Skidding winch - need bigger tractor?

dstig1 · Jun 22, 2010

So a friend of mine sent me his old skidding winch, a Farmi JL304 that is right about 30 yrs old. He used to use it on his Ford 9N for his firewood business when he was in high school and college. It had been kicked around a lot over the years and was in sad shape with the main post bent and needing bearings and a lot of cleaning. So I got the post fixed, and they also straightened out the severely bent guard that was binding up the drum. New bearings, new hardware, clean it up, fresh grease everywhere, and we took it out to give it a test run.

Got it mounted on the L3130 no problem, and only had to spend a little time adjusting the clutch to get it working correctly. So we try it out on a small log, and it works great. Then pull a large poplar and it zips it right along. So we go to grab a decent sized oak ~16" dbh, and it won't budge. It wasn't slipping the clutch it actually stopped the PTO shaft dead at full clutch engagement:shocked:. Obviously that isn't a good thing, so I quickly released the lever. Tried again a few times and same thing. It dug the winch feet in deeply but would just stall the PTO in the end.

This tells me I need more hp if I really want to run this. I don't consider this one a huge tree, so I really was surprised it wouldn't move. So the question is how much do I need? I would stick with an L-series as it is the right size overall, so I'm wondering which engine would be about right. The only thing I have for info on the winch is the label that says 30kN max 10 kN min. That doesn't do me a lot of good as PTOs are rated in KW or hp (power, not force) and besides, which force? The pull on the cable or the input? No clue.

I guess I'm just fishing for any experience others have in sizing the tractor to fit this application.

Thanks,
Dave

beenthere · Jun 22, 2010

Do you think maybe it is a clutch problem? From your description, sounds like there were more HP than ability of clutch to transfer it to the PTO.

MarkV · Jun 22, 2010

Surely there is a system like a slip clutch or shear bolt that should perform before completely stalling the PTO. I wouldn't like that at all and I am not sure more HP is the answer to the problem.

MarkV

dstig1 · Jun 22, 2010

beenthere said:
Do you think maybe it is a clutch problem? From your description, sounds like there were more HP than ability of clutch to transfer it to the PTO.

The clutch seemed to be working fine. As you pull the lever more it grabs more until you have full engagement, just like any manual clutch. We adjusted it per the label so that the drum was stationary when the lever is released and it was fully engaged with the lever pulled all the way, with some degree of slip along the way at partial lever movement. I'd say the clutch was working correctly.

MarkV said:
Surely there is a system like a slip clutch or shear bolt that should perform before completely stalling the PTO. I wouldn't like that at all and I am not sure more HP is the answer to the problem.

MarkV

It HAS a clutch, but it is manually controlled by how hard you pull on the lever/rope. As soon as I saw it stall the PTO, I released. It is a very simple mechanism. The fact that the PTO stalled and the clutch didn't slip tells me that the winch is capable of pulling more of a load than the tractor has HP to move. Thus my question about more hp... Now if the clutch started to slip, then I'd say we hit the limits of the winch.

-Dave

rbargeron · Jun 22, 2010

Hi Dave, I think your assessment of the winch clutch is right - it's doing what it's supposed to do. When tractors get loaded beyond the torque they can make, they stall. No big deal. The clutch on the winch is to gradually apply the available power, whether there's enough to do the job or not.

The 30 kn winch rating is 6,744 pounds (handy units converter here) which is similar to today's JL351 rated at 40 hp input. By proportion, the 9n has 20 pto hp (not discounting for age and wear) so it would be expected to max out at maybe 3,000 pounds, running about 1500 rpm. What rpm was it running?

radioman · Jun 22, 2010

is there anything on that winch to gear down the ratio? this would give you more turning torque with less HP.

dstig1 · Jun 22, 2010

It is geared down a lot as built. See the pic below (before the main post was straightened). The lower sprocket is the PTO shaft, the drum sprocket (back of the drum, behind the white clutch friction material) is 8-10x the diameter.

rbargeron · Jun 22, 2010

Dave - is the 9n's governor working? When the winch clutch is engaged does the throttle linkage move to give it more gas? My 8n had lots of power after the governor linkage freed up and adjusted.

BTW count the sprocket teeth to get the ratio (looks like 5 or 6 to 1). The 9n is rated at 84 ft-lbs pto torque. Multiply the 84 by the ratio and divide by the radius of the cable to the center of the drum (in feet) - to get the cable force.

I'm thinking the 9n's governor response might be worth a look.

beenthere · Jun 22, 2010

dstig1
I misinterpreted what you were saying about stalling the PTO.
Now it sounds like you are saying it is stalling the tractor engine powering the PTO going to the winch.
If that is so, then the Kub L3130 may not have enough umph in its shorts. Would think it would have more than the 9N tho.

Adiredneck · Jun 22, 2010

I apologize if I missed this in one of the posts...

How much throttle are you using? I have stalled my tractor a few times when I got my winch (to the point that the tractor ran backwards). Have learned that you cannot pull a good sized hitch without giving the tractor about 1/3 throttle.

Once I started doing this, no more stalling the tractor. The clutch on the winch will slip when I catch a root or stump (once properly adjusted).