ hitch point = 1190 lbs.)
Or would this tractor-mower combination still be safe? )

You may find you need to add front weights to lift the mower safely.

To calculate the lift of the RFM, not all of its weight is distributed behind the 24" lift point. If you consider the lift maximums and the RFM, how much weight is behind the point 24" out from the lift balls and how much is between the lift balls and 24" out? My guess is that on a finish mower, the weight might be distributed 40% in the first 24" and 60% in the second 24". With that geometry and the toplink carrying some of the weight, I think your 3PH will carry the finish mower. The numbers may even be reversed with 60% in front and 40% behind the 24" point.

MessickFarmEqu · Oct 28, 2005

This same principle also applies to the loader. As I recall Massy does list bucket center (not pivot pin) measurements for the loader - many companies do not. This is really important because you NEVER lift anything from where the pin is at and your capacity is always lower than that deceptive figure that some companies try to push.

73jeep · Oct 28, 2005

I guess I could just go to the Ferguson/Kubota Dealer(who also carries Woods products), and test it out. Even if I use front weights, and can lift the mower, will it still shorten the life of tractor/hydraulic parts by stressing them to their limit each time I use it? Or should I settle for a lighter RFM than the Woods? (I've always heard excellent things about Woods!)
And other than the weaker lift capacity, I like the MF 1523 better overall than its competitors; for me anyway. My plans were matching a MF 1523 to a Woods RD6000 RFM(which weighs 605 lbs.). I don't want anything that's going to be too hard on the tractor though.

hayden · Oct 29, 2005

You basically need to figure out how far behind the lift point the implement's center of gravity is. With a mower, the blade spindle location should be a good estimate of the location of the center of gravity. This is easier with a single spindle rotary cutter (brush hog) than a multi-spindle finish mower. I'd pick the mid-point between the spindles jut to keep it simple.

With my woods rotary mower, the center of gravity is much further back than 24". I'd estimate somewhere between 3' and 4'. With a finish mower, it would be closer to 24" from what I've seen, but it seems unlikely it would be closer than 24". I'd guess the mower is too heavy.

73jeep · Oct 30, 2005

( ) I'd guess the mower is too heavy. ( )

Now that's NOT what I wanted to hear!!

Just kidding!! Thanks for the input!

hayden · Oct 31, 2005

This sort of thing sure would be easier if implement manufacturers specified the "24 inch behind the lift point equivalent weight" to match the lifting specs of most hitches.

It will probably happen about the same time the hot dog and bun producers agree on how many to put in a package.