Skidding winch

[John_Mc]

You don't have to increase the tractors RPM, the tractors governor kicks in and "maintains" the RPM you have set.

The added fuel from the governor, increases the torque that the engine puts out, to compensate for the added load.

SR

Yes, but...

The torque available from the tractor's engine decreases when operated below the peak torque RPM. So the governor will only keep up up to a certain point. If you are below your tractor's max torque RPM, increasing the RPMs will increase max available torque as well.

 

[CobyRupert]

So would you say that with a 6k electric winch as wraps increase the power cant be increased so therefore you loose pulling power? But on a 6k pto winch as the wraps increase to maintain pulling power at 6k, increasing the tractor's rpm will maintain 6k pulling power or until cable breaks?

Be careful of the terms. 6k is the pulling force. How fast (ft/s) you move the load (while pulling at that force) is Power.

Think of Power (as the product of) = Torque (Force) x Speed.

On a pto winch, it’s not that you would increase tractor’s rpm to maintain pulling Force. You’d increase tractor’s fuel to increase Power at the same rate that the cable Speed is increasing (on the reel) to maintain a constant 6k Force.

(I.e. Change in Power has to be proportional to change in Speed if Force is to be constant.)

 

[Oldpath05]

So.....letç—´ say tractor has a constant (fixed) rpm input to winch.
This makes a constant reel rpm, and would be a constant cable speed, but as the effective reel diameter increases the cable speed increases.
This means more power is required from tractor.

While more tractor power is required, itç—´ still at same PTO speed, this mean the torque that is passing through winchç—´ clutch is increasing. Clutch limits the Torque passed to drum.
Clutch also limits the power TO the drum, when tractorç—´ PTO is operating at a fixed speed.
Power OUT of the drum (cable) is also fixed. (Because power in =power out, ignoring losses ) Thus, if the cable pulling Power stays constant, the torque (pulling Force) decreases as the pulling speed increases (as effect reel size increases).
That makes sense and as expected.
And confirms that the pulling rating (in lbs) is dependent on if itç—´ first cable turn on reel or last.
And has little to do with the rpm your running winch at.

"letç—´ say tractor has a constant (fixed) rpm input to winch."<<<<No I cant say that because I always increase rpm on big logs to increase pulling power or my tractor will stall, that's why I think electric winches are different. My winch is rated for 3000 kg= 6613.868 lb, I round it off at 6k, so if clutch is not slipping because I got grease on clutch dics, to me that means at full throttle witch is ether 2500 or 3000, my winch should produce a 6k pulling force regardless of wraps til my 8 mm cable breaks or tractor stalls which it has before. So I'm still thinking I have 6k regardless of wraps.

Now if I had 10k pto winch my tractor motor wouldn't produces that much pulling power on a full wrap drum but maybe if drum had just a few wraps it would.

I think I got 6k pulling here at idle my tractor would stall. Big Hemlock log pt.3 - YouTube

 

[Jstpssng]

Sometimes I prefer to let it stall rather than have something else give up first. I'd much rather restart than break my winch or tractor.
Not so much when I had my 275 though, if I wasn't careful when the log snubbed up it would restart the tractor... running backwards.

Your L3400 handled that hemlock well. That was a heavy tree, probably half of the weight of your machine. :thumbsup:

 

[CobyRupert]

"let’s say tractor has a constant (fixed) rpm input to winch."<<<<No I cant say that because I always increase rpm on big logs to increase pulling power or my tractor will stall, that's why I think electric winches are different. My winch is rated for 3000 kg= 6613.868 lb, I round it off at 6k, so if clutch is not slipping because I got grease on clutch dics, to me that means at full throttle witch is ether 2500 or 3000, my winch should produce a 6k pulling force regardless of wraps til my 8 mm cable breaks or tractor stalls which it has before. So I'm still thinking I have 6k regardless of wraps.

Now if I had 10k pto winch my tractor motor wouldn't produces that much pulling power on a full wrap drum but maybe if drum had just a few wraps it would.

I think I got 6k pulling here at idle my tractor would stall.

I mean that once you set hand throttle and get off tractor to operate winch, the PTO speed is relatively fixed from that point on.

So yes, more “power” is being transmitted when you raise rpms in the sense that you’re pulling the load faster, but I think the maximum pulling force is the limit of the winch’s clutch, no matter what rpm it’s turning at.
This maximum force, that the clutch can transmit is converted into a cable pulling force (and cable speed) that varies depending on the diameter of the drum.

 

[Sawyer Rob]

So yes, more 闖殪wer is being transmitted when you raise rpms in the sense that you豎*e pulling the load faster, but I think the maximum pulling force is the limit of the winch逞ｴ clutch, no matter what rpm it逞ｴ turning at.

Your winch (each model/size of winch) has a HP rating "input", that it takes to get MAX out of your winch. Increasing your RPM beyond the minimum the winch needs for max power, will NOT increase the power of the winch.

To get MAX out of MY winch, it takes 20HP... Putting it on a 40HP will not make the winch pull more, once you put 20HP into my winch, that's all it can use to get max out of it. Like was said, putting more into it will probably just slip the clutch.

The confusion here is, at what RPM does YOUR tractor make the minimum HP your winch needs to make max pulling power?

My tractor being bigger with REALLY GOOD low end torque, doesn't need to spin very fast to make 20HP...

SR

 

[John_Mc]

Sometimes I prefer to let it stall rather than have something else give up first. I'd much rather restart than break my winch or tractor.

Not really an issue with a properly designed logging winch. The clutch slips before you put enough torque on the winch to damage it or your tractor.

 

[CobyRupert]

The confusion here is, at what RPM does YOUR tractor make the minimum HP your winch needs to make max pulling power?

SR

Yes, well said. But I'd substitute the word torque for HP in your statement.

When the tractor's torque output is less than the torque the winch's clutch slips at, then it's a different ball game, and stalls can occur.
This gets into the rpm/torque curve of the motor, which I was ignoring for the sake of simplicity. But you can't ignore this if the tractor's low end torque doesn't exceed the setting of the winch's slip clutch.

So yes, in this scenario, increasing rpms will increase the torque and pulling force up to the what's allowed by the slip clutch. -as John_Mc noted above. Increasing power and rpms beyond that only increases cable speed.

..and of course, having a fixed maximum amount of torque through the slip clutch means the "maximum" pulling force/torque at the cable will decrease as speed increases as the cable drum diameter grows.

I looked at Wallenstein info to see how they rate their winches (first cable turn on roll, middle, or last turn?). Didn't find an answer but found that the cable speed they list is a range that varies 2.33:1. Wow! I'm pretty sure that tells me that maximum cable pulling force (torque) will also vary by 2.33:1 from first turn on roll to last.

 

[John_Mc]

FWIW - my bet is that Logging winches are rated for the pulling force while the cable is on the first layer of winding. That's the most easily reproduced situation. Rating when the drum is full would also penalize a winch which shipped with a longer standard cable, since the advertised specs would look wimpier.

EDIT: Just heard back from Hud-Son, the US distributor of Uniforest logging winches. These winches are rated with half of the standard cable wound onto the drum. I find that interesting, since they usually ship with 230 feet of cable, standard. Most other brands ship with shorter cables.

 

[Oldpath05]

Does anyone use 230' of cable? I'd cut that in half, mine holds around 140' and that's more then enough. Sometimes when I'm winching at low rpm the tree will catch on something and stalls my tractor and some how the motor starts running backward, I have to shut it off and re-start, weird and sounds different to, that ever happen to anyone else?

 

[Jstpssng]

Not really an issue with a properly designed logging winch. The clutch slips before you put enough torque on the winch to damage it or your tractor.

I once almost pulled my 275 over backward with my beat up old Fransgard. I was watching the twitch and trying to get it to come up over a stump. Something didn't sound right so I looked at the tractor and backed off just before it got the the point of no return... the closest I've ever come to flipping. Granted that winch was old and probably out of spec but still...

Does anyone use 230' of cable? I'd cut that in half, mine holds around 140' and that's more then enough.

I did last winter. By March with all of the snow it was easier to drag a tree down trails which I hadn't kept broken out. I had my snatch block about 100 feet back from the tractor, and ran the cable from that off to the trees on the side in the herringbone pattern.

Sometimes when I'm winching at low rpm the tree will catch on something and stalls my tractor and some how the motor starts running backward, I have to shut it off and re-start, weird and sounds different to, that ever happen to anyone else?

My 275 did as I stated previously. My neighbors tell me that their 235 Timberjack will do the same thing. It sure does sound different, and all of the idiot lights and gauges on the dash do funky things.

 

[guitarman]

Does anyone use 230' of cable? I'd cut that in half, mine holds around 140' and that's more then enough. Sometimes when I'm winching at low rpm the tree will catch on something and stalls my tractor and some how the motor starts running backward, I have to shut it off and re-start, weird and sounds different to, that ever happen to anyone else?

Is there a clutch and if so can you adjust it to release before it stalls

 

[John_Mc]

Does anyone use 230' of cable? I'd cut that in half, mine holds around 140' and that's more then enough.

95+% of the time when I'm harvesting sawlogs or firewood, I probably use less than 150'. When clearing for a new trail, I'll use everything I have, and occasionally ad a length of chain to that. Often the trail is too rough or has too much side slope to take my tractor on until we get a dozer or excavator in to pull the stumps and put the final grade on the trail.

Unless I have a nice straight pull with good visibility (a rarity in the woods around here), it's very tough to use the full length without an extra person to act as a spotter. Maybe if I had a remote control winch, I could do it alone, but I prefer to have someone within sight of the tractor as well.

 

[John_Mc]

I once almost pulled my 275 over backward with my beat up old Fransgard. I was watching the twitch and trying to get it to come up over a stump. Something didn't sound right so I looked at the tractor and backed off just before it got the the point of no return... the closest I've ever come to flipping. Granted that winch was old and probably out of spec but still...

I'm having trouble picturing how that could happen. If I were driving and pulling a load and it caught on a buried stump maybe, since the rear tires are providing some rotation. But sitting stationary with the butt plate of the winch on the ground? Does your winch not have a lower pulley so you can winch from down low? Even without the lower pulley, the pivot point would be where your butt plate meets the ground. It would require basically lifting up the tractor by the top link of your 3 pt hitch.

 

[Agvg]

Often you want height when you pull, very seldom I use the lower pully, and it's no problem to lift the front up I the air on a smaller tractor when winching, and if you transport out the logs hanging by the wire the wheels easily goes up in the air.

 

[CobyRupert]

I want all the cable that can fit on the reel.

True, that 90% of the time when pulling logs I use 100' of cable or less, I often use the winch as a "plan B" helper when cutting a tree that absolutely-positively has to fall in the direction I want it to.

In these situations, and other situations too, I might to "double up" the cable through a snatch block at the tree to double the pulling force, which is something I DON'T want to run out of when I have the tree 90% cut.

So with a 165' cable the most I can be away from the tree is around 82'. This can be too close for comfort when pulling over some big trees.

 

[John_Mc]

Often you want height when you pull, very seldom I use the lower pully, and it's no problem to lift the front up I the air on a smaller tractor when winching, and if you transport out the logs hanging by the wire the wheels easily goes up in the air.

During transport I can easily see how it could happen (as I mentioned in my previous post). During winching with a logging winch is what I'm having trouble with. The pivot point would be where the winch blade meets the ground. I've never even seen mine get a little light in the front end, let alone lift up, since the forces during winching aren't creating a pivot around the rear wheels. But if it happened to you, I guess it's possible. I'm using a Uniforest 35E (rated for 7700# pull - very similar to a Farmi 351 or a Fransgard V-3507) behind a NH TC33D (2400# bare, probably between 4200 and 4500# as I have mine set up).

 

[Jstpssng]

There's no down pressure on the 3 pth, so the winch does nothing as far as keeping it from coming up. I only had the problem once to that degree and I was more concerned with getting the tractor on the ground than analyzing it. I had an old Fransgard which I had mostly reworked; new chain, all 8 bearings, new cable. I had taken the drum out and had it turned to resurface it. I doubt that anything was up to spec; the A-frame eventually got bent so badly from the entire unit getting dragged backward that the chain rubbed a hole through the steel housing. The entire setup probably weighed about 3200 lbs.
Before I learned it's limitations I was dragging out hardwood twitches which must have approached the weight of the tractor; 2 big maples plus a few smaller trees, thrashing and tearing, at times pulling myself forward with the bucket. It's a wonder that I never broke anything.

I now have a newer, heavier tractor and a Uniforest 35M; but don't bring out nearly as I used to with that old setup.

 

[Oldpath05]

Is there a clutch and if so can you adjust it to release before it stalls

There's only two adjustments I want on my winch, fully on and fully off, the rest I'll rely on eyesight and my cat like reflexes.

 

[Jstpssng]

^^^^^
:thumbsup: :laughing: :cat: