Hydraulics questions

woodlandfarms · Jun 25, 2007

Charlie_Iliff said:
I've never gotten a bum steer from Terry, so I suspect there's a communication problem somewhere. If you ever want to test that thesis, make sure there aren't any innocents downhill of you.

Charlie... Watcha' thinkin' on this? That the 1850 with doubles on will go over with 1200lbs at 6ft @45 degrees? Not surprised on communication. I generally only listen to what I want to hear... my career has done much damage to me...

Charlie_Iliff · Jun 26, 2007

woodlandfarms said:
Charlie... Watcha' thinkin' on this? That the 1850 with doubles on will go over with 1200lbs at 6ft @45 degrees? Not surprised on communication. I generally only listen to what I want to hear... my career has done much damage to me...

I don't know whether it will go over or not in smooth slow conditions. I haven't done the calculations with precise numbers. In that condition, however, there would be zero room for error. All the weight would effectively be concentrated on the downhill tires. A minor undulation or slide accelerating that high load would greatly magnify the rollover tendency, so I wouldn't bet you'd stay upright. I only have single tires on the 1845. I have the post pounder, and wouldn't want to do any significant side-hill movement with the weight up. When it feels a bit tippy, I believe it. Similarly, on any slope, even fairly gentle, a high bucket isn't static rollover torque if you're moving. A little bit of rocking and you may lose it. Even with the duals, I'd only go on anything steeper than 30 degrees with the big mower on the deck. Ratings are great, but I'm chicken.

I'll bet in every forum on TBN you'll find a report of someone who went over with a loaded bucket high -- some on the flat.

cqaigy2 · Jun 26, 2007

Charlie_Iliff said:
I don't know whether it will go over or not in smooth slow conditions. I haven't done the calculations with precise numbers. In that condition, however, there would be zero room for error. All the weight would effectively be concentrated on the downhill tires. A minor undulation or slide accelerating that high load would greatly magnify the rollover tendency, so I wouldn't bet you'd stay upright. I only have single tires on the 1845. I have the post pounder, and wouldn't want to do any significant side-hill movement with the weight up. When it feels a bit tippy, I believe it. Similarly, on any slope, even fairly gentle, a high bucket isn't static rollover torque if you're moving. A little bit of rocking and you may lose it. Even with the duals, I'd only go on anything steeper than 30 degrees with the big mower on the deck. Ratings are great, but I'm chicken. I'll bet in every forum on TBN you'll find a report of someone who went over with a loaded bucket high -- some on the flat.

I wouldn't think anybody would make a claim about stability for the reason's you just stated. You might be able to make a claim about the load up all the way on a 45 degree hill if you got rid of those variables and were just standing still.

SpringHollow · Jun 26, 2007

When I talked to Terry, he also said they limited the lift capacity on the slop mowers so they could be used on side hills but I took it to mean that you could carry a full bucket load down low across a side hill. I just would not have even thought that you could do it up high so I did not ask which scenario he was referring to.

Ken

ponytug · Jun 28, 2007

I just spoke to Terry, whose comments, while printable, were along the lines of 'you would be insane to try it'. He said that the lift height/weight were level ground numbers. The transverse slope angle was for mowing, or the load at ~6" off of the ground. Definitely not with the load high in the air.

Drive safe!

Peter

ksimolo said:
When I talked to Terry, he also said they limited the lift capacity on the slop mowers so they could be used on side hills but I took it to mean that you could carry a full bucket load down low across a side hill. I just would not have even thought that you could do it up high so I did not ask which scenario he was referring to.

Ken

woodlandfarms · Jun 28, 2007

Different than what I heard. Well then, I am indeed going to up the lift of the front. What a bunch of BS to have a 65 hp tractor with 1200lbs of lift... dumb design...

J_J · Jun 28, 2007

woodlandfarms said:
Different than what I heard. Well then, I am indeed going to up the lift of the front. What a bunch of BS to have a 65 hp tractor with lbs of lift... dumb design...

Did you ever consider the fact that your cylinders might be strong enough to lift that extra weight right now. That 1200 lb limit they set for your machine, may have been for safety reasons. Go to Surplus Hydraulics, and click on tech help, and input the figures for your current cylinders, and then put in figures for larger cylinders, and check the results. It just might be that any thing over 1200 lbs, would pick up the rear end. So, is there a way around that. Yes, add more weight to the rear end. If you do install larger cylinders, you will probably have to add some weight anyway.

J_J · Jun 28, 2007

J_J said:
Did you ever consider the fact that your cylinders might be strong enough to lift that extra weight right now. That 1200 lb limit they set for your machine, may have been for safety reasons. Go to Surplus Hydraulics, and click on tech help, and input the figures for your current cylinders, and then put in figures for larger cylinders, and check the results. It just might be that any thing over 1200 lbs, would pick up the rear end. So, is there a way around that. Yes, add more weight to the rear end. If you do install larger cylinders, you will probably have to add some weight anyway.

I went ahead and inserted some figures into the calculator.

Bore = 2.5 in
Rod Diameter = 1.25 in
Pressure = 2500 psi

Lift force with that setup, would be over 12,000 lbs, and then, you have two of those cylinders.

Now keep in mind that you have a fulcrum effect with the cylinders, and lift arm setup, and wheel placement. Other wise, what is the weight you can lift at a certain distance.

MossRoad · Jun 28, 2007

woodlandfarms said:
Different than what I heard. Well then, I am indeed going to up the lift of the front. What a bunch of BS to have a 65 hp tractor with 1200lbs of lift... dumb design...

Not a dumb design at all. It is a specialized machine. It is a slope mower first, that can also do light front end loader work. It needs that HP to get up those slopes while powering a mower. There isn't a conventional tractor that can do those slopes safely for the price. If you wanted more lift capacity, perhaps you should have gotten a different model.

woodlandfarms · Jun 29, 2007

Wow, interesting replies. Let me firs say to those who I may have offended about bashing PT that there is no bash... I bought my tractor to deal with my slopes first and foremost. So, I am very happy with it in that account. As a matter of fact I am tickled pink with the tractor. It has done everything I have asked of it, except for lifting the occasional heavy item. As for the front end lift, I can live with it, but as I said, I am quite surprised at its limit, considering the weight of the tractor, as well as the HP.

I had understood the design decision to be that it was related to the ability to lift weight on slopes. Now I am told I am wrong...

So, what is the rational to take a 65HP tractor, who's lighter and less HP brethren (the 1445) lifts 750lbs more. If the tractor will go over extended then why not design the tractor to lift at its limits? How is that not dumb to not maximize the potential of a vehicle? What would PT have lost financially to swap the front arms out for the 1445 arms and up the hydraulics? $200 for the upgrade if that I would guess... On a $30K tractor?

As for this my initial question, it was really about the actuality of this pursuit. I was looking for advice on how I would go about upgrading the load ability. In my head, and not on paper, were questions on how do you rate a cylinder, how would you upgrade it? What is the potential downside of upgrading the lift capacity? Does the current lift controls need to be upgraded? Does my draft control and float control need to be adjusted?

If we can start this thread over with this sort of questions in mind I would love to glean everyone's experience and advice. I am a practical person, but hydraulics and the mechanics that govern them were subjects I chose to ignore or sleep through in college.

Again guys, don't take anything I say too personal. It is just a tractor and I am just looking to improve a well designed machine into my personal version of a great machine...

Carl