Hydraulic top link

[rasorbackq]

Looking at getting a hydraulic top link.
Is that a good idea to be used with a farmi logging winch.
Yesterday I was winching and my top link broke launching the winch towards the cable direction. My top link was a square tube steel 1/8 -3/16 wall and 1 1/2 x 1 1/2 x 24 long.
The drilled holes were a bit stretched and it just tore the end off when the tree on winch got hung up.

Can a hydraulic top link handle that amount of weight applied to the hoses / cylinder??

 

[ovrszd]

I'm always wary when I see forces put on a cylinder beyond it's hydraulic capability to create.

But then I don't know the capacity of your winch? And I don't know what size cylinder you are considering?

There are several guys on here using Farmi winches. Maybe one of them will see this thread and chime in their experiences.

 

[rasorbackq]

I'm always wary when I see forces put on a cylinder beyond it's hydraulic capability to create.

But then I don't know the capacity of your winch? And I don't know what size cylinder you are considering?

There are several guys on here using Farmi winches. Maybe one of them will see this thread and chime in their experiences.

7000 lb winch and the 2 .5 " cylinder is 21 long with a 10 stroke Think its a 1 .25 rod

 

[ovrszd]

This gets complicated. And I'm totally not the guy that can properly explain it. But here goes.

To determine what your cylinder can stand as far as extending load we need to figure how many square inches of surface there is on the piston surface, rod side of the piston. So we first calculate the surface area of the face of the piston, (pie x radius squared) 3.14 x 1.25" squared = 4.9 square inches. Then we have to subtract the surface of the end of the 1.25" rod. That is 3.14 x .625" squared = 1.23 square inches. This leaves us with 3.67 square inches of surface area on the rod end of the cylinder.

Now we need to determine hydraulic pressure of your tractor? Not sure what it develops, maybe investigate that in the owners manual or "google" it. Let's assume it develops 2000 psi.

We multiply the 3.67" of piston surface on the rod side times 2000 psi = 7,340 lbs of force. So, in theory, assuming 2000psi hydraulic pressure, your cylinder will produce 7,340 lbs of force.

Not sure where the vertical point of the winch spool is in relationship to the lower 3pt arms and the top link fastening point. For example, if it was centered between those two points you would divide your winch pull strength by 2 and end up with 3,500 lbs of pull on the top link cylinder.

You can adjust these unknowns based on your examining the equipment in question. Confused yet?

 

[motownbrowne]

Cool explanation Richard. I didn't know how that worked. Unfortunately, the top pulley of a skidding winch is above the top link. By several inches. So, the force applied to the top link will be magnified, as if by a lever, if my understanding is correct.

Rasorbackq, I think a hydraulic top link is always an improvement over a regular top link, but you may need to go with a larger cylinder. For my tractor which runs my Farmi 351 I'm going to use a 3x12 cylinder. Also, it's possible that your clutch is out of adjustment. Unless your top link was already weakened, the clutch on the winch should slip before breaking a top link.

 

[rasorbackq]

This gets complicated. And I'm totally not the guy that can properly explain it. But here goes.

To determine what your cylinder can stand as far as extending load we need to figure how many square inches of surface there is on the piston surface, rod side of the piston. So we first calculate the surface area of the face of the piston, (pie x radius squared) 3.14 x 1.25" squared = 4.9 square inches. Then we have to subtract the surface of the end of the 1.25" rod. That is 3.14 x .625" squared = 1.23 square inches. This leaves us with 3.67 square inches of surface area on the rod end of the cylinder.

Now we need to determine hydraulic pressure of your tractor? Not sure what it develops, maybe investigate that in the owners manual or "google" it. Let's assume it develops 2000 psi.

We multiply the 3.67" of piston surface on the rod side times 2000 psi = 7,340 lbs of force. So, in theory, assuming 2000psi hydraulic pressure, your cylinder will produce 7,340 lbs of force.

Not sure where the vertical point of the winch spool is in relationship to the lower 3pt arms and the top link fastening point. For example, if it was centered between those two points you would divide your winch pull strength by 2 and end up with 3,500 lbs of pull on the top link cylinder.

You can adjust these unknowns based on your examining the equipment in question. Confused yet?

Yes I was until after i read it a couple times.

 

[rasorbackq]

Rasorbackq, I think a hydraulic top link is always an improvement over a regular top link, but you may need to go with a larger cylinder. For my tractor which runs my Farmi 351 I'm going to use a 3x12 cylinder. Also, it's possible that your clutch is out of adjustment. Unless your top link was already weakened, the clutch on the winch should slip before breaking a top link.

Morning Motown , The winch was slipping but only because my wife can't pull the rope hard enough. I get there and pulled it and it snapped the top link.
Before I got there the top link hole must have bee stressed because the metal that ripped was only 1/4 left. Might just make up a new top link thicker metal and use the Hydraulic top link for other implements.
and

 

[motownbrowne]

Morning Motown , The winch was slipping but only because my wife can't pull the rope hard enough. I get there and pulled it and it snapped the top link.
Before I got there the top link hole must have bee stressed because the metal that ripped was only 1/4 left. Might just make up a new top link thicker metal and use the Hydraulic top link for other implements.
and

10-4, my friend. Just be careful with that thing. There's a thread on here where a guy was using a three point winch and tore the rear end of his tractor right off. Not a cheap repair. When you hitch onto something you can't pull one of a few things will happen: the clutch will slip, the tractor will slide, or something will break, the top link, cable, choker, or tractor. Just make sure you don't make everything so strong that the tractor is the weakest link.

 

[rasorbackq]

I like that idea Motown. Make sure the tractor is not the weakest link.
All of the above did happen . Tractor was pulled until the legs dug in. winch slipped and then the top link broke.
The top link was used for several hundred pulls over 2-3 years and yes both pin holes were oblonged. Will see if I can get a few pics today.

 

[rasorbackq]

 

[LD1]

OVRSZD is on the right track with figuring if a toplink can handle it.

These calculators make it a bit quicker for calculating Baum Hydraulics Corp :: Spec Calculator

Also correct that the height above the lift point needs to be calculated.

IIRC, the toplink on a standardized CAT 1 is 18" above the lower links. So if the pull point of the winch is 18 above the toplink....that puts double the load on the toplink. IF its 9" above, 1.5x the pull force of the winch, etc. So need to know the winch location to give you accurate data.

IF using 3000psi cylinders, hoses, etc...a 2.5" cylinder with 1.25" rod can handle 11000#. A 3" cylinder with a 1.5" rod can handle 16000#

But also gotta consider the tractor. Make the toplink the strong point.....whats the next weakest link? Have seem many pics of tractors with the toplink mount ripped right out of the casting on the tractor. Mostly due to 3PH backhoe usage.....but that winch has the ability to exert alot of force just the same.

 

[teg]

I would say NO it will not handle it. I broke my top link using a potato plow, a lot less pressure than a winch.

That top link photo doesn't look too strong. Designed to fail?

 

[ovrszd]

10-4, my friend. Just be careful with that thing. There's a thread on here where a guy was using a three point winch and tore the rear end of his tractor right off. Not a cheap repair. When you hitch onto something you can't pull one of a few things will happen: the clutch will slip, the tractor will slide, or something will break, the top link, cable, choker, or tractor. Just make sure you don't make everything so strong that the tractor is the weakest link.

That would be my concern as well. A winch can exert an infinite amount of force with proper rigging. Not being familiar with a Farmi winch I wasn't sure if they have a spade that can be lowered to the ground?? That would remove the forces from the tractor.

My Son works for a Tow Company. They have a winch box that is SSQA capable. They use it on a Kubota CTL. It has a hydraulic winch. Large spade on the front. Simply uses the CTL to be carried and powered. I've saw that 4ft cube box pull some incredible loads. Usually with the CTL hanging in the air.

Winching is very dangerous!!!

 

[Citydude]

I have a hydraulic top link on my Farmi 351 and learned to run the tractor at idle while winching. It's another way to ensure I don't overload the top link where it attaches to the tractor. When the engine lugs, it's telling me that the logs are starting to get in a jamb.

I've watched my grapple come off the ground a foot while winching at higher RPM's before and don't care to do that again. I do most of my winching up hill which compounds the force.

 

[ovrszd]

I have a hydraulic top link on my Farmi 351 and learned to run the tractor at idle while winching. It's another way to ensure I don't overload the top link where it attaches to the tractor. When the engine lugs, it's telling me that the logs are starting to get in a jamb.

I've watched my grapple come off the ground a foot while winching at higher RPM's before and don't care to do that again. I do most of my winching up hill which compounds the force.

Your conservative use is wise.

Winching is very dangerous......

 

[motownbrowne]

That would be my concern as well. A winch can exert an infinite amount of force with proper rigging. Not being familiar with a Farmi winch I wasn't sure if they have a spade that can be lowered to the ground?? That would remove the forces from the tractor.

My Son works for a Tow Company. They have a winch box that is SSQA capable. They use it on a Kubota CTL. It has a hydraulic winch. Large spade on the front. Simply uses the CTL to be carried and powered. I've saw that 4ft cube box pull some incredible loads. Usually with the CTL hanging in the air.

Winching is very dangerous!!!

They do have a blade (or in my case legs), that digs into the ground. It definitely takes some of the force off the tractor, but it's hard to know exactly how much. I know that for relatively small logs I can dig the legs in and I don't even need the parking brake. You're dead on about rigging also. My winch, and the OP's have 7700# of line pull on the first wrap. Any time in going to use a doubling block, I refrain from rigging the cable back to the tractor. 15,000# is too much! I always hook the end to a tree or other anchor.

OP, perhaps the safest thing to do would be to replace your top link with the exact same one you had. It sounds like it would be good for a few years, give you a clue before it needed replacement, and would act as a shear pin, being the first and one of the cheapest things that can fail.