PTO drive is best actualy.
Efficient, and stylish.
My winch has a pulling force of 6Kn at middle filled cable drum.
And its PTO driven, by a 3 cylinder VTZ tractor that has 50 horses only.
We are specialised at rough terrain forestry. The tractor is only 2 tonns , the winch is 350 Kg.
It is a DIY make, consisting a verry large clutch and a bend brake.
The tricky part was setting the hegight where the force of pulling attacks the tractor.
It has to be less then rear wheel radius. Otherwise it trys to flip the tractor.
Allso, the 3 point hitch arms have been modified, the blade of the winch is verry close to the tractor.
This is to reduce weight shifting towards the rear axle.
The winch has a rather large blade, bit over an inch thick.
The tractor 3 point hydraulics is bi-directional, it can push the blade down.
Prior winching anything the blade gets pushed down as mutch as possible.
The blade should be as wide as the whole tractor.
When doing a heavy pull the blade does dig in, roughly a feet or so.
Usualy i park the tractor with a stump behind it, that stops it from being pulled back.
I did have commerical winches, but none of them have preformed as good as the current diy make.
Reasons:
-> blade size was too small
-> structure of the wich was not strong enough
-> bad force attack point
-> winch was too far behind the tractor, shifting the point of weight towards the rear too mutch, reducing effective tractive efforth.
The bottom part (round 3/4 feet) is bendt in 45 degree, once the tree is winched to the tractor and i lift the whole thing it helps to support the weight. Allso i need not to winch the tree stiff right to the blade, that would make steering difficult.
The largest trees this 2 tonn 50 hp russian tractor can pull (with all of its branches as a whole, same condition it was felt) is diameter of 2 feet at base. Keep in mind we mostly work at flooded areas. This is a small 4x4 tractor, was choosen becouse its small. I can navigate with ease where larger machinery could not even get to. Roboust and simple. By simple i mean air cooling, 8 speed forward and 6 backward, it won't get any simpler than that.
I think a proper winch size is roughly 2 times more pulling force at mid drum, then the tractor weight including the winch it self. Winching has a significant traction advantage over drive away.
PTO drive is easy to make, tractors with multiple PTO speeds have advantage of multi-speed winching, great if you have to work with long cables. Less likely to fail than hydraulic drive, and not even nearly as expensive to make.
You can not stall the engine with hydraulics, that allso means you can not use all avaialable engine power.
Even that small portion is reduced , hydraulic pumps and motors are both not more effcient than 90%.
see for your self,
Hydraulic Oil Pumps - Horsepower Required
this site shows how to calculate the hp demand of a pump (roughly)
Now, you know the maximum pressure you have and flowrate, and will notice that most tractor hydraulics are under 30 hp even for large tractors.
PTO drive can utilise all available engine power, ad the required gearing canbe as simle as 2 gears.
angular bevel gears, that is.